Unit 39 Residential Energy Auditing
When performing a combustion efficiency test, digital flue gas will measure what four parameters? _________, ________, ________, & ________
Carbon monoxide (CO), oxygen (O2), draft, and flu gas temperature.
What will a cracked heat exchanger cause in a combustion appliance?
A cracked heat exchanger can allow combustion chamber products to mix with the heating air that enters the living space of the house and cause serious illness.
Define excess air as it applies to a combustion appliance
Excess air as it applies to a combustion appliance is the combination of Primary, Secondary and Dilution air.
Define primary air as it applies to a combustion appliance
Primary air in a combustion chamber is defined as air that mixes with the raw gas in the burner before a flame is established.
What's the function of flame safeguard controls?
The function of the flame flame safeguard controls is to protect against unignited fuel that enters the combustion's appliance combustion chamber.
Performing a home energy audit starts with a visual inspection of a home & its energy systems which include: _________, _________, ___________, _________
- building envelope - HVAC systems - base load inspections - indoor air quality
Name four nationally recognized energy certifications for home auditors & contractors
1. Association for Energy Engineers (AEE) 2. Building Performance Institute (BPI) 3. Green Mechanical Council 4. Residential Energy Services Network (RESNET)
Name & briefly explain the five most common diagnostic tests performed during a residential energy audit
1. Blower door testing:- It gives the auditor insight on how tight or leaky the home's building envelope is overall2. Infrared scanning testing (thermal imaging camera):- in conjunction with a blower door test for best results for testing infiltration & exfiltration3. duct leakage testing:- 25% of the total energy losses can be blamed on air leakage in forced-air duct systems- leakage to the outside of the conditioned space has a much larger impact on HVAC system performance than duct leakage inside the space4. combustion efficiency & safety testing:- digital flue-gas analysis instrumentation measures CO, O2, draft, & flue-gas tempt5. HVAC/R system testing:- ?
Name seven base loads, or LAMEL loads, as they apply to a residential energy audit
1. Lights 2. refrigerators 3. freezers 4. water heaters 5. clothes dryers 6. computers 7. printers 8. copiers 9. cell phone chargers
Name & briefly explain the three broad categories of a residential energy audit
1. Screening, visual inspections and measurements: 2. Diagnostic testing 3. Numerical analysis with reporting
What is meant by a direct-vented, sealed-combustion, high-efficiency furnace?
A direct-vented, sealed-combustion, high-efficiency furnace uses air from outside for combustion using a pipe that is usually made of PVC plastic.
Briefly describe what a duct blower's function is as it applies to residential energy audits
A duct blowers function is used to measure the airtightness of forced air heating, ventilating and air-conditioning (HVAC) ductwork during residential energy audits.
Define a home energy index
A home energy index is defined as a way to compare one home to another and to characterize their efficiency through an energy index.
Define a residential energy audit:
A residential energy audit can be defined as the steps taken increase the homeowner's comfort, safety, and health and the life of the house. While conserving energy and saving the homeowner money
What can an infrared scanning camera do for an auditor that the blower door test cannot?
An infrared scanning camera can show the exact location of leaks which is something the blower door test cannot do.
Briefly define backdrafting as it applies to a combustion appliance
Backdrafting is described as the continuous spillage when the direction of chimney flow is reversed.
What's the difference between a base load & seasonal energy usage as they apply to a residential home?
Base loads include usages for all electrical needs with the exception of heating and cooling energy which are considered seasonal.
Briefly describe & write the equation for perfect (complete) combustion
Complete combustion produces carbon dioxide, water vapor and heat.
Define dilution air as it applies to a combustion appliance
Dilution air as it applies to a combustion appliance is defined as air that enters after combustion, usually at the end of the heat exchanger.
Briefly define draft as it applies to a combustion appliance
Draft as it applies to combustion appliances is pressure that moves combustion byproducts through the flue and chimney and out of the building.
What is meant by an energy conservation measure (ECM)?
Energy Conservation Measure (ECM) is the method that is applied to a residence according to their energy saving potential.
Name four causes for backdrafting, ________, _________, __________, & _________
Four causes of backdrafting include open fireplaces, cloths dryers, exhaust fans and leaky return air ducts in the combustion appliance zone.
Briefly describe & write the equation for perfect (Incomplete) combustion
Incomplete combustion occurs when a combustion reaction occurs without a sufficient supply of oxygen.
What's the difference between an induced-draft & a forced-draft combustion appliance?
Induced-draft systems have a combustion blower motor located at the outlet of the heat exchanger. Forced-draft systems push or blow combustion gases through the heat exchanger and cause a positive pressure.
One inch of water column (un. WC) is equal to how many Pascals (Pa)?
One inch of water column is equal to 250 pascals. or 250pa
One Pascal (Pa) is equal to how many inches of water column (in. WC)?
One pascal is equal to 0.00401865 inches of water column.
What's the definition between over-the-fire draft & stack (chimney) draft?
Over-the-fire draft, the draft over the fire and has a lesser eating than chimney draft. Stack draft is the draft between the combustion device and the draft diverter or flue draft.,
Define secondary air at it applies to a combustion appliance
Secondary air in a combustion chamber is defined as air that enters the combustion chamber after ignition and supports it.
Briefly define spillage as it applies to a combustion appliance
Spillage is the temporary flow of combustion byproducts from an open combustion appliance at the draft dilution port.
Briefly describe a blower door test
The blower door test is used to measure the air leakage into and out of a home. The blower door blows air out of the house bringing it to a standard pressure. The the air flowing through the blower door is measured which determines the severity of your home's air leaks and your home's energy efficiency.
Briefly describe how to check for duct leakage to the outdoors using a duct blower & a blower door
The following procedures are describe how to check for duct leakage to the outdoors using a duct blower and a blower door. • Close all windows and outside doors, all interior doors remain open. • Install blower door in a configuration to pressurize the home. • Connect duct blower to air handler or air register. • Pressurize duct system to 25 Pascals. • Pressurize the house with blower door until the pressure difference between the house and duct work is 0.0 pascals. • The Duct Blaster is set up and attached to the duct system (usually near the furnace). • The blower door is turned on and the house is pressurized to 25 Pascals. • The airflow indicated on the Duct Blaster's manometer (in cfm) quantifies duct leakage to the outdoors.
Name three common flame safeguard controls. _________, __________, & ____________
Three common flame safeguard controls are thermocouples, flame rectification and cadmium sulfide cell or photo cell.