HVAC Equipment

Manual Damper

GENERALLY CONSISTS OF A SHEET METAL FLAP, SHAPED TO FIT INSIDE THE DUCT. BY ROTATING A HANDLE OUTSIDE THE DUCT, THE TECHNICIAN CAN ADJUST AIR FLOW TO MATCH THE NEEDS OF A PARTICULAR ZONE OR ROOM typically set to control airflow in ducts at the time the system is balanced during initial startup of the system

Motorized Damper

GENERALLY USED IN ZONED SYSTEMS TO AUTOMATICALLY DELIVER CONDITIONED AIR TO SPECIFIC ROOMS OR ZONES

Direct Expansion (DX)

GENERIC TERM USED TO IDENTIFY VAPOR-COMPRESSION REFRIGERATION EQUIPMENT HAVING TWO+ COMPONENTS. ONE IS USUALLY POSITIONED EXTERNALLY AND ONE INTERNALLY

Coil (Cooling)

HAS CHILLED WATER CIRCULATING THROUGH IT SO THE AIRSTREAM IS COOLED, DECREASESE TEMPERATURE AND HUMIDITY LEVELS coils drop below dew point, causing condensation which drips into drip pan Consist of finned coil, copper tubes, and aluminum fins carry chilled water drainage drain pans capture condensation from cooling coil drain pipes allow drainage of condensation pan and/or drain pipes must be checked periodically for blockages

Electric Baseboard Heater

HAVE ELECTRIC RESISTANCE COILS MOUNTED BEHIND SHALLOW PANELS ALONG BASEBOARDS heat is transferred from unit to the room air through convection and radiation each unit has a separate thermostat

Grille

HAVE SETS OF VERTICAL AND HORIZONTAL VANES THAT DEFLECT THE AIR STREAM VERTICALLY AND HORIZONTALLY ALLOWS AIR FROM OCCUPIED SPACES TO ENTER RETURN AIR DUCTWORK sets of vertical and/or horizontal vanes that deflect air stream vertically and horizontally does not have volume control damper (like diffusers and registers) suitable for supply and return air vanes on return air grilles are typically fixed

All-Water (Hydronic) HVAC System

HEAT AND COOL BY CIRCULATING HOT WATER FROM A BOILER OR CHILLED WATER FROM A CHILLER THROUGH A FINNED COIL IN A FAN-COIL UNIT OR UNIT VENTILATOR IN THE SPACE Basic types: steam hot water chilled water Chiller plant (or chiller) plus boiler to produce conditioned (chilled and/or hot) water Includes chiller(s), boiler(s), and room terminal units Conditioned water is pumped to room terminal units (ie. convectors, convector-radiators, chilled beams, etc.) (large building/large application) system components piping/fitting equipment and distribution valves pumps terminal devices (heat/cool emitting) Piping arrangements one pipe two pipe* (two pipe changeover) three pipe* four pipe* water-loop heat pump *these arrangements can be used to deliver hot water and chilled water to AHU in all-air systems one-pipe hydronic series loop have a single pipe that acts as the supply pipe and the return pipe for the flow loop, connecting one terminal unit to the next terminal unit two-pipe hydronic system have a separate supply pipe and return pipe at each terminal unit Two pipe direct return return water from each unit takes shortest path back to boiler with valves in branch lines, each unit can be controlled and serviced separately Two pipe reverse return main flow is in same direction as supply flow offers easier balancing Three pipe systems have a hot-water loop and a cold-water loop so that hot or cold water can be introduced to any terminal unit at any time a single "common" return is used provide both supply heating and chilled water to units hot water, chilled water, common return three way modulating valve at inlet of unit allows hot or cold water depending on load water leaving unit is carried in a common return pipe to either chiller or boiler- inefficient Four Pipe System uses supply and return heating piping and supply and return cooling piping have two separate supply lines (heating and cooling) and two separate return lines (heating and cooling) two coils are used, hot (heating) water and chilled water most commonly used

Energy Efficiency Ratio (EER)

MEASURE OF INSTANTANEOUS ENERGY EFFICIENCY OF COOLING EQUIPMENT PREFERRED RATING cooling-to-electricity, steady-state "efficiency" rating ratio of change in heat at "output" (heat reservoir) to supplied work EER = (cooling output (in BTU/hr) / (electric energy input (in watts) generally calculated using a 95*F outside temp and return air DB temperature of 80*F and 50% RH Higher EER means higher "efficiency"

Seasonal Energy Efficiency Ratio (SEER)

MEASURE OF SEASONAL COOLING EFFICIENCY OF AN ELECTRIC AIR CONDITIONER OR HEAT PUMP USING A STANDARD COOLING LOAD AND OUTDOOR CLIMATE PROFILE OVER A STANDARD COOLING SEASON seasonally-adjusted rating of a heat pump and air conditioner during a full cooling season: SEER = cooling output (in Btu/hr) / (electric energy input (in W) standard measure of refrigeration efficiency higher SEER means higher "efficiency" 8-10 SEER - low-efficiency units (older units only) 13 SEER - medium-efficiency units 14+ SEER - high-efficiency units 18 SEER - super high efficiency units

Chilled Beams

MODERN TERMINAL DEVICES DESIGNED TO BE MOUNTED NEAR OR IN THE CEILING AND HAVE ROOM AIR CIRCULATE THROUGH COILS FED BY CHILLED OR HOT WATER passive chilled beam (all water) active chilled beam (air-water)

Split Air Conditioning System

MOST COMMON TYPE OF CENTRAL AIR CONDITIONING THE CONDENSING UNIT(CONTAINING COMPRESSOR, CONDENSING COIL AND FAN, EXPANSION VALVE) LOCATED OUTSIDE AND A COOLING COIL (EVAPORATOR IN AN AHU OR DUCTWORK NEAR FURNACE) LOCATED INSIDE Evaporator Condensing Unit condenser compressor expansion valve

Heating Seasonal Performance Factor (HSPF)

Measure of 'energy efficiency' of heat pump during a full heating season MEASURE OF THE SEASONAL EFFICIENCY OF AN ELECTRIC HEAT PUMP USING A STANDARD HEATING LOAD AND OUTDOOR CLIMATE PROFILE OVER A STANDARD HEATING SEASON HSPF = (heating output (in Btu/hr)) / (electric energy input (in W)) Higher HSPF means higher efficiency 6.6 and 6.8 HSPF - minimum efficiency single-package and split systems, respectively 7.2-7.8 HSPF - medium efficiency units >8.0 HSPF - high efficiency units Variable speed heat pumps have HSPF ratings up to 10

Coefficient of Performance (COP)

RATIO OF HEAT REMOVED/PROVIDED IN BTU/HR OF ENERGY INPUT Thermodynamic "efficiency" rating ratio of change in heat at "output" (heat reservoir) to supplied work (in Btu/hr or W per W) COP = (cooling output (in Btu/hr)) OR (heating output (in Btu/hr)) / (electric energy input (in Btu/hr)) standard measure of (refrigeration) efficiency higher COP means higher efficiency COP will vary with reservoir temperatures rises as input temperature increases or the output temperature decreases COP decreases when condenser-evaporator temperature difference increases

Variable Air Volume (VAV or VV)

Supply air temperature remains constant Supply air flow rate changes to meet load More complex than CAV tougher to maintain uses less energy due to: lower fan speed (use of variable speed drives) Elimination of reheat capabilities (possible)

Constant Air Volume (CAV or CV)

Supply air flow rate remains constant Supply air temperature is changed to meet load Easier to maintain High energy use due to: constant fan speed (maintains maximum airflow rate) Needs reheat capabilities for better control of multiple zones (rooms)

Cogeneration

Combined heat and power (CHP) use of heat engine or power station to simultaneously generate: electricity useable heat separate heat and power

Upflow Furnace

TAKES IN RETURN AIR FROM THE BOTTOM OF THE CABINET AND DISCHARGES HEATED AIR THROUGH AN OPENING IN THE TOP OF THE CABINET best suited when in the basement supply air is on top of furnace, return air enters the bottom of the furnace. the blower serves both heating and air conditioning mode, airflow direction remains same.

Fan-Coil Unit

USE A FAN TO DISTRIBUTE THE AIR THROUGH THE SPACE. USUALLY CONSISTS OF A HEATING COIL AND/OR COOLING COIL AND FAN ENCLOSED IN A CABINET

Direct Digital Control (DDC) Systems

USE A MICROPROCESSOR-BASED CONTROLLER THAT DIRECTLY CONTROLS EQUIPMENT BASED ON SENSOR INPUT AND SET POINT PARAMETERS. SIGNALS ARE SENT TO A COMPUTER THAT SENDS PREPROGRAMMED SETTINGS. ALLOWS CENTRALIZED BUILDING CONTROL LOCATIONS THROUGHOUT THE BUILDING

Natural Ventilation

USE OF NATURAL AIR TO VENTILATE open windows - used historically uncontrolled ventilation

Central Chilled Water System

USED IN LARGE BUILDINGS CONSIST OF CENTRAL CHILLER TO COOL WATER

DX Dehumidifcation

dehumidification done through a (REFRIGERANT) chemical component rather than water or air based evaporative process

Convector

(CONVECTOR HEATER) IS A HEATING DISTRIBUTION DEVICE THAT IS CONSTRUCTED OF ONE OR MORE FINNED TUBES THAT CARRY STEAM OR HOT WATER AND THAT TRANSFER HEAT BY CIRCULATION OF AIR(NATURAL CONVECTION)

Air-Source Heat Pump

(LIKE A REFRIGERATOR) USES ELECTRICITY TO MOVE HEAT FROM COOL SPACE TO WARM PLACE. OUTSIDE AIR OR WATER IS HEAT SOURCE water-source heat pumps- use water in pond or lake as heat source

Displacement Ventilation

(Underfloor Air Distribution) Low Velocity Displacement Ventilation (LVDL) Fresh cool air is slowly supplied near floor Air rises as it warms Air is exhausted near ceiling Most effective at addressing ventilation loads, not space temperature requirements Uses VAV or CAV system for ventilation and space temperature control Offers: Lower level of pollutants due to stratification Increased ventilation effectiveness Fresh, ventilation air enters breathing zone first 30% less fan energy (with VAV) 15-20% less refrigeration energy Improves ventilation (good IAQ, reduced sick days) Very low sound- increased comprehension (libraries, classrooms) Excellent for direct-indirect evaporative cooling Downside: Few times of year space temperature can't be maintained higher initial cost (typically)

Building Energy Management System (BEMS)

(building automation systems - BAS) CONTROLS ENERGY-CONSUMING EQUIPMENT IN A BUILDING TO MAKE IT OPERATE MORE EFFICIENTLY WHILE MAINTAINING A COMFORTABLE ENVIRONMENT

Expansion Tank

(compression tank) ALLOWS FOR THE EXPANSION OF WATER IN THE SYSTEM AS IT IS HEATED located above the boiler

Horizontal Furnace

(counterflow furnace) LAYS PARALLEL WITH FLOOR OR CEILING MEMBERS. TAKES IN RETURN AIR FROM THE SIDE OF THE CABINET AND DISCHARGES HEATED AIR THROUGH AN OPENING IN THE OPPOSITE SIDE works best in crawl space or attic can be warm air furnace

Vapor Compression Refrigeration Cycle

(direct expansion (DX) refrigeration cycle) METHOD OF TRANSFERRING HEAT FROM A LOW-TEMPEARTIRE REGION TO A TEMPEARTURE REGION, ESSENTIALLY DRIVING HEAT IN A DIRECTION OPPOSITE TO THE DIRECTION IT NATURALLY FLOWS REFRIGERATION/COOLING SEGMENT OF A BUILDING AIR CONDITIONING SYSTEM ABSORBS HEAT FROM WITHIN THE BUILDING AND TRANSFERS IT OUTSIDE LIKE A REFRIGERATOR THAT TAKES HEAT FROM THE ICEBOX AND PUSHES IT OUT TO COOL IT VCR cycle uses a circulating refrigerant (liquid/gas) as heat transfer medium refrigerant absorbs/removes heat from space to be cooled and rejects heat elsewhere used in air conditioners, refrigerators, freezers, etc. Operation Principles (compression) gases are compressible gases get hot when compressed; cool when expanded (Heat flow) heat flows from high temperature region to low (Fluid (gases and liquids) flow) fluids flow from high pressure to low Refrigerant Principles physical principles related to a refrigerant: heat moves from high to low temperature region change in pressure (in fluids) is proportional to change in temperature pressure increase <-> temp increases pressure decrease <-> temp decreases a phase change results in absorption/release of 'more' latent heat

Fitting

A COUPLING, TEE, ELBOW, OR SIMILAR DUCT SECTION THAT CHANGES THE DIRECTION OF AIRFLOW OR CHANGES THE SIZE OR SHAPE OF THE DUCT (transition)

Central Air Conditioner

A DX REFRIGERATION COOLING SYSTEM. 4 BASIC PARTS CONDENSING UNIT(COMPRESSOR, CONDESNSER, EXPANSION VALVE) COOLING COIL (EVAPORAROR IN AHU OR DUCTWORK NEAR FURNACE) DUCTOWRK (DISTRIBUTION) CONTROL MECHANISM (THERMOSTAT)

Centrifugal Fan (squirrel cage fan)

A FAN IN WHICH THE AIR IS TURNED FROM PARALLEL TO THE AXIS OF ROTATION ON ENTRY TO A DIRECTION TANGENTIAL TO THE ARC DESCRIBED BY THE TIPS OF THE ROTATING BLADE OR VANES air turns 90 degrees as it travels from inlet to outlet most common supply fan backward-curved fans are most efficient

Register

A GRILLE EQUIPPED WITH A BUILT IN DAMPER ALLOW CONDITIONED AIR FROM SUPPLY AIR DUCTWOKR TO ENTER THE OCCUPIED SPACE FLOOR BASED similar to diffusers designed and used for floor or sidewall air supply types adjustable-blade single deflection fixed-blade 2-way throw high-velocity slot adjustable-blade double deflection

Convector Radiator

A HEATING DISTRIBUTION DEVICE THAT TRANSFERS HEAT FROM STEAM OR HOT WATER BY RADIATION AND CONVECTION HOT WATER OR STEAM RUNS THROUGH A PIPE CORE, HEATING METAL PLATES OR FINS ATTACHED TO IT AT SHORT INTERVALS

Radiator

A HEATING DISTRIBUTION DEVICE THAT TRANSFERS HEAT FROM STEAM OR HOT WATER BY RADIATION TO OBJECTS WITHIN VISIBLE RANGE AND BY CONDUCTION TO THE SURROUNDING AIR THAT IS CIRCULATED BY NATURAL CONVECTION freestanding fixture typically made of formed steel or cast iron. usually visibly exposed within the room or space to be heated

Duct

A HOLLOW PIPE OR CONDUIT THAT CONVEYS AND TRANSFERS AIR IN AN HVAC SYSTEM ductwork duct fittings sheet metal rectangular duct galvanized steel sheet metal sheet metal box-like sections most commonly used low height (offers more headroom) sheet metal round (spiral) duct most efficient shape -- lower static pressure loss less expensive than rectangular duct easy to install taller than rectangular duct (offers less headroom) less turbulence/sound sheet metal oval (spiral) duct efficient shape - lower static pressure loss height similar to rectangular more expensive than rectangular flexible duct can be metallic or nonmetallic adverse effects on system performance (increased resistance to flow - very high static pressure loss): routing/length of flexible duct degrees of each bend sag between support joints Fabric (textile) duct air-permeable woven polyester cloth-fabric great diffusion - provides low velocity, uniformly distributed air less installation time than sheet metal ducts economical Duct Board available in 1 and 1.5 inch thickness resin-bonded glass fibers with reinforced, foil-laminante, air-barrier, vapor-retardant facing Joist Bay Duct a joist bay used to transport return air called "panning" Ductwork optimization small ducts reduce ducting costs (less material) save building space (typically headroom) larger ducts reduce velocity and pressure drop (lower noise) doubling duct diameter = quadrupling air flow area lower fan energy doubling duct diameter reduces fan horsepower (BY A FACTOR OF 32) Turning Vanes creates uniform airflow reduces pressure loss and reduces need for fan horsepower reduces noise Duct Leakage/Sealing leakage testing simple devices consisting of a variable speed fan - provides pressurization of ductwork calibrated orifice plates - used to measure fan's airflow Duct (thermal) insulation insulation required for supply ducts when: duct inside-outside temperature difference exceeds 15*F (8*C) ducts are located outside of building envelope not needed for: exhaust air ducts ducts located within equipment Duct Lining 1-2 inches thick used for acoustical control

Fan

A MECHANICAL DEVICE THAT USES ROTATING AIRFOIL BLADES OR VANES TO CONTINUOUSLY MOVE AIR

Evaporator

A NETWORK OF TUBES FILLED WITH REFRIGERANT LOCATED INSIDE THE BUILDING THAT ABSORBS HEAT FROM AIR OR LIQUID AND MOVES IT OUTSIDE THE REFRIGERATED AREA BY MEANS OF A REFRIGERANT helps to cool a space INSIDE

Condenser

A NETWORK OF TUBES THAT DISCHARGES UNWANTED HEAT FROM THE REFRIGERANT TO A MEDIUM (AIR/WATER)THAT ABSORBS HEAT, as heat is discharged, refrigerant condenses and becomes liquid again LOCATED OUTSIDE COOLS

Induced-Draft Furnace

A NONCONDENSING FURNACE IN WHICH A MOTOR-DRIVEN FAN DRAWS AIR FROM THE SURROUNDING AREA OR FROM OUTDOORS TO SUPPORT COMBUSTION also called fan-assisted combustion, forced-draft, power-burner, power-combustion, and pressure-fired furnace

Natural-Draft Furnace

A NONCONDENSING FURNACE IN WHICH THE NATURAL FLOW OF AIR FROM AROUND THE FURNACE PROVIDES THE AIR TO SUPPORT COMBUSTION

Compresser

A PUMP-LIKE DEVICE THAT DRIVES THE REFRIGERANT FROM THE INDOOR EVAPORATOR TO THE OUTDOOR CONDENSER AND BACK TO THE EVAPORATOR AGAIN - INCREASES PRESSURE/TEMP OF REFRIGERANT "HEART" OF SYSTEM BECAUSE IT CIRCULATES THE REFRIGERANT

Louver

A SHUTTER-LIKE DEVICE WITH FIXED SLATS OR VANES THAT ARE ANGLED TO ADMIT OR RELEASE AIR, TO PROVIDE PRIVACY AND TO KEEP OUT RAIN AND NOISE Fans axial or vane-axial fan centrifugal fan (squirrel cage fan) propeller fan

Evaporative Cooler (Swamp Cooler)

A TYPE OF COOLING DEVICE THAT TURNED INCOMING DRY, HOT OUTDOOR AIR INTO MOIST, COOL AIR BY SATURATING THE AIR WITH WATER reduces temp by 30-40 degrees as it is drawn through WET PADS and blown into building 3 types, single-stage direct coolers; indirect evaporative cooling; and, two-stage, direct/indirect coolers Air in contact with water evaporates water Air is cooled to ~wet bulb temperature ADVANTAGE efficient cooling at low cost DISADVANTAGE supply air is moisture rich - high humidity ratio and relative humidity

Unit Ventilator

A TYPE OF FAN-COIL UNIT THAT HAS THE CAPACITY TO INTRODUCE VENTILATION (OUTDOOR) AIR INTO A ROOM IN ADDITION TO BEING ABLE TO PROVIDE SPACE COOLING AND/OR HEATING must have thermostatic controls condensates

Induction Unit

A TYPE OF FAN-COIL UNIT THAT RECEIVES PRIMARY AIR FROM A CENTRAL AIR-HANDLING UNIT, WHICH INCLUDES VENTILATION (OUTDOOR) AIR no fan

Heat Pump

A TYPE OF HEATING AND/OR COOLING DEVICE THAT DRAWS HEAT INTO A BUILDING FROM OUTSIDE DURING THE HEATING SEASON if cooling capable, heat pump expels heat from the building during cooling season heat pumps that provide heating and cooling capabilities are like air conditioners except they include reversing valve with a different refrigerant circuit design for the refrigerant metering device direct expansion systems whose in-door-outdoor coils are used reversibly as condensers or evaporators depending on the need for heating or cooling Operates on VCR (refrigeration) cycle Can heat and cool Reverses the AC cycle to provide indoor heating temperature limitations exist (outdoors) Types air source (air to air) geothermal earth/ground coupled lake coupled well coupled

Thermal Zoning

A WAY OF DIVIDING A BUILDING INTO INDEPENDENT AREAS WITH SIMILAR HEATING AND COOLING NEEDS Physical spaces within building that has its own thermostat and distribution system for maintaining thermal comfort individual/neighboring indoor spaces with similar thermal loads reduces number of HVAC systems Types interior/perimeter one system- separate zones with terminal boxes

Return Air

AIR FROM THE CONDITIONED BUILDING SPACES THAT IS RETURNING TO THE AHU, WHICH RECONDITIONS THE AIR. SOME RETURN AIR IS EXHAUSTED

Variable Air Volume (VAV or VV) Distribution System

AIR HANDLING CONFIGURATION THAT HOLDS SUPPLY AIR TO A CONSTANT TEMPERATURE AND CONTROLS TEMPERATURE WITHIN A SPACE BY VARYING THE QUANTITY OF SUPPLY AIR REFERRED TO AS VARIABLE VOLUME CONSTANT TEMPERATURE SYSTEMS (VVCT) single-duct VAV system dual- duct VAV system

Constant Air Volume (CAV or CV) Distribution System

AIR-HANDLING CONFIGURATION THAT PROVIDES STEADY AIRFLOW INTO A ROOM OR GROUP OF ROOMS WHILE VARYING THE TEMPERATURE OF THE AIR TO MEET HEATING AND COOLING DEMANDS single duct CAV systems dual duct CAV systems (heating and cooling) Single-zone CAV systems (one zone) multi-zone CAV systems terminal reheat (CVTR) systems (multiple zones) single duct-single zone single zone system- one thermostat controls several rooms in a single thermal zone simple system uneven comfort for multiple rooms good for applications requiring air filtration and humidity control single duct-terminal reheat modification of single zone system incorporates a reheat coil at each zone - for individual temperature control responds to space conditions of each zone energy efficiency is poor single duct-multi-zone modification of single duct system two separate ducts: heating and cooling Responds to multizone conditions Hot deck temp is determined by outdoor thermostat Cold deck is maintained at 55*F Zone air is mixed by zone mixing dampers located within main plenum One supply duct to each zone Dual Duct System Responds to unlimited number of zones or condition spaces - one thermostat controls mixing box for each room Fan arrangements: hot deck/cold deck Terminal mixing boxes located at each zone Most expensive type of system

Damper

AN AIRFLOW CONTROL DEVICE USED IN DUCTWORK TO VARY THE VOLUME OF AIR PASSING THROUGH AN AIR OUTLET, AIR INLET, OR DUCT OPENS AND CLOSES TO CONTROL AIRFLOW designed to regulate air volume (flow) manually adjusted dampers automatic dampers single-blade dampers multi-blade dampers fire dampers smoke dampers

Furnace/Warm Air Furnace

AN APPLIANCE WITH AN ENCLOSED CHAMBER WHERE FUEL IS BURNED OR ELECTRICAL RESISTANCE HEATING IS USED TO HEAT AIR DIRECTLY forced air furnaces have a fan within the unit

Electric Boiler

AN ELECTRODE OR ELECTRICAL RESISTANCE HEATING HEATS WATER separate classification because they are not heated with combustion of a fuel and no flue opening is needed

Fire Damper

AUTOMATICALLY CLOSE TO OBSTRUCT SMOKE AND FIRE FROM A BUILDING BLAZE. INSTALLED ON PLANE OF FIREWALL UPON DETECTION OF HEAT, THE FUSIBLE LINK MELTS, CLOSING THE DAMPER closes automatically upon detection of heat standard rating: 165*F other ratings: 212*F and 285*F protects integrity of fire barrier (wall or ceiling/floor) maintains wall fire resistance rating where penetrated by HVAC ductwork or equipment failure to close fully may lead to catastrophic (loss and property) accordion (curtain) fire damper

Unit Heater

CAN BE A TYPE OF INDIVIDUAL FORCED-AIR HEATER THAT IS SUSPENDED FROM THE CEILING OR HUNG FROM A WALL. BUILT IN FAN THROWS AIR DIRECTLY INTO THE SPACE WHERE THE HEATER IS SITUATED. operates like a furnace without the ductwork

Air Filter

CLEANS THE AIR OF UNDESIRABLE ELEMENTS sound attenuating filters-reduce level of sound moving through ductwork

Smoke Damper

CLOSES UPON DETECTION OF SMOKE, PREVENTING THE CIRCULATION OF AIR AND SMOKE THROUGH A DUCT OR A VENTILATION OPENING

Demand-Controlled Ventilation (DCV)

CO2 sensors used occupant controlled ventilation is automatic adjustment of ventilation equipment according to occupant choice. DCV is a control method that modulates the volume exchange of fresh or outside air into an enclosed space by mechanical air conditioning equipment.

Coil (Heating)

COILS THAT CARRY HOT WATER OR STEAM WHICH HEATS THE AIRSTREAM BEFORE THE AIR IS DISTRIBUTED FOR SPACE HEATING Consist of finned coil, copper tubes, and aluminum fins carry hot water

Coil (DX)

COILS THAT CARRY REFRIGERANT

Fan Filter Unit (FFU)

COMBINES A FILTER(S) AND A FAN(S) IN AN AHU

Steady State Efficiency

COMPUTED BY MEASURING ENERGY INPUT MINUS EXHAUST (VENT AND CONDENSATE) LOSSES DIVIDED BY ENERGY INPUT (ENERGY INPUT - EXHAUST LOSS)/ENERGY INPUT

Supply Air

CONDITIONED AIR FROM THE AHU INTRODUCED TO OCCUPIED SPACES

Infrared Heater

CONSIST OF A HOT SURFACE THAT RADIATES HEAT ENERGY IN A SPECIFIC DIRECTION radiated energy warms floors and other objects in the space. little energy lost to air because it is poor absorber

Air-Water HVAC System

CONSISTS OF AN AIR SIDE AND A WATER SIDE, WHICH CONTRIBUTES TO HEATING, COOLING, AND VENTILATION Heating/cooling delivered via local equipment Have an air side and a water side Includes chiller(s), boiler, and room terminal units with ventilation Delivers a combination of heated/cooled air and hot/chilled water to space (Large building/large application) Advantages: individual room control allows independent heating and cooling fair reliability - only single zone affected by malfunction low initial cost Disadvantages short life noise within space poor humidity control, air filtration, and ventilation

Multiblade Damper

CONSTRUCTED OF A NUMBER OF BLADES (OR SHUTTERS) CONFIGURED IN A PARALLEL OR OPPOSED BLADE CONFIGURATION parallel-bladed dampers opposed-bladed dampers

Fire Tube Boiler

CONSTRUCTED OF A VESSEL THAT HOLDS WATER AND HAS HOLLOW PASSAGES (TUBES) WITHIN THE VESSEL THAT ARE SURROUNDED BY THE WATER. HOT COMBUSTION GASES FROM THE BURNING FUEL PASS THROUGH THE INSIDE OF THE TUBES, DRIVING HEAT TO THE WATER. tubes may be arranged horizontally or vertically above combustion area high storage of heat energy

Opposed-Blade Damper

CONTROLS AIRFLOW (SLOWS)

Chilled Water System

COOLS WATER AT A CENTRAL POINT, IN A CONDENSER, THEN DISTRIBUTES CHILLED WATER THROUGHOUT THE BUILDING LARGE BUILDINGS A central cooling system (components) chiller condenser (ie. cooling tower, air-cooled condenser) air handling unit (AHU) chilled water pumps condenser water pumps potential equipment being served by system: fan-coil units unit ventilators chilled beams chilled sails air handling units

Chilled Water

COOLS WATER WHICH IS USED TO REMOVE HEAT FROM THE BUILDING

Boiler Horsepower (BHP)

DEFINED AS THE EVAPORATION OF 34.5 POUNDS OF WATER INTO STEAM AT 212*F AT STANDARD ATMOSPHERIC PRESSURE type of gross output rating ONE BHP = 33475 Btu/hr = 9.81 kW

Volume Control Damper

DESIGNED TO CONTROL AIR FLOW IN A HVAC SYSTEM

Mixed-Air Ventilation

Dilution Ventilation (Overhead Air Distribution) Air is introduced at a high (ceiling) level Air mixes and dilutes contaminants Whole volume of space is conditioned/ventilated Most effective at addressing space temperature requirements (not ventilation loads) Requires "well mixed" design Less efficient ventilation (air "short circuiting") Re-circulates diluted pollutants

Cooling Coil

EVAPORATOR

Reheat (RH) Terminal Box

FACTORY-MADE ASSEMBLY THAT HAS HOT WATER OR STEAM REHEAT COILS OR ELECTRIC-RESISTANT HEATERS WITHIN THE BOX CAN INCREASE TEMPERATURE OF AIRSTREAM BY REHEATING IT BEFORE IT ENTERS A SPACE THAT DOES NOT NEED THE DESIRED COOLING

Terminal Box

FACTORY-MADE ASSEMBLY THAT IS PART OF THE DUCT SYSTEM THAT MANUALLY OR AUTOMATICALLY CONTROLS VELOCITY, PRESSURE, HUMIDITY, AND/OR TEMPERATURE OF THE SUPPLY AIR BY CONTROLLING MIXING OF AIR AND/OR AIRFLOW RATE Interact with zone thermostat control supply airflow entering zone control supply air temperature constant volume (CV) terminal box variable air volume (VAV) terminal box reheat (RH) terminal box

Constant Volume (CAV or CV) Terminal Box

FACTORY-MADE ASSEMBLY THAT USES SPECIAL DESIGN AND CONSTRUCTION FEATURES THAT PROVIDE UNUSUALLY QUIET OPERATION sound attenuating chamber

Variable Air Volume (VAV or VV) Terminal Box

FACTORY-MADE ASSEMBLY WITH A FAN ADDED TO RECIRCULATE PLENUM AIR FOR HEATING ONLY Damper closes to warm the space, cool air supply is reduced damper opens to cool the space, cool air supply is increased VAV terminal boxes can throttle airflow from 100% to 0% of design flow most VAV terminal boxes have a minimum flow settling to maintain ventilation levels

All-Air HVAC System

HEAT, COOL, VENTILATE BY PROVIDING AIR ONLY TO THE SPACE BEING CONDITIONED Cooled/heated air from central plant/AHU via ducting Includes chiller(s), boiler(s), AHUs, terminal boxes AHUs deliver heated/cooled air to space through ductwork Advantages heating/cooling delivered via air only allows good temperature and humidity control good humidification and heat recovery allows for complex zoning can use outside air for economizer cycle Disadvantages special care for maintenance access greater volume of equipment space needed supplemental perimeter radiation may be needed Types Constant Air volume (CAV or CV) single zone terminal reheat multizone dual duct Variable Air Volume (VAV or VV) Variable Volume Variable Temperature (VV-VT) (Large building/large application) supply air ducts supply (conditioned) are from AHU to diffusers/registers introduces supply air to occupied space return air ducts removes air from building spaces returns air to air-handling unit, which reconditions some air some air is exhausted Exhaust Air ducts return air exhausted to building exterior Outdoor air ducts supplies outdoor air to air-handling unit Used for ventilating occupied building spaces Mixed Air Duct mixed outdoor air and return air in chamber supplies mixed air to air-handling unit Extended plenum supply Individual Supply system Perimeter-loop system Trunk duct - 2 way Trunk Duct - 1 way Full Exhaust- 100% Outside Air no return air because the return air may contain contaminants Mixed Air outside air is combined with return air

Water Tube Boiler

HOLDS WATER IN SMALL TUBES THAT ALLOWS HOT COMBUSTION GASES TO PASS OVER THE TUBES WHERE THE BOILER WATER IS CONTAINED smaller diameter tubes, more surface area very sensitive to demands

Circulator/Circulating Pump

HOT WATER IS CIRCULATED FROM THE BOILER THROUGH THE PIPES AND BACK TO THE BOILER BY A PUMP. THE PUMP PROVIDES FAST DISTRIBUTION OF HOT WATER THROUGH THE SYSTEM, THUS DELIVERING HEAT AS QUICKLY AS POSSIBLE. size based on delivery of water required

Heating Coil

HOT WATER OR STEAM IS CIRCULATED THROUGH A HEATING COIL SO IT HEATS THE AIRSTREAM BEFORE THE AIR IS DISTRIBUTED FOR SPACE HEATING

Parallel-Blade Dampers

IMPART A DIRECTIONAL CHARACTERISTIC TO THE AIRFLOW THAT DIRECTS THE AIR STREAMS INTO EACH OTHER. PROMOTE MIXING OF AIR STREAMS

Economizer

IN AN AHU USES COOL OUTSIDE AIR TO COOL INSIDE AIR (cycle) free cooling source: when available, uses cool outdoor air instead of mechanically cooled air normal operation outside air dampers are positioned to provide the minimum required outside air economizer operation when outside air is 'cool', outside air dampers are fully opened. maximum outside air is provided.

Interior/Central Thermal Zones

INCLUDES ROOMS AND SPACES THAT ARE CORE SPACES THAT HAVE NO EXTERIOR WALLS HEAT GENERATED BY LIGHTS, OCCUPANTS, AND OFFICE EQUIPMENT DOMINATE THE LOAD, WHICH IN MOST SITUATIONS PROVIDES CONTINUOUS COOLING DEMAND

Perimeter Thermal Zone

INCLUDES ROOMS AND SPACES WITH AT LEAST ONE EXTERIOR WALL. LOADS VARY OVER BROAD RANGE FROM HEATING TO COOLING AND ARE AFFECTED BY BOTH INTERIOR AND EXTERIOR FACTORS

Water-Loop Heat Pump (WLHP) System

INDIVIDUAL PACKAGED WATER SOURCE HEAT PUMPS ARE LOCATED IN EACH BUILDING ZONE AND OPERATE TO MEET THE HEATING OR COOLING LOAD IN THAT ZONE In space needing cooling, heat pump extracts heat from room air and rejects heat to water loop In space needing heating, heat pump extracts heat from water loop Used where there is a simultaneous call for heating and cooling throughout much of the year

Desiccant Dehumidification

INVOLVES THE USE OF CHEMICAL OR PHYSICAL ABSORPTION OF WATER VAPOR TO DEHUMIDIFY AIR AND REDUCE THE LATENT COOLING LOAD IN A BUILDING HVAC SYSTEM improves indoor air quality by preventing condensation in equipment and reducing the propogation of microbiologicals that can contaminate indoor air DESICCANT is a drying substance or agent

Cooling Tower

LARGE SCALE EXPELS HEAT FROM CHILLED WATER SYSTEM WHEN WATER IS COOLED BY DIRECTLY OR INDIRECTLY CONTACTING THE ATMOSPHERE increase water use, extensive maintenance requirements, require freeze protection, close control of water treatment to function successfully

Refrigerant

LIKE WATER - expands when freezes, condenses when a liquid and warmer A SUBSTANCE THAT PRODUCES A REFRIGERATING EFFECT WHILE EXPANDING OR VAPORIZING AS IT CIRCULATES AS A GAS OR LIQUID THROUGH A CLOSED VAPOR-COMPRESSION REFRIGERATION SYSTEM picks up heat by evaporating at a LOW TEMPERATURE AND PRESSURE and gives up heat by condensing at a HIGHER TEMPERATURE AND PRESSURE

Reheat (RH) Coil

LOCATED IN DUCTS NEAR SPACE BEING CONDITIONED AND ARE USED TO RAISE TEMPERATURE OF CIRCULATED AIR AFTER IT WAS OVERCOOLED TO REMOVE MOISTURE

Filter (Air)

Mechanical filters captures particles ranging of 0.1 - 100 microns may create pressure drop problems new generation- incorporates synthetic materials that carry a charge to attract and hold particles Electronic air cleaners effectively separate out particulate matter from air for small air volumes large air volumes require multiple units, which consumes large amounts of energy Sound attenuating Filters used to attenuate airborne noise through ductwork systems, ventilating fans. and other equipment active duct attenuators operate electronically (microprocessors, loudspeakers and microphones) Carbon Filter activates carbon-filtering medium is a porous material that can absorb volatile chemicals on a molecular level removes most odors, gases, smoke, and smog from the air by means of an absorption process carbon-filtering does not remove larger particles High-efficiency particulate air (HEPA) filters are often impractical in central HVAC systems due to large pressure drop caused by the dense filter material used Filter replacement Determined by pressure drop across filter checked with an electronic manometer- determines if a filter is clogged (and if filter replacement is needed)

Night Flush Ventilation/Night Ventilation Precooling

OPERATING THE BUILDING MECHANICAL COOLING SYSTEM TO CIRCULATE OUTDOOR AIR INTO THE SPACE DURING THE NATURALLY COOLER NIGHTTIME HOURS

Mixed Air

OUTDOOR AIR AND RETURN AIR MIXED IN THE AHU THAT TURNS INTO SUPPLY AIR

Outdoor Air

OUTDOOR AIR IS USED FOR VENTILATION THE OCCUPIED BUILDING SPACES

Roof Top Unit (RTU)

PACKAGED HEATING AND/OR COOLING UNIT THAT CONDITIONS A STRUCTURE unitary systems manufactured in various configurations providing single or multi-zone heating, cooling, and ventilation cooling only cooling with gas heat cooling with electric heat 1 - 150 tons of cooling capacity <100 to 1500 MBH heating capacity

Evaporative Condenser

PASS AIR OVER COILS SPRAYED WITH WATER, TAKING ADVANTAGE OF THE LATENT HEAT OF VAPORIZATION TO REDUCE THE CONDENSER TEMPERATURE

Air-Cooled Condenser

PASS OUTDOOR AIR OVER A DRY SURFACE COIL TO CONDENSE REFRIGERANT CONTAINED INSIDE THE COIL RESULTS IN HIGHER CONDENSING TEMP AND LOWER PERFORMANCE UNDER PEAK CONDITIONS COMPARED TO WATER COOLED CONDENSERS

Humidifier

PIECE OF EQUIPMENT THAT ADDS WATER VAPOR TO THE AIR IN A BUILDING TO INCREASE RELATIVE HUMIDITY device/equipment that increases humidity of air types of humidification atomization vaporization evaporation adding moisture to air without changing its dry bulb temperature move vertically upward along dry bulb temperature line residential humidifiers pan-type humidifiers electrically heated humidifiers wetted media humidifiers fan-type humidifier bypass humidifiers duct-mounted humidifiers atomizing humidifiers commercial humidification systems spray atomization systems steam injection systems direct steam injection steam-to-steam heat exchanger injection gas-fired steam injection disposable electrode steam generator small commercial: wetted media humidification performance uses: libraries/museums computer rooms greenhouses printing plants pharmaceutical plants output rates in: lb/hr (kg/hr) lb/day (kg/day) outputs up to ~3000 lb/hr (~1360 kg/hr)

Air Handing Unit (AHU)

PREASSEMBLED OR SITE BUILT EQUIPMENT DEVICE CONTAINING COILS AND FANS THAT IS USED TO CONDITION AND CIRCULATE AIR AS PART OF AN HVAC SYSTEM made up of fan(s), cooling and heating coils, dampers, and filters delivers air to supply air ductwork that conveys conditioned air into zones (rooms) often integrated ventilation operation heating and cooling coils to condition air dampers control flow outside air return air mixed air supply (conditioned) air air filter(s) removes dust particles from air fans move air and deliver conditioned air to building

Chiller

PRODUCES CHILLED WATER cooling machines that make chilled water mechanical (VCR) chillers (use vapor-compression refrigeration process to chill water) centrifugal chillers (large capacities) screw chillers (medium capacities) scroll chillers (smaller capacities) reciprocating chillers (smaller capacities; older) Absorption (thermal) chillers direct-fired absorption chillers indirect-fired absorption chillers absorption chillers chilled water machines use thermal energy to chill water consume energy from excess steam excess process (hot) water natural gas, oil, or kerosene solar energy larger chillers are more efficient chillers are more efficient at full load; less efficient at partial load central chiller components (Evaporator) refrigerant-to-water, shell-and-tube heat exchanger typically water in tubes, refrigerant on shell-side usually designed for constant water flow (Condenser) - discharge heat (outdoor air) to atmosphere Air cooled type fin-tube heat exchanger multiple fans for capacity control water cooled type (evaporative condensers) shell and tube heat exchanger cooling tower used for cooling water or other working medium, discharges heat to atmosphere water in contact with air evaporates; water is cooled to WB temp of air

Axial-Flow Fan

PROPELLER TYPE FANS THAT USE A PROPELLER TO DRAW AIR INTO THE FAN AND DISCHARGE IT IN THE SAME AXIAL DIRECTION Typical indoor residential fans used to circulate air

CO2 Sensor

PROVIDES OCCUPANCY-BASED VENTILATION CONTROL provides CO2 level sensing used for demand control ventilation (DCV)

Condensing Furnace

RECOVER WASTE HEAT FROM THEIR EXHAUST GASES THAT WOULD OTHERWISE BE LOST TO THE ATMOSPHERE heat exchange furnace Differ from conventional furnaces achieved through enlarged heat exchanger surface, which extracts sensible heat and extracts latent heat from the water vapor generated during combustion can use plastic piping because its not hot

Dehumidifier

REMOVES MOISTURE FROM AIR BY CHEMICAL OR PHYSICAL METHODS reduces level of humidity in the air removing moisture to air without changing its dry bulb temperature move vertically downward along dry bulb temperature line

Geothermal Heat Pump

RENEWABLE ENERGY THAT USES NATURAL HEAT STORAGE ABILITY OF THE EARTH/GROUNDWATER TO HEAT/COOL A BUILDING Heat pump system coupled with earth (ground or water) uses earth as a heat sink soil temperature change seasonal soil temperature change as a function of depth below ground surface for an average moist soil GHP system components (ground (heat exchange) loop) system of fluid-filled plastic pipes near building ground coupled (buried in ground) submersed in body of water connected to water source (open loop) (heat pump) for heating: HP removes heat from fluid in pipes, concentrates it, and transfers it to building as heat for cooling: process is reversed: heat is transferred from building to earth (air delivery system) conventional ductwork attached to heat pump heated/cooled air distribution to building spaces

Net Rating

REPRESENTS THE NET CONNECTED DESIGN LOAD THAT CAN BE SUPPLIED WITH HEAT BY A BOILER OF A GIVEN OUTPUT, ALLOWING FOR NORMAL PIPING LOSSES AND PICKUP FROM A COLD START MBH, kW, square feet of radiation

Exhaust (relief) Air

RETURN AIR THAT IS DISCHARGED TO THE OUTDOORS

Relief Valve

SAFETY DEVICE ON A SEALED SYSTEM. OPENS TO RELIEVE PRESSURE WHEN BUILT UP TOO HIGH

Integrated Part-Load Value (IPLV)

SEASONAL EFFICIENCY RATING METHOD BASED ON REPRESENTATIVE ANNUAL COMMERCIAL LOADS seasonal efficiency rating method based on representative annual commercial (non-residential) loads IPLV = (cooling output (in BTU/hr)) / (electric energy input (in W)) Higher IPLV means higher efficiency applies to chillers, cooling units and heat pumps with cooling capacities equal to or greater than 65,000 Btu/hr Determined under a variety of conditions - when unit is operating at 25%, 50%, 75% and 100% of capacity and at different temperatures

Packaged-Terminal Air-Conditioning (PTAC) Unit

SELF-CONTAINED, AIR COOLED DX COOLING UNIT self-contained through-the-wall air conditioning (or heat pump) unit LIKE MADELINES wall-split air conditioning systems or ductless systems supplies chilled (or heated) air to a single room of building can use refrigerant as cooling and heating medium offers smaller size and flexibility for zoning used in hotels, motels, senior housing, hospitals, condominiums, apartment buildings, add-on rooms, and sunrooms

Downflow Furnace

TAKES IN RETURN AIR FROM THE TOP OF THE CABINET AND DISCHARGES HEATED AIR THROUGH AN OPENING IN THE BOTTOM OF THE CABINET best suited for application where ductwork is positioned below the furnace such as an upper story closet or in an attic space. A/C evaporator coil is mounted on bottom of furnace inside plenum which distributes supply air. Return air enters through top of furnace.

Diffuser

THE SUPPLY OUTLETS OF AN DUCT WITH BUILT-IN LOUVERS OR DEFLECTION DEVICES THAT THROW AND DISPERSE AIR TO PROMOTE GOOD AIR CIRCULATION AND TEMPERATURE EQUALIZATION IN CONDITIONED SPACES ALLOW CONDITIONED AIR FROM SUPPLY AIR DUCTWORK TO ENTER THE OCCUPIED SPACE CEILING quietly delivers air for: conditioning ventilating evenly distributes flow of air in desired directions without causing drafts enhances mixing of room air Ceiling Diffusers Slot Diffusers Floor Diffusers Coanda effect tendency of fluid jet to stay attached to adjacent surface used to increase throw of ceiling and wall-mounted diffusers diffuser throw diffuser creates low-velocity air movement in occupied area (<50 fpm (0.25 m/s)) low pressure drop manufacturers report THROW - distance until velocity is reduced to specified level

Heating, Ventilation, and Air Conditioning (HVAC)

THE SYSTEM(S) THAT CONDITION AIR IN A BUILDING Heating adding heat Ventilating intentionally introducing outdoor air by mechanical (or forced) methods Air-Conditioning THE PROCESS THAT INVOLVES HEATING, COOLING, HUMIDIFYING, AND CLEANING AIR cooling/refrigerating - removing heat humidifying - adding moisture dehumidifying - removing moisture filtering/cleaning - removing contaminants (technically, also can include heating) Equipment (space heating) USED FOR HEATING AIR IN BUILDING SPACES boilers furnaces rooftop units (RTUs) infrared heaters (space cooling) USED FOR COOLING AIR IN BUILDING SPACES refrigeration central air split systems chillers and cooling towers rooftop units (RTUs) evaporative coolers (ventilation equipment) (humidification/dehumidification) Distribution (secondary) (Air-side Components) ductwork dampers air handling units fans terminal units diffusers, registers, grilles (Water-side Components) piping pumps expansion tanks heat exchangers valves terminal units Deposits and Corrosion boiler scale/deposits form when impurities precipitate on hot boiler tubes/other surfaces pitting (corrosion) can cause tube/material failure (boiler shutdown) use of more fuel reduction of equipment life

Gross Output Rating

TOTAL AMOUNT OF HEAT AVAILABLE AT THE BOILER OUTLET FOR A SPECIFIED FUEL INPUT Expressed in thousands of Btu per hr (MBH), boiler-horsepower (BHP), pounds of steam per hour electric in kilowatts (kW) (SI Units)

Sectional Boiler

TYPE OF FIRE TUBE BOILER in most original boiler rooms, there was no convenient way to replace boilers because of small spaces so the sectional boiler can be taken in pieces and assembled on site low initial cost, high labor cost small steaming areas so they are very sensitive to changes in demand or water levels

Thermostat

TYPICALLY CONTROLS THE FURNACE VAVLE OR BURNER CONTROLS FLOW OF FUEL, ALLOWING FUEL FLOW WHEN THERMOSTAT CALLS FOR HEAT - FAN SWITCH CONTROL FAN temperature sensors provides air temperature sensing manual programmable optimum start (outdoor temperature sensor)

Ice Thermal Storage

USES THE LATENT HEAT OF FUSION OF WATER (144 BTU/LB * DEGREE F) TO STORE COOLING CAPACITY ICE IS STORED AND WHEN COOLING IS NEEDED WATER IS CIRCULATED THROUGH THE ICE STORAGE AREA THEN DISTRIBUTED AT 34*F TO PRIVIDE SPACE COOLING partial-storage strategy load-leveling demand-limiting full-storage strategy helps level out need for cooling during peak hours

Heat Recovery Ventilation (HRV)

USING EXISTING HEAT CONTAINING AIR THAT IS BEING EXPELLED FROM THE BUILDING TO HEAT INCOMING SUPPLY AIR. USEABLE ESPECIALLY IN PLACES THAT NEED HIGH RATES OF VENTILATION SUCH AS COMMERCIAL AND INSTITUTIONAL BUILDINGS three main devices: flat plate air-to-air heat/energy exchangers, rotary heat and energy (enthalpy) wheels, and heat pipes (enthalpy)

Absorption Chiller

UTILIZE A THERMAL OR CHEMICAL PROCESS TO PRODUCE REFRIGERATION EFFECT NECESSARY TO PROVIDE CHILLED WATER NOT VCR- NO MECHANICAL COMPRESSION

Electronic Air Cleaner

effectively separate out particulate matter from air for small air volumes large air volumes require multiple units, which consumes large amounts of energy

Annual Fuel Utilization Efficiency (AFUE)

efficiency rating AFUE ACCOUNTS FOR THE EFFECT OF PART-LOAD EFFICIENCY AND CYCLIC LOSSES A SINGLE AFUE NUMBER REPRESENTS PERFORMANCE UNDER A SPECIFIC SET OF CONDITIONS serves well to compare two boilers under the same conditions residential only 78% AFUE - minimum AFUE natural gas furnaces 80-82% AFUE - medium-efficiency furnaces employing efficient heat exchangers, better intake air control, and/or blowers to exhaust combustion products >90% AFUE - high-efficiency (condensing) furnaces

Electrostatic Precipitator

ionized particle filter is a filtration device that removes fine particles, like dust and smoke, from a flowing gas using the force of an induced electrostatic charge minimally impeding the flow of gases through the unit.

Ton (Cooling)

one ton = 288,000 Btu/day = 12,000 Btu/hr = 3.516 kW based on how ice used to melt

Boiler

piece of equipment that produces hot water or steam A PIECE OF EQUIPMENT CONSISTING OF A VESSEL OR TANK-LIKE CONTAINER WHERE HEAT PRODUCED FROM THE COMBUSTION OF FUELS SUCH AS NATURAL GAS, FUEL OIL, OR COAL OR ELECTRICAL RESISTANCE HEATING IS USED TO PRODUCE HOT WATER OR STEAM TWO MAIN PARTS: FURNACE- PRODUCES HEAT BY BURNING FUEL CLOSED VESSEL- CONTAINER WHERE HOT WATER OR STEAM IS GENERATED SAFETY VALVE consists of vessel or tank-like container that hold water firebox (furnace) that produces heat by combustion of a fuel or by resistance to electrical current CLASSIFICATION (fuel type) natural gas/propane fuel oil electric solid fuel coal wood biomass automatic fuel feeding, ash extraction and soot blowing (Pressure and temperature) (steam) low pressure (<15 psig) medium pressure (15-160 psig) high pressure (> 160 psig) (Hot Water) low temperature (<250F and <160 psi) medium temperature (250 to 350F) high temperature (>350F) (Heat Exchanger Type) (Water Tube) straight tube bent tube (Fire Tube) single pass multiple pass (modular/Sectional) (Materials) (Non-Condensing) Carbon Steel Copper Cast Iron (Condensing) Stainless Steel Aluminum Cast Iron (Draft Type) Atmospheric (natural draft) Forced draft Induced draft (Burner Type) One (single) Stage High/Low Fire Modulating Boiler Capacities Residential 40-300 MBH (12-88 kW) Commercial 300MBH - 30 MMBH (88 - 8800 kW) Industrial 30 - 100 MMBH (8800 - 29300 kW) Utility 1000 MMBH and up (29300 kW and up) Electric boilers available up to 120000 kW Boiler Efficiency `THE GROSS HEAT OUTPUT, THE HEAT IN THE HOT WATER OR STEAM (IN BTU), DIVIDED BY THE ENERGY INPUT (BRU OF FUEL OR ELECTRICITY) Combustion Efficiency Includes only stack losses Thermal/Overall Efficiency Includes stack losses and jacket losses Combustion Gross/Net Efficiency gross efficiency assumes 100% condensation