ch.11
A single pane of glass has an R factor of about -.5 1 2 5
A hydronic heating system uses ___________ to heat a home. -HOT WATER Hot air Radiant energy Geothermal energy
Low flow toilets require a maximum of ______ gallons per flush. -1.6 1.8 2.1 2.3
A tankless coil water heater is part of what kind of heating system? Hot air -HOT WATER Steam Geothermal
AIR CONDITIONING In the southern parts of the country and in the tropics, houses may have little or no heat. The air conditioning system is the most important. We discussed the basics before. As a liquid turns into a gas, it absorbs heat and as it cools, it gives off heat. There will be cooling units inside the house. They may be located in walls, basements, or attics. The condenser will be located outside ideally on the north or east side. Cool air is distributed by fans through a duct system. It may be combined with a hot air heating system and use the same ducts. Ducts should be insulated. Air conditioning systems need to be properly sized for the building according to: Building volume Window area Insulation R-factors Appliance heat output Solar orientation Humidity levels in climate In 2012, 89% of new houses were built with central air conditioning.
AIR CONDITIONING CONT. Check the Seasonal Energy Efficiency Rating (SEER) label. Since 2006, all new air conditioners must have a minimum SEER rating of 13 - the maximum is 18.
Drainage Field The tile should be only about a foot or so beneath the surface. The water will eventually filter down through the gravel and the ground underneath it and be purified. This is the same principle as a sand and gravel filter for a swimming pool. Most water will eventually seep in the underground water table and be reused. But some of the water will leach its way to the surface and be evaporated. Over time, a drainage field may become saturated with water and unable to function. Then it may have to be excavated and replaced or extended.
Above Ground Mound If the soil conditions are particularly bad or space is limited, an above ground mound system may have to be employed. Sand and gravel are mounded up to create a favorable environment for drainage. This may or may not entail a sewage pump to pump the water up into the mound. Some systems also employ storage tanks where the wastes are collected and then injected under pressure with a pump, when the storage tank is full. If you have to resort to systems like this, they will work, but are expensive. They may run up to $20,000 or more. They also use mechanical parts, like pumps, which may need periodic maintenance or replacement.
What kind of water heater is two to three times more energy-efficient than a conventional electric water heater? Gas Oil -HEAT PUMP Indirect
According to the EPA, the most energy-efficient, environmentally clean, and cost-effective space conditioning systems available are Electric heat pumps -GEOTHERMAL HEAT PUMPS Forced hot air heating systems Active solar heating systems
Solar Water Heating Systems Solar water heating systems include storage tanks and solar collectors. There are two types of solar water heating systems: active, which have circulating pumps and controls, and passive, which don't. Most solar water heaters require a well-insulated storage tank. Solar storage tanks have an additional outlet and inlet connected to and from the collector. In two-tank systems, the solar water heater preheats water before it enters the conventional water heater. In one-tank systems, the back-up heater is combined with the solar storage in one tank. There are three types of solar collectors that are used for residential water heating: Flat-plate collector Glazed flat-plate collectors are insulated, weatherproofed boxes that contain a dark absorber plate under one or more glass or plastic covers. Unglazed flat-plate collectors, which typically might be employed for solar pool heating, have a dark absorber plate, made of metal or polymer, but without a cover. Integral collector-storage systems ICS or batch systems use one or more black tanks or tubes in an insulated, glazed box. Cold water passes through the solar collector, which preheats the water. Then, the water continues on to a conventional backup water heater. These systems should be installed only in mild climates because the outdoor pipes could freeze in cold weather. Evacuated-tube solar collectors These collectors have parallel rows of transparent glass tubes. Each tube contains a glass outer tube and metal absorber tube attached to a fin. The fin's coating absorbs solar energy but inhibits radiative heat loss. These collectors are used more frequently for commercial applications.
Active Solar Water Heating Systems There are two primary types of active solar water heating systems. Direct circulation systems This type of system employs pumps to circulate water through the collectors and into the home. They work well in climates where it rarely freezes. Indirect circulation systems With this system, pumps circulate a non-freezing, heat-transfer fluid through the collectors and a heat exchanger. This heats the water that then flows into the home. These systems can be used in climates prone to freezing temperatures.
Wiring - BX In the 1940s and 1950s, BX or armored cable was common. There were two wires and a ground inside a metal jacket that protected the wires. It was a good system for interior wiring of a house but the cable was hard to work with because it was difficult to cut and didn't bend very well.
Aluminum Wiring Aluminum wiring was used for a short period of time in the mid-1950s, due to a shortage of copper during the Korean War. It proved to be a fire hazard, in many instances, as the aluminum was subject to oxidation where it joined the electric boxes and receptacles.
EFFICIENTY RATINGS This information is from the U.S. Department of Energy. "A central furnace or boiler's efficiency is measured by Annual Fuel Utilization Efficiency (AFUE). The Federal Trade Commission requires new furnaces or boilers to display their AFUE. Specifically, AFUE is the ratio of heat output of the furnace or boiler compared to the total energy consumed. An AFUE of 90% means that 90% of the energy in the fuel becomes heat for the home and the other 10% escapes up the chimney and elsewhere. AFUE doesn't include the heat losses of the duct system or piping, which can be as much as 35% of the energy for output of the furnace when ducts are located in the attic, garage, or other partially conditioned or unconditioned space." That's why it's important to insulate the heating (and cooling ducts) "Beginning on May 1, 2013, for non-weatherized furnaces and January 1, 2015, for weatherized furnaces, the minimum AFUE requirements will be as follows: PRODUCT CLASS MINIMUM AFUE RATING Non-weatherized gas furnaces (not including mobile home furnaces) 80% Mobile home gas furnaces 80% Non-weatherized oil-fired furnaces (not including mobile home furnaces) 83% Mobile Home oil-fired furnaces 75% Weatherized gas furnaces 81% Weatherized oil-fired furnaces 78% Electric furnaces 78%
COMPARATIVE HEATING EFFICIENCY This table, provided by the U.S. Department of Energy, compares the average efficiency ratings of various heating systems.
What is the minimum acceptable SEER rating for an air conditioner? 10 -13 15 18
Chapter Summary In this chapter, we surveyed basic plumbing systems, including water heating systems. We illustrated and discussed plumbing distribution and drain/waste/vent systems. We investigated drainage systems, piping, and the potential uses for grey water. Then, we illustrated and analyzed the various kinds of systems for heating domestic hot water. These included hydronic heating systems, conventional storage tanks, tankless, heat pump, and solar water heating systems. We described the components of private water systems, such as dug wells, artesian wells, and drilled wells. We also considered the elements of private sewage systems. We covered electrical systems beginning with discussions of voltage and amperage. Different types of wiring were shown. There were explanations of how photovoltaic cells can generate electricity. We next investigated heating, ventilating, and air conditioning systems (HVAC). First, we addressed insulation. We discussed how it works and described various kinds of insulation, including some new, sustainable types. We illustrated and compared R-factors and U-factors. Then, we explained the importance of proper ventilation and described various methods of ventilation. We talked about types of mechanical ventilation and heat recovery ventilators. We explained energy-efficient windows and how low-E glass works. We delved into all the different types of heating systems including hot air heat, hot water heat, radiant heat, electric heat, heat pumps, geothermal heating systems, and solar heating systems. Finally, we discussed cooling systems including air conditioning, heat pumps, evaporative coolers, and simple fans.
Indirect Hot Water Heaters If you have a hot water heating system, but live in a cold climate, an indirect water heating system may be a better bet. It employs a separate storage tank. An indirect water heater uses the main boiler to heat fluid that is circulated through a heat exchanger in the storage tank. The energy stored by the water tank does not require the boiler to cycle off and on as frequently. An indirect water heater used with a high-efficiency boiler and well-insulated tank can be the least expensive means of providing hot water.
Conventional Tank Systems A conventional storage tank water heater is still the most popular type of system even though it employs 100-year old technology and is only about 55% to 60% efficient. The tanks vary in size from 20 gallons to 80 gallons.
RADIANT HEAT CONT. Radiant heat advantages are: Doesn't dry out the air No air or dust blown around No convectors or registers to complicate furniture arrangement Less heat loss to outside air infiltration Can reduce the heat load in a well-insulated house by 25% to 35% over conventional convective systems Radiant heat was utilized in the 1950s and 1960s but the technology was not too advanced and there were maintenance problems. We are seeing a resurgence of popularity today in new construction - but obviously, it's hard to retrofit an existing house with this type of system. There are two types of radiant heating systems in common use: electric and hot water. The electric cables may be installed in the ceiling or a slab floor. The hot water pipes are usually buried in a slab but may also be run between conventional floor joists. If the hot water pipes are in a slab, the concrete also gets heated and radiates heat.
ELECTRIC RADIANT HEAT Electric radiant heat has the advantages of having no boiler, no chimney, no parts or valves to wear out, and no pipes to freeze. Hot water radiant heat costs less to install and operate. New types of plastic pipe can withstand freezing and corrosion. Because the water only needs to be heated to between 90 and 120 degrees, a small boiler or hot water heater can be utilized at considerable energy savings. Zoning is simple.
HEAT PUMPS Don't forget what we discussed earlier in our discussion of heat pumps. We said that in cold parts of the country, heat pumps are not as efficient for heating purposes. However, they are viable for heating in warmer and moderate parts of the country and are capable of performing their function of cooling air in all parts of the country. They are an energy-efficient way to cool buildings. They consume relatively little electricity and have few moving mechanical parts. Basically, they consist of a compressor, condenser, and some fans. According to the Census Bureau, 38% of new houses in 2012 were built with heat pumps, which supply both heat and cooling.
EVAPORATIVE COOLERS Sometimes called swamp coolers, these are comparatively primitive systems but can be effective in dry climates, such as Arizona and the Southwest. Outside dry air is pulled through a water-soaked pad by a blower. As the air passes through, it becomes cooler, but moister. As the water in the air evaporates, the air becomes cooler. Most are roof-mounted systems whereby the cooled air is forced through ceiling registers. When the thermostat calls for it, a pump sprays water on an absorbent pad. A float valve maintains a constant water level in the unit's cooler pan.
Mounds A good description of sand mounds was obtained from the former toolbase.org site. "Slowly permeable soils, shallow permeable soils over a limiting layer (clay or rock), or permeable soils with high water tables, can accept leachate by the use of an elevated soil absorption bed called a mound. Mounds require more care than conventional systems in site selection, design, and construction. This is partly because the soil and site characteristics are marginal, special sand is required, and contractors are apt to be less experienced with mound construction techniques. Proper location and soil preparation are essential for a properly functioning mound. Mounds should be as long and narrow as the site permits, on either flat or sloping topography. A long, narrow mound will minimize the "mounding" of the groundwater table under the absorption bed. Treatment is further enhanced by using a dosing pressure distribution system (see below). 7 to 8 inches of soil under the bed is plowed or roughened to enhance absorption, and the calculated depth of sand is added. Monitoring wells are installed to check conditions within the bed, at its edges and below the field. Distribution piping is laid on 6" of aggregate and covered with 2" of the same material, covered with filter fabric and soil, laid at a maximum slope of 1 in 4. Because of their higher cost, mounds are installed only on sites where conventional absorption systems are not suitable." End of Page
Electrical Systems Voltage = PressureAmperage = Volume The best analogy is to compare electricity running through a wire to water flowing through a hose. The volts are the pressure that is pushing it (similar to pounds per square inch of water pressure) and the amps are the total volume that will fit through the hose (similar to gallons per minute of water). Power will be delivered from a utility pole to a building via three wires - two wires are hot and the third is neutral. The wires may run through the air as three separate wires, or as a braided triplex wire. Of course, they may also be buried under the ground. If you measure the voltage across both hot legs, it will be 240 volts. Between either hot leg and the ground, it will be 120 volts. These are nominal voltages but they vary a little between 110 and 120 and between 220 and 240 volts. We need more power - more pressure - to run certain items. Electric dryers, electric ranges, and heavy duty power equipment run on 220/240 volts. Normal receptacles, lighting, small appliances, computers, etc. run on 110/120 volts. Certain things like doorbells and thermostats require little in the way of power and have transformers that reduce the power to only 12 volts. 12 volts is a minimal amount of pressure and will not harm you. 110 volts will give you a nasty shock, and 220 can kill you! The power comes in through the meter to a service panel. There it is divided into branch circuits. These serve various parts of the house and each is protected by a fuse or a circuit breaker, in the event of an overload. Fuses contain a small metal strip that melts in the event of an overload and breaks the circuit. Breakers act in the same way and are no more than a mechanical fuse that can be reset, instead of being replaced. If there is an overload, the breaker trips and the circuit is broken, but it can be reset by rocking the breaker back into position. Fuses are rarely used in new construction anymore, but are adequate. If there are enough circuits and enough amperage in an existing installation, fuses don't need to be replaced with breakers - except for convenience.
FANS A certain amount of cooling can be accomplished with ordinary fans. Whole house or attic fans can evacuate a great deal of hot air and replace it with cooler air from the outside, or perhaps a basement. Fans in an attic can move out hot air before it infiltrates the interior of the house.
Evaporative cooling systems are used primarily in the Northeast Southeast -SOUTHWEST Midwest
ELECTRIC HEAT PUMPS Heat pumps are simply reversible air conditioners. They can heat in the winter and cool in the summer. They use a refrigerant to pick up and discharge heat. This refrigerant is naturally a liquid but turns into a gas when it absorbs heat. Compressing the liquid helps it absorb heat. Then the gas is run through a condenser to cool it down, give off heat, and become a liquid again. For years, Freon R-22 was the refrigerant of choice in home air conditioning; however it is no longer permitted for use in new construction because it has been shown to damage the Earth's ozone layer. Today's environmentally-friendly refrigerants are manufactured under the brand names Puron, Genetron AZ-20, and Suva 410A. Heat pumps use very little energy and have few moving parts. The problem is that they are inefficient once the outside air gets below about 40 degrees. In northern climates, they need back-up systems for heating but will work well for cooling. They are a relatively slow form of heat as the heated air entering a room is considerably cooler than that supplied by a hot air heating system.
GEOTHERMAL HEAT PUMPS Geothermal systems usually employ high density polyethylene pipe. It is buried 4 to 6 feet deep for horizontal applications and may run from 100 to 500 feet deep for vertical applications. The pipes are filled with water or a non-toxic antifreeze solution. They are unobtrusive, low maintenance systems and can give you free domestic hot water as a bonus. According to the EPA, GeoExchange systems are the "most energy efficient, environmentally clean, and cost effective space conditioning systems available." Residential systems do cost more to install initially but because of their greater efficiency, the cost can be recouped in 2 to 10 years. They may become more competitive as advancements are made in technology. There are four basic systems, depending on the amount and type of land you have and the presence or absence of water. Two extract heat energy from the ground and two from water. Once you get down 4 or 5 feet, the temperature of the ground stays between 50 and 55 degrees year round. Water holds heat well and even in the winter, when the surface freezes, it is warmer below.
Plumbing Systems - Drainage The drainage system carries off waste water. Greywater from the sinks and laundry is carried off in drain lines and may vary from 1½ inches to 3 inches. Greywater is water that has been used in the home, except water from toilets, dishwashers, and kitchen sinks. Water from dishwashers and kitchen sinks is not considered greywater because it may have been contaminated by contact with bacteria in food wastes. Water from showers, sinks, and laundry water comprises 50-80% of residential "waste" water. In a typical home, this may amount to more than 5,000 gallons a year. Greywater may be recycled for uses such as watering lawns and landscaping, flushing toilets, and even washing cars.
Greywater This again is from toolbase.org; "Greywater is wastewater from bathtub, shower drain, sinks, washing machines, and dishwashers. Greywater accounts for 60% of the outflow produced in homes. It contains little or no pathogens and 90% less nitrogen than black water (toilet water). Because of this, it does not require the same treatment process. By designing plumbing systems to separate it from blackwater, greywater can be recycled for irrigation, toilets, and exterior washing, resulting in water conservation. When planned into new residential construction, the home's wastewater treatment system can be significantly reduced, resulting in cost and space savings. Systems generally consist of a three-way diverter valve, a treatment assembly such as a sand filter, a holding tank, a bilge pump, and an irrigation or leaching system. The holding tank cools the water and temporarily holds it back from the drain hose. Systems can either be custom designed and built, or purchased as a package. Techniques include recessed or raised planter soilboxes, water injection without erosion, gravity or pressure leach chamber, and irrigated greenhouses. Some system components can retrofit existing irrigation systems." Note that in the article, it states sources of greywater include dishwashers. This is a source of some disagreement in the industry, but it is generally believed that dishwasher discharge water can contain bacteria from food wastes, and is therefore not greywater.
A new kind of sustainable spray insulation that expands and hardens up to 100 times its size is based on Corn oil Recycled plastic water bottles -SOY Glucose
Greywater constitutes about _____ % of residential waste water. 30 40 -60 80
Demand (Tankless) Water Heaters Demand (tankless or instantaneous) water heaters provide hot water only as it is needed and can produce significant savings over conventional storage tank systems. Demand water heaters heat water directly without the use of a storage tank. Therefore, they avoid standby heat losses. When hot water is called for, cold water travels through a pipe into the unit. Either a gas burner or an electric element heats the water. So, demand water heaters deliver a constant and instant supply of hot water. However, a demand water heater's output limits the flow rate. Typically, demand water heaters provide hot water at a rate of 2-5 gallons per minute. Gas-fired ones produce higher flow rates than electric ones. However, even the largest gas-fired model cannot supply enough hot water for taking a shower and running the dishwasher at the same time. That kind of demand can stretch a tankless water heater to its limit. They need to be sized properly for the household. You can install two or more demand water heaters, connected in parallel for simultaneous demands of hot water. You can also install separate demand water heaters for appliances - such as a clothes washer or dishwasher - that use a lot of hot water in your home. For homes that use 40 gallons or less of hot water daily, demand water heaters can be 24%-34% more energy-efficient than conventional storage tank water heaters. They can be 8%-14% more energy-efficient for homes that use a lot of hot water - around 86 gallons per day. You can achieve even greater energy savings of 27%-50% if you install a demand water heater at each hot water outlet. Tankless water heaters currently cost more than conventional storage water heaters. However, a demand water heater should have lower operating and energy costs, which could offset its higher initial cost. As they become more common and technology improves, the purchase prices will come down. They are very reasonable in Japan as they have been commonly used for more than 20 years. Gas-fired demand water heaters tend to have higher flow rates than electric ones, but they can waste energy if they have a constantly burning pilot light. Some models have an intermittent ignition device (IID) instead of a standing pilot light. This device resembles the spark ignition device on some gas kitchen ranges and ovens.
Heat Pump Water Heaters Heat pump water heaters use electricity to move heat from one place to another instead of generating heat directly. Therefore, they can be two to three times more energy-efficient than conventional electric water heaters. To move the heat energy, heat pumps work like a refrigerator in reverse. A refrigerator makes cool air through the use of a compressor and then gives off warm air as a by-product through the use of a condenser and coil. A heat pump water heater pulls heat from the surrounding air and transfers it into a tank to heat water. Heat pump water heaters should be installed in a space with excess heat, such as a furnace room. They will not operate efficiently in a cold space. They tend to cool the spaces they are in. Heat pump water heaters require installation in locations that remain in the 40º-90ºF range year-round and provide at least 1,000 cubic feet of air space around them. Cool exhaust air can be evacuated to the room or outdoors. Let's pause here and check your understanding, and then we will turn our attention to solar water heaters.
Mechanical Ventilation (cont.) From the EPA's website: Amount of Ventilation If too little outdoor air enters a home, pollutants can accumulate to levels that can pose health and comfort problems. Unless they are built with special mechanical means of ventilation, homes that are designed and constructed to minimize the amount of outdoor air that can "leak" into and out of the home may have higher pollutant levels than other homes. However, because some weather conditions can drastically reduce the amount of outdoor air that enters a home, pollutants can build up even in homes that are normally considered "leaky". How Does Outdoor Air Enter a House? Outdoor air enters and leaves a house by: infiltration, natural ventilation, and mechanical ventilation. In a process known as infiltration, outdoor air flows into the house through openings, joints, and cracks in walls, floors, and ceilings, and around windows and doors. In natural ventilation, air moves through opened windows and doors. Air movement associated with infiltration and natural ventilation is caused by air temperature differences between indoors and outdoors and by wind. Finally, there are a number of mechanical ventilation devices, from outdoor-vented fans that intermittently remove air from a single room, such as bathrooms and kitchen, to air handling systems that use fans and duct work to continuously remove indoor air and distribute filtered and conditioned outdoor air to strategic points throughout the house. The rate at which outdoor air replaces indoor air is described as the air exchange rate. When there is little infiltration, natural ventilation, or mechanical ventilation, the air exchange rate is low and pollutant levels can increase. Ventilation Improvements For most indoor air quality problems in the home, source control is the most effective solution. Another approach to lowering the concentrations of indoor air pollutants in your home is to increase the amount of outdoor air coming indoors. Most home heating and cooling systems, including forced air heating systems, do not mechanically bring fresh air into the house. Opening windows and doors, operating window or attic fans, when the weather permits, or running a window air conditioner with the vent control open increases the outdoor ventilation rate. Local bathroom or kitchen fans that exhaust outdoors remove contaminants directly from the room where the fan is located and also increase the outdoor air ventilation rate. Advanced designs of new homes are starting to feature mechanical systems that bring outdoor air into the home. Some of these designs include energy-efficient heat recovery ventilators (also known as air-to-air heat exchangers).
Heat Recovery Ventilators A heat recovery ventilator (HRV) recovers most of the heat that would be lost in a typical ventilation system and returns it into the house. Imagine a device that has two fans. One is used to exhaust polluted air to the outside and the other is used to replace the exhausted air with fresh air from the outdoors. Suppose it is a winter day and you have the interior of your house heated to 70 degrees. You pull out some of that nice warm air and replace it with 20 degree air from the outdoors. Now your heating system has to heat that up 50 degrees and consumes a lot of energy in doing so. An HRV can capture up to 85% of the escaping heat in the exhausted air and reintroduce it into the incoming stream of fresh air. It also contains filters that keep particulates such as pollen or dust from entering the house. It can also function in the summertime to capture some of the cooled air that is being exhausted and use it to temper the warm air coming in from outside. You may also hear the term energy recovery ventilator. They operate in a similar fashion but recover the moisture from outgoing air along with the heat and replace it in incoming air.
The size of a septic tank is usually linked to the number of ______ in a house. Square feet Baths Fixtures -BEDROOMS
Heat pumps are not very efficient when the outside air is below approximately ______ degrees. 70 60 50 -40
Heating Systems Up until about 1840, all houses were heated by fireplaces. Then metal wood-burning stoves were introduced. Usually they were employed in several different rooms. The modern central heating system, with one central furnace, didn't appear until around 1880. At first, they too burned wood but evolved through coal, oil, gas, electric, etc. Hot Air Heat For many years, the hot air furnaces were pipeless. They were known as gravity furnaces. As the air was heated, it rose through a floor register, and as it cooled, the air fell back down (by the force of gravity) to be re-heated and sent up again. Grates were cut in the floor of the second story in an attempt to get heat upstairs. Some heat did ultimately find its way up there, but it was not very efficient. The next generation of heating systems had multiple registers in the floor but it still was not ducted to each room and there were no fans. The air simply rose when warmed. Because of its physical appearance, it was known as an octopus system. End
Hot Air Heat The modern forced hot air system employs fans to move the air around and ducts to supply heat to every room. The air can also easily be filtered or humidified. Hot air heat warms a room rapidly and the ducts can be used for air conditioning. The disadvantages are that it is noisy and blows hot, dusty air around. The ducting system makes it difficult to retrofit. In 2012, 58% of new houses were built with hot air heat.
Steam Heat Steam heat was popular in the early 1900s but is rarely seen today in new construction, other than retail or offices. Water was heated until it turned to steam and the steam was carried through pipes to big, old radiators. Some were two-pipe systems with one for supply and the other for return. Some were one-pipe systems where the steam cooled, condensed, and ran back to the boiler through the same pipe. Steam heat was relatively efficient as the cast iron radiators retained heat for a long time. However, there were many disadvantages: the radiators got very hot, could cause burns, and restricted furniture placement. The systems were noisy and needed attention, such as refilling the water.
Hot Water Heat In this system, water is heated in a boiler and sent through pipes to each room, where it gives off heat through convectors. As the water is heated, it expands and temporarily goes up into the expansion tank. The water is pulled through the lines by a circulating pump. Some old steam systems were converted to hot water and utilized the original radiators. Modern systems usually employ baseboard units. The water runs through copper pipes and heats up aluminum fins that are attached to the pipe. This sets up convection currents and air passes around the fins and is heated. Hot water heat is a relatively efficient system as water retains heat for a long time. It is cleaner than hot air and less drafty. It is easy to zone for different areas. Disadvantages are that even the baseboard radiators restrict furniture placement and the pipes could freeze and burst if the power goes off. Also, the water in the pipes is susceptible to air blockage and may corrode the pipes. In 2012, only 2% of new houses were built with hot water heat. After checking your understanding, we will examine radiant heat.
Domestic Water Heating Systems After the costs of heating or cooling a home, usually the second most expensive utility bills come from heating domestic hot water. According to the National Renewable Energy Laboratory, costs average nationally about 13% of total energy bills in residences. It can run as much as 25% or higher. There are various types of systems with significantly different efficiency rates and costs. We will look at them individually over the next pages.
Hot Water Heating Systems If a home has a hot water (hydronic) heating system, there is a built-in bonus. The same boiler that provides hot water to heat the house, through radiators or baseboard convectors, can be used to heat and distribute domestic hot water throughout the house. A tankless coil water heater uses a heating coil or heat exchanger installed in a main furnace or boiler. Whenever a hot water faucet is turned on, the water flows through the heat exchanger. This type of system works most efficiently during cold months when the heating system is used regularly. It can be an inefficient choice for homes in warmer climates.
How are PEX plumbing joints fastened together? Soldering iron Glue Mastic -A CRIMPING TOOL
In a typical drainage field, how deep should the drain -1 FOOT 3 feet 4-5 feet 6 feet or more
Photovoltaic (PV) Panels (cont.) A number of solar cells electrically connected to each other and mounted in a support structure or frame is called a photovoltaic module. Modules are designed to supply electricity at a certain voltage, such as a common 12-volt system. The current produced is directly dependent on how much light strikes the module. Multiple modules can be wired together to form an array. In general, the larger the area of a module or array, the more electricity that will be produced. Photovoltaic modules and arrays produce direct-current (DC) electricity. They can be connected in both series and parallel electrical arrangements to produce any required voltage and current combination. The direct-current (DC) electricity has to be run through a convertor to produce alternating-current (AC) electricity for common household usage. En
Insulation Some materials transfer energy more quickly and are called conductors. Good conductors include such things as metal and stone. If you sit on a stone bench, your rear end gets cold because the stone quickly conducts away the body heat. Poor conductors, or insulators, include plastic and air. That's why we move electricity through a copper wire encased in plastic. We can insulate a wall with cellulose fibers with lots of air spaces. Down parkas work well because of the air spaces in between the feathers. If they get damp or the down gets matted, it doesn't insulate very well. R-factors Heat energy will flow from warm areas to cold areas. We can retard the flow but can't stop it. The measure of resistance to heat transfer is called an "R" factor. To give some perspective, an inch of wood has an R factor of about 1. Depending on where you are, the desired R-factors may be something like R-13 in the floors, R-19 in the walls, and R-30 in the ceilings. That would take a lot of wood! Thankfully, modern insulations have been developed that will help us accomplish those factors. Click here for more information about R-factors. Here are the most common forms of insulation. Each has advantages and disadvantages. Cellulose - loose fill Blown-in insulation Styrofoam panels UFFI Batts and rolls of fiberglass and other materials Fiberglass rolls or batts are most commonly used. A batt is a pre-cut length of insulation (usually 8 feet or so) that you can just press into a wall cavity between the studs. Cellulose or blown-in insulation tends to settle down and compress over time and can get matted when damp. UFFI had a short history of usage and was found to give off hazardous fumes. Styrofoam or other rigid forms of insulation are utilized in some applications - such as ceilings or foundation walls. There are some new sustainable insulation materials that we will address as well. End of Page
Windows Everybody loves windows. It's nice to have all that light in the house and they can help with ventilation. But from an insulation standpoint - they're a disaster! A single pane of glass has an R-factor of 0.5. Two panes, with an air space, make about R-1.5, and even triple panes with two air spaces have an R-factor of only about 2.5. You might as well have a big hole in the wall to let in all that cold air. If nothing else, have fewer windows on the north side and more on the south. You can increase the insulating capacity in modern windows by filling the air cavity between the panes of glass with a gas. Typically Argon gas is used - it is inexpensive, non-toxic, non-reactive, clear, and odorless. Where the space is thinner than usual, Krypton gas may be employed. Of course, it's important to put them in straight! U Factors Here are U-factors that can be achieved. Remember - with U-factors, the lower the number, the better. This is just the opposite of R-factors. Type of window U Factor Single pane - clear glass 5.4 2 panes - clear glass 2.6 2 panes - Low-E Coating 1.8 Above with argon gas 1.6
Low - E Glass The sun's energy passes through glass as short wave radiation and is absorbed by carpeting, furniture, etc. Then it is transmitted as heat energy or long wave radiation, which wants to flow from warm air to cool, and much will pass back out through the windows. Low Emittance (Low-E) glass has a coating on the inside to reflect it back. Different types of coating may be applied to admit more or less solar gain, depending on the climate. In the summer or in warmer climates, it is desirable to have less sun come through. Low - E glass advantages are: Better heat insulation Reduced carbon dioxide into the atmosphere Reduced condensation on the interio
The second highest utility expense in typical residences is Heating Cooling Lighting -HOT WATER
Low-E glass stands for low ____________. Emissions Environment -EMITTANCE Entry
Which type of heating system allows the air to be filtered or moisturized MOST easily? Hot water heat Steam heat -HOT AIR HEATER Radiant heat
Low-E glass stands for low ____________. Emissions Environment -EMITTANCE Entry
Ventilation Ventilation goes hand-in-hand with insulation. Moisture is the enemy of most types of insulation. When insulation gets moist, it packs down and the insulating air spaces get compressed, thereby reducing its effectiveness. Moisture inside a house must be contained and evacuated through proper means of ventilation. Moisture in the building structure can lead to mold growth, peeling paint, and rotting wood. As houses have been built more "tight" in recent years, this is more important than ever. Super-insulation may be counterproductive, if the house can't breathe. There should be a vapor barrier on the heated side of a wall so that warm, moist air inside the house is prevented from entering the wall cavity. This is to be avoided because once it gets inside the wall, the warm moist air cools, condenses, and soaks the insulation. Moisture inside the house is produced by many things: People breathing - 2.8 lbs/day/person Plants Showers - ½ lb each Hot tubs, pools Dishwashers Washers and dryers Cooking - 4.7 lbs/day Common methods of ventilation include: Attic fans Kitchen fans Vents - basement and crawl space Attic - ridge vents, perforated soffits Louvers Cupolas Mechanical air exchangers
Mechanical Ventilation Sustainable construction practices include a plan to force ventilation on a regular basis to introduce fresh air periodically into the interior and exhaust stale and toxic air to the outdoors. Indoor air quality is a major concern. The EPA says on its website: Indoor pollution sources that release gases or particles into the air are the primary cause of indoor air quality problems in homes. Inadequate ventilation can increase indoor pollutant levels by not bringing in enough outdoor air to dilute emissions from indoor sources and by not carrying indoor air pollutants out of the home. High temperature and humidity levels can also increase concentrations of some pollutants. There are many sources of indoor air pollution in any home. These include combustion sources such as oil, gas, kerosene, coal, wood, and tobacco products; building materials and furnishings as diverse as deteriorated, asbestos-containing insulation, wet or damp carpet, and cabinetry or furniture made of certain pressed wood products; products for household cleaning and maintenance, personal care, or hobbies; central heating and cooling systems and humidification devices; and outdoor sources such as radon, pesticides, and outdoor air pollution.
SOLAR HEAT Active solar heating systems depend on collector panels and a method to store excess heat - typically in water or rocks. Then the warm air is circulated through the house. They can be effective in certain parts of the country and, combined with good insulation, can be the sole source of heat. In colder or cloudier parts of the country, they may be ineffective or require back-up systems.
PASSIVE SOLAR SYSTEMS Passive solar systems employ common sense applications and are practical anywhere. They may include: South-facing windows Greenhouses Heat-storing surfaces - stone, concrete, water Low-E glass
PEX Plumbing In most new construction today, you will find PEX tubing. Here is a good explanation from www.pexinfo.com. "PEX (or crosslinked polyethylene) is part of a water supply piping system that has several advantages over metal pipe (copper, iron, lead) or rigid plastic pipe (PVC, CPVC, ABS) systems. It is flexible, resistant to scale and chlorine, doesn't corrode or develop pinholes, is faster to install than metal or rigid plastic, and has fewer connections and fittings. PEX tubing is made from crosslinked HDPE (high density polyethylene) polymer. The HDPE is melted and continuously extruded into tube. The crosslinking of the HDPE is accomplished in one of three different methods. PEX plumbing has been in use in Europe since about 1970, and was introduced in the U.S. around 1980. The use of PEX has been increasing ever since, replacing copper pipe in many applications, especially radiant heating systems installed in the slab under floors or walkways. Interest in PEX for hot and cold water plumbing has increased recently in the United States. Advantages of PEX Plumbing Flexible PEX tube is manufactured by extrusion, and shipped and stored on spools, where rigid plastic or metal piping must be cut to some practical length for shipping and storage. This leads to several advantages, including lower shipping and handling costs due to decreased weight and improved storage options. PEX plumbing installations require fewer fittings than rigid piping. The flexible tubing can turn 90 degree corners without the need for elbow fittings, and PEX tubing unrolled from spools can be installed in long runs without the need for coupling fittings. Attaching PEX tube to fittings does not require soldering, and so eliminates the health hazards involved with lead-based solder and acid fluxes; PEX is also safer to install since a torch is not needed to make connections. PEX resists the scale build-up common with copper pipe, and does not pit or corrode when exposed to acidic water. PEX is much more resistant to freeze-breakage than copper or rigid plastic pipe. PEX tubing does not transfer heat as readily as copper, and so conserves energy. Water flows more quietly through PEX tube, and the characteristic "water hammer" noise of copper pipe systems is virtually eliminated. PEX plumbing installations cost less because:PEX is less expensive than copper pipe.Less time is spent running pipe and installing fittings than with rigid pipe systems.Installing fewer fittings reduces the chances for expensive callbacks.
PEX Plumbing (cont.) The standard method for connecting PEX pipe to brass PEX fittings uses a copper crimp ring and a PEX crimping tool. The copper crimp ring is inserted over the pipe, the fitting is inserted inside the pipe, and the copper ring is crimped over the pipe and fitting using the PEX crimping tool. Tools, fittings and crimp rings are available from several suppliers. Information about testing standards for this method can be found on the ASTM standards page."
Non-metallic Wiring Since the 1960s, the most popular wires have been non-metallic wire, which is a plastic-sheathed copper wire. Romex is a brand name for one type of this wire, but some people refer to all non-metallic wire by the name Romex. The plastic coating is flexible and gives the wires adequate protection.
Photovoltaic (PV) Panels When we speak of solar energy today, typically, we are talking about photovoltaic (PV) panels. They take the sun's energy and turn it directly into electricity. This electricity can be used to power the house and light it. Here is a summary of how it works from the NASA website: Photovoltaics is the direct conversion of light into electricity at the atomic level. Some materials exhibit a property known as the photoelectric effect that causes them to absorb photons of light and release electrons. When these free electrons are captured, an electric current results that can be used as electricity. The photoelectric effect was first noted by a French physicist, Edmund Bequerel, in 1839, who found that certain materials would produce small amounts of electric current when exposed to light. In 1905, Albert Einstein described the nature of light and the photoelectric effect on which photovoltaic technology is based, for which he later won a Nobel prize in physics. The first photovoltaic module was built by Bell Laboratories in 1954. The diagram above illustrates the operation of a basic photovoltaic cell, also called a solar cell. Solar cells are made of the same kinds of semiconductor materials, such as silicon, used in the microelectronics industry. For solar cells, a thin semiconductor wafer is specially treated to form an electric field, positive on one side and negative on the other. When light energy strikes the solar cell, electrons are knocked loose from the atoms in the semiconductor material. If electrical conductors are attached to the positive and negative sides, forming an electrical circuit, the electrons can be captured in the form of an electric current -- that is, electricity. This electricity can then be used to power a load, such as a light or a tool. End of Page
Plumbing Systems - Waste Water Black water from the toilets is taken away by soil lines, which are usually 3-inch lines. "U"-shaped, water-filled traps are installed under each fixture to keep sewer gases from venting back into the house. The drain system funnels waste water into a stack (3 or 4 inch diameter), which leads out to the sewer or septic system. The stack must be vented to the outdoors to allow sewer gases to escape through the roof and to prevent water being siphoned from the traps.
Pipes Distribution lines have traditionally been copper, after bad experiences with galvanized iron pipes. Drain lines have traditionally been cast iron. In recent years, there has been general acceptance of plastic pipes, but they are still prohibited in some building codes. "Black Plastic" polyethyelene is flexible and permitted for cold water use only. It should not be utilized for distribution lines within the house but works well to bring in the water from the supply - well or public water. Polybutylene pipe is similar but has had poor acceptance with many codes due to earlier fitting problems. Rigid plastic pipe includes PVC and CPVC. PVC is approved only for cold water, but CPVC can be used to carry hot or cold water. Plastic pipe has largely replaced cast iron pipes in the DWV systems. However, white PVC pipe is not accepted by all codes. Black ABS plastic pipes are stronger and are generally acceptable today. There were some earlier class action suits due to cracking in some ABS pipes manufactured between 1984 and 1990.
Mechanical Systems Here we will look at the various mechanical systems that service a building. They are vital to the efficiency and livability. We don't have to be experts but should have a basic understanding of the way they work. You should observe and report the type and general condition of the mechanical systems you encounter in a property. They may require an adjustment in the sales comparison grid or a charge in the cost approach for functional inutility. The utility costs to operate a building are an important consideration today and may affect the marketability or ability to finance a home or investment property. If you see any signs of deterioration or leakage, you should at least comment on any apparent problems, photograph and document them, and perhaps recommend an inspection by a qualified professional.
Plumbing Systems Plumbing systems encompass two main systems: the distribution system and the drain/waste/vent (DWV) system. In addition, there may be a third sub-system with hot water or solar heating. The distribution system brings water, under pressure, into the house - usually through a ¾-inch or one-inch line. This divides into cold and hot water distribution lines that run to each fixture or appliance. Better quality systems use ¾-inch main lines and ½-inch branch lines. Lesser quality installations use ½-inch throughout. Good plumbing practice postulates: Keep piping runs as short as possible Put the water heater close to the main point of use Insulate supply pipes - both hot and cold In cold climates, do not run supply pipes in exterior walls and unheated areas Design the system so it can be shut down and drained easily Install shutoff valves on every fixture riser pipe
Low Flow Plumbing Fixtures It is now required that low flow plumbing fixtures be installed in new construction and remodeling projects. Here is an explanation from toolbase.org. "It's not just low flow, it's the law. In 1995, the National Energy Policy Act mandated the use of toilets that use no more than 1.6 gallons of water per flush. Since then, low-flow plumbing fixtures including toilets, faucet aerators and showerheads have been developed that save substantial amounts of water compared to conventional fixtures while providing the same utility. Different types of low-flow toilets use various technologies aimed at making the toilet more functional. Some toilets have large drain passages, redesigned bowls and tanks for easier wash down. Others supplement the gravity system with water supply line pressure, compressed air, or a vacuum pump. Conventional faucet aerators don't compensate for changes in inlet pressure, so the greater the water pressure, the more water you use. New technology compensates for pressure and provides the same flow regardless of pressure. Aerators are also available that allow water to be turned off at the aerator itself. Showerheads use similar aerator technology and multiple flow settings to save water. Low-flow toilets use a maximum of 1.6 gallons of water per flush compared with about 3.5 gallons of water used by a standard toilet. Low-flow shower heads use about 2½ gallons of water per minute compared to between four and five gallons per minute used by conventional heads. Low-flow faucet aerators can cut the water usage of faucets by as much as 40% from 4 gallons per minute to 2½."
Private Water Supplies About 40% of American homes have their own private water supply. Some areas with high water tables lend themselves to hand-dug wells or use of naturally-occurring springs. Hand-dug means just that someone dug a hole with a shovel until they hit water. Artesian wells are ones in which the water is forced to the surface by hydrostatic pressure and overflows all by itself. In some cases, a point (metal pipe with sharp end) is driven into the ground. Because these types of supplies lie near the surface, they are often subject to seasonal fluctuation and dry spells. They are also subject to pollution from surface runoff, unless protected and enclosed. They may require filters or purification systems. In some areas, cisterns to catch rain water are the most practical way to get a water supply. Rainwater is collected off the roof and stored in underground cisterns for future use. This is common in areas with low water tables or where the groundwater may be contaminated by salt water, such as the Virgin Islands. Deeper wells can be drilled or pounded into the ground. Steel or plastic casing is used until bedrock is reached. After that, the hole that is bored into the rock will be self-supporting and will not need casing. The depth to find potable water in adequate quantities can vary enormously. Local well drillers may be able to give you estimates of typical water depths and flows in an area. Ask how much it costs per foot for wells, and how much casing costs per foot. A normal, acceptable water flow would be about 3 to 4 gallons a minute. In some areas, even with a deep well, it is impossible to attain such a yield. It may be necessary to pump water more slowly into a storage tank to satisfy demand when needed. Another check of your understanding is next, after which we will cover septic systems. End of Page
ELECTRIC HEAT Electricity is sent through a resistor, which causes it to heat up. Air passes over the heated surface and warms the room by convection. In some cases, fans are also employed to move the air around. Electric baseboard heat has many advantages: there is a thermostat in every room, it is clean, there is no furnace or chimney needed, and virtually no maintenance is needed. It is practically a perfect heating system except for one factor - in most parts of the country, it is the most expensive system to operate because of the costs of the electricity itself.
RADIANT HEAT With hot air or hot water systems, the air is heated and it circulates around and eventually transfers heat to a person. With radiant heat, waves of radiant energy are transferred directly to your body. You can feel the warmth - like sitting near a wood stove or getting warmed by the sun. Also, everything else in the room gets warmed - the furniture, for example - which then warms the air for a period of time afterwards. Radiant heat is efficient and has fewer temperature extremes from floor to ceiling. You will be comfortable at temperatures 6 to 8 degrees less than with other forms of heat.
Septic Systems About one third of the houses in America use private septic systems. Older systems consisted of merely a cesspool (or cesspit). This was just a hole dug in the ground and filled with rocks or loose blocks so wastes would filter into the ground. In modern septic systems, the sewage leaves the house through a solid 4-inch line and goes to the septic tank. Older tanks were made of steel, but most today are concrete or fiberglass. Steel tanks generally have a life of 25 years or so, depending on conditions in the ground. The size of the tank is generally linked to the bedroom capacity of the house. For example - a 1,000-gallon tank for 4 bedrooms and a 1,250-gallon tank for 5 bedrooms. The tank serves as a settlement area. The solid wastes sink to the bottom and are mostly consumed by bacteria.
Septic Systems (cont.) The liquid waste, or effluent, leaves the tank as new wastes enter through a 4-inch solid line that goes to a junction box. Here the water is diverted into several directions and the water flows out into the drainage field or leach field through perforated tiles that allow the water to seep slowly out. The total amount, or lineal feet, of drain tile needed is determined by the character of the soil, as revealed through soilpercolation("perc") tests. The perforated drainage tile is laid in trenches filled with gravel, to promote drainage.
Passive Solar Water Heating Systems Passive solar water heating systems cost less than active systems, but they're not as efficient. However, passive systems can be more reliable and last longer. There are two basic types of passive systems. Integral collector-storage passive systems These work best in areas where temperatures rarely fall below freezing. They also work well in households that have significant daytime and evening hot-water needs. Thermosyphon systems In these systems, water flows through the system as warm water rises and cooler water sinks. The collector must be installed below the storage tank so that warm water will rise into the tank. These systems are reliable, but are usually more expensive than integral collector-storage passive systems.
Solar Water Heating Systems Solar water heating systems almost always require a backup system for cloudy days and times of increased demand. Conventional storage water heaters usually provide backup and may already be part of a total solar system package. A backup system may also be part of the solar collector, such as rooftop tanks with thermosyphon systems. Since an integral-collector storage system already stores hot water in addition to collecting solar heat, it may be packaged with a demand (tankless or instantaneous) water heater for backup. End of Page
U-Factors Another important consideration is the U-factor. This takes into account the total heat transfer of all the materials, for example, in a wall assembly. The heat has to pass through all the materials as it migrates through the wall. Unlike an R-factor, which measures resistance to heat transfer, the U-factor measures heat transfer. This means that when it comes to U-factors, lower numbers are better. A U-factor is calculated as the reciprocal of an R-factor. Click here for a table of U-factors for common materials.
Sustainable Types of Insulation Sustainable types of insulation include things that are rapidly renewable; examples are wool and cotton. You can shear a sheep and 6 months later, it has re-grown its coat. Likewise, you can harvest cotton and it doesn't take long to grow a new crop. Sustainable insulation is also non-toxic. Again, cotton and wool qualify. Have you ever worked with fiberglass insulation? It can get up your nose and cause your hands and any exposed areas to itch. It can get in your lungs and cause complications. Sustainable insulation is made from natural products such as wool, cotton, and soy-based foam insulation. We are even seeing straw bales used as insulation. Sustainable insulation is made from recycled products such as cellulose insulation made from recycled newspapers. Wool Insulation Wool is natural, renewable, and sustainable. It can absorb moisture without compromising its thermal efficiency. When wool fibers absorb moisture, they generate heat. This warmth acts to prevent condensation in construction cavities by maintaining the temperature above the dew-point in damp conditions. Sheep wool insulation is safe to touch and requires no specialized safety clothing or equipment, making it easy and safe to install. Wool does not support combustion and will extinguish itself in the event of fire. Sheep wool insulation does not settle due to the elasticity of the wool fibers so there is no loss of performance over time. Cotton Insulation Cotton insulation is made from recycled cotton textiles, such as denim. Other benefits of cotton insulation are: it doesn't require any warning labels; no respiratory or other safety equipment is required; it has good acoustical properties and requires little energy to manufacture. Boron, a non-toxic fire and pest resistant treatment, is used as a treatment on the cotton insulation. Unlike fiberglass, there is no formaldehyde off-gassing to be concerned about. Soy-Based Foam Insulation This insulation is sprayed into a house in a liquid form. As it hardens, it expands up to 100 times its size. It fills in all the cracks and spaces inside the walls, making an airtight seal. It is not-toxic and moisture resistant. It resists mold, fungus, and rodents. You can get high R-values in less space than batt insulation. Open-cell type foam insulation is less dense and contains more air space. This is less expensive and will yield about R-3.5 per inch of insulation. Closed-cell type is more dense and heavier. It is more expensive but will yield between R-6.5 and 7.0 per inch. Soy-based foam insulation costs more to install because of the more complicated spraying procedure, but will save considerably in energy bills over time. After a brief check of your understanding, we will turn our attention to ventilation systems. End of Page
Insulated Headers Here's another innovation that utilizes something we talked about earlier - SIPs. This is from toolbase.org. "A Midwestern manufacturer of Engineered Wood Joists has come up with header product that borrows technology from another innovative construction technique-Structural Insulated Panels (SIPs). Superior Wood Systems uses machine stress-rated wood flanges with foam insulation sandwiched between two web panels, to create insulated headers with a thermal break, without sacrificing structural performance. Superior uses two OSB webs that enclose a layer of EPS foam insulation. Along with their engineered joist products, the manufacturer is marketing these headers to builders of conventional framed homes as a strong, lightweight, cost-effective alternative to beam headers. They assert that the headers are straighter and more dimensionally stable, less subject to shrinkage and warping that often causes drywall to crack in conventionally framed header areas. Units are available in 7-¼" 9-¼", and 11-¼" depths, and widths for both 2x4 and 2x6 framing. Thermal losses occur at window and door areas of many homes, but these insulated products can greatly improve the overall energy efficiency of the walls. Superior estimates that the R-value of common double beam headers is about R-7, but that an SWII-62 header (for 2x6 walls) provides an R-value of 18 in a single-piece unit requiring no additional installation labor. The typical home may have several dozen square feet of header area, allowing significant improvement on overall thermal performance."
Tubular Skylights This is one of my favorite products. I have two in my own house and I love them. Read about what toolbase.org has to say. "Many homeowners enjoy the natural lighting that skylights provide. However, skylights often do not distribute light evenly, are a significant source of energy loss, and can cause UV damage to carpets and furniture. Tubular skylights, on the other hand, use the sun for lighting interiors without the drawbacks associated with conventional skylights. They are generally easier to install than typical skylights and, from the home's interior, resemble conventional lighting fixtures. Tubular skylights have a roof-mounted light collector typically consisting of an acrylic lens set in a metal frame. Most have a reflective sun scoop in the rooftop assembly that directs sunlight into a metal or plastic tube which has a highly reflective interior coating. The reflective tube guides the sunlight to a diffuser lens, mounted on the interior ceiling surface, that spreads light evenly throughout the room. The shape of the scoop is generally parabolic to reflect sunlight into the home regardless of the sun's angle in the sky. Some tubular skylights have integrated electrical lights so the fixture can provide light both day and night and some have integrated baffles to regulate the amount of incoming sunlight. The performance of tubular skylights varies widely between brands. Tests performed at the Alberta Research Council indicated that one 13-inch tubular skylight had equivalent light output of up to one 700-watt incandescent bulb in December and one 1,200-watt bulb in June."
For private wells, an acceptable water flow would be about ______ gallons a minute. 1 to 2 -3 TO 4 8 to 9 10 or more
What is the most popular type of water heater today? Tankless Heat pump -STORAGE TANK Solar
A hydronic heating system uses ___________ to heat a home. -HOT WATER Hot air Radiant energy Geothermal energy
Which is not a feature of good plumbing practice? -INSULATE JUST THE HOT WATER SUPPLY PIPES Keep piping runs as short as possible Install shutoff valves on every fixture riser pipe In cold climates, do not run supply pipes in exterior walls and unheated areas
Wells are cased until they reach -BEDROCK Limestone Sand Water
Which type of heating system allows the air to be filtered or moisturized MOST easily? Hot water heat Steam heat -HOT AIR HEAT Radiant heat
What are the two types of solar water heating systems? Conventional and tankless -ACTIVE AND PASSIVE Direct and indirect Flat plate and embedded circuit
Which type of heating system has an expansion tank? -HOT WATER HEAT Electric heat Hot air heat Radiant heat
Amperage Amperage is the total amount of electricity that you have available. In small houses with light loads and perhaps gas appliances, you might be able to get by with 60 amps. 100 amps is a more normal minimum amount. A house with electric heat would require at least 200 amps. It is not unusual today to find large houses with 300 amps or more. Be careful with trying to estimate the amount of amperage that is present in a house. You can read the stated amount on the cover of the electric box or that is stamped on the main cutoff. But that will only definitely tell you the capacity of the main panel box! They may have installed a 200 amp box, for future expansion, and only installed a 125 amp service. Adding up the totals of the amps indicated on each breaker will not be fruitful. Typically more are installed than the total amount because you are not expected to have everything on all at once. If you can't see the entrance cable or don't want to mess with it, don't guess. Don't state the amperage on a listing or an appraisal unless you are sure. You might state that there is a 100-amp service panel box, if you can see that. Don't be fooled by extra boxes and extensions. If there is a 100-amp service entry cable, and then the homeowner added a 40-amp box and another 20-amp box in line, you still only have a 100-amp service. That is all the entry cable can possibly carry. The only definitive way to tell the amperage is to examine the size of the entrance cable. Remember the hose analogy - certain size wires can carry only a prescribed volume of electricity. The size or gauge of the entrance cable will enable you to estimate the amperage of the service.
Wiring - Knob and Tube The earliest type of wiring in a house was called knob and tube. It consisted of bare copper wires strung between porcelain insulators or standoffs. You may still encounter some of these but they are outdated and banned by many codes.
