Core Concepts & Building Science Flashcards
(19 cards)
What are the three essential components required for combustion to occur?
The three essential things needed for combustion are fuel, oxygen, and an ignition source.
Name one common way carbon monoxide (CO) is generated.
Carbon monoxide (CO) is commonly generated by incomplete combustion, improper fuel/air mix, or flame impingement
Explain the difference between a thermal boundary and a pressure boundary in a building.
A thermal boundary is the insulation boundary that separates conditioned from non-conditioned spaces in a building
A pressure boundary is the barrier that prevents infiltration of outdoor air into the conditioned space and exfiltration of indoor air to the outside. It should be continuous and aligned with the thermal boundary to be effective in stopping most air leakage
The objective of air sealing work is to align the pressure boundary with the thermal boundary.
What is the function or purpose of a vapor barrier (vapor diffusion retarder) and where should it be appropriately located?
A vapor barrier (vapor diffusion retarder) controls the migration of water vapor into conditioned spaces, preventing condensation, mold, and rot.
The VDR should always face the warm side; towards the interior in cold climates and towards the exterior in hot, humid climates.
Common vapor control materials include kraft paper, foil, paint, and polyethylene sheeting
Briefly describe stack effect and wind effect in the context of building airflow.
Stack Effect: This refers to the natural upward movement of air within a building due to temperature differences. Warmer air rises and escapes through upper leaks, creating a negative pressure at the bottom of the house that draws in colder outside air through lower leaks. This effect can lead to contaminants like radon or soil gases being drawn into the home
Wind Effect: This describes how wind pressure on a building can create positive pressure on the windward side, forcing air into the building, and negative pressure on the leeward side, drawing air out. Both effects contribute to infiltration (outdoor air entering) and exfiltration (indoor air leaving)
What is an auditor’s immediate responsibility when identifying a building-related condition that requires health and safety remediation?
The auditor shall identify building-related conditions that may require immediate health and safety remediation.
They must communicate these situations clearly and immediately to the homeowner/occupant and recommend contacting a qualified professional for proper repair and/or maintenance.
What are the three key characteristics of radon, and what is the primary health risk associated with radon exposure?
Radon is odorless, colorless, and radioactive. It is a naturally occurring radioactive gas.
The primary health risk from radon exposure is lung cancer.
Radon can enter a home through floor or foundation cracks, plumbing penetrations, or interstitial cavities. Detection requires radon-specific testing by a qualified professional
What conditions are needed for mold growth, and what are some potential health risks?
Conditions needed for mold growth include spores, moisture, and suitable temperature.
Potential health risks from mold are asthma, allergies, and other respiratory illnesses. Mold might commonly be found in basements and bathrooms.
Fixing water leaks and moisture management problems is crucial to preventing mold.
Name two common building materials that may contain asbestos, and describe when asbestos becomes hazardous.
Two common building materials that may contain asbestos are duct wrap and siding (also floor tiles).
Asbestos becomes hazardous when it is deteriorated and crumbling or becomes airborne. The primary health risk is lung cancer.
If vermiculite insulation is present (which may contain asbestos), the homeowner should contact their state department of health.
Name two possible sources of lead in the home and one potential health risk. Who can test for lead-based products?
Two possible sources of lead in the home are paint, plumbing, and soil.
One potential health risk of lead is anemia, kidney damage, or learning disabilities.
Only a Qualified Professional can test for lead-based products in the home.
What are at least two data points collected during a combustion safety inspection and testing as specified in BPI-1200 standards?
Two data points collected are appliance CO levels, ambient CO levels, spillage/backdrafting, venting system performance, and safety controls
Name two acceptable tools to visually assess spillage as specified in BPI-1200 standards.
Two acceptable tools are a mirror, smoke pencils (or other smoke generator), or a condensing surface.
What is the minimum required slope of a vent connector as specified in BPI-1200 standards?
The minimum required slope of a vent connector is one-quarter inch per foot of positive rise from the appliance to the vertical flue
Describe the general steps to set up a home for worst-case depressurization testing in the Combustion Appliance Zone (CAZ) before appliance testing.
- Place all combustion appliances in the CAZ in standby mode [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 55].
- Ensure fires in woodstoves/fireplaces are extinguished and dampers/doors closed [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 55].
- Close all building exterior doors and windows. Close all CAZ doors. Close interior doors of all rooms except those with an exhaust fan or central forced air system return. Outdoor openings for combustion air remain open [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 55].
- Turn off any mechanical ventilation and forced air cooling or heating system blowers [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 56].
- Measure and record baseline CAZ pressure relative to outside (WRT outside) [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 56].
- Turn on exhaust equipment (clothes dryers, range hoods, other exhaust fans) at highest speed (do not operate whole house cooling fan) [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 56, 57].
- Measure and record CAZ pressure WRT outside [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 57].
- Turn on any central forced air system blowers. If this makes CAZ pressure more negative, leave on; otherwise, turn off [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 57, 58].
- Open interior doors directly leading to the CAZ. If this makes CAZ pressure more negative, leave open [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 58].
- Appliances are then turned on, starting with the smallest BTUh input, for continuous operation [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 59].
At what specific times during main burner operation should spillage and undiluted flue gas CO measurements be taken for cold vent appliances (except domestic water heaters) and domestic water heaters/warm vent appliances?
Cold Vent (except domestic water heaters)
Spillage: Assessed at 5 minutes of main burner operation [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 60].
CO measurement: Taken at 5 minutes of main burner operation [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 60].
Domestic Water Heaters / Warm Vent
Spillage: Assessed at 2 minutes of main burner operation [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 61].
CO measurement: Taken at 5 minutes of main burner operation [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 62].
What are the CO thresholds for common fossil fuel-fired combustion appliances (Central Furnace, Boiler, Water Heater, Gas Oven, Clothes Dryer)? What action is required for an unacceptable CO level?
CO Thresholds:
Central Furnace (all categories): 400 ppm air free [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 67]
Boiler: 400 ppm air free [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 67]
Water Heater: 200 ppm air free [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 67]
Oven/Broiler: 225 ppm as measured [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 67]
Clothes Dryer: 400 ppm air free [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 67]
Action for Unacceptable CO Level: Advise the homeowner/occupant that the appliance should be serviced immediately by a qualified professional [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 191]. If ambient CO levels do not exceed 70 ppm, other audit procedures may continue at the auditor’s discretion [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 191].
Describe the procedure for inspecting and testing for gas leakage on natural gas and LP gas piping systems using a Combustible Gas Detector
- Begin at the natural gas meter or LP gas tank and conduct a test for gas leakage using a CGD [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 33].
- Confirm any leak indicated by the CGD with leak detection solution [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 33].
- Hold the CGD wand within an inch of the line, starting at the first joint closest to the outlet.
- Move the CGD wand along the entire gas line at a rate of 1 inch per second with the tip above the line for natural gas and below for LP gas.
- Move the CGD wand in a 360-degree circle completely around each joint at a rate of 1 inch per second [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 34].
- The inspection includes the entire gas line and all accessible fittings from the meter/tank outlet to the appliance gas valve [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 35].
- If gas leakage is confirmed, mark the site and notify the homeowner/occupant to immediately notify the gas company and/or a qualified professional [ANSI BPI-1200-S-2017 Standard Practice for Basic Analysis of Buildings.pdf, 36].
What is the primary purpose of a blower door test in a home energy audit?
A blower door uses a calibrated fan mounted in an exterior door frame to measure how much air a home leak.
By pulling air out of the house and lowering internal pressure, outside air flows in through leaks. The fan pressure needed to maintain a test pressure indicates the house’s leakage rate
It helps measure overall house airtightness, guiding air sealing efforts and verifying improvements.
How is pressure pan testing performed in conjunction with a blower door, and what is its purpose?
With the blower door running, a manometer is turned on and its hose is attached to a port on the pressure pan.
The gasketed pan is placed over registers/grills or other penetrations (like switches/outlets) while the blower door is running to measure the pressure difference at that specific location.
Its purpose is to measure and prioritize individual duct leaks or other air leakage points, helping to identify significant leakage areas within the distribution system or building envelope.
