Blower Door and Building Diagnostics Funding

Funding for this class was provided by the Alaska Housing Finance Corporation (AHFC).

1 Wisdom and Associates, Inc.

2 Amenities

 Refreshments

 Bathrooms

 Cell Phones

 Break schedule

3 Disclaimer

The information and materials provided by the Alaska Housing Finance Corporation are not comprehensive and do not necessarily constitute an endorsement or approval, but are intended to provide a starting point for research and information. AHFC does not endorse or sell any products.

All photos and videos are property of Wisdom and Associates,

Inc. unless otherwise noted. 4 Resources • AHFC - Research Information Center

• Alaska Residential Building Manual www.ahfc.us

• Cold Climate Housing Research Center www.cchrc.org

• One stop shop for AK Energy Efficiency information www.akenergyefficiency.org About the Instructor

6 Participant Introductions • Name

• Reason for participation

• Your expectations Scope of Course • Blower door testing and techniques

• Building airflow standard

• Diagnostic pressure testing Covered In This Course • Conducting a blower door test • Interpreting results • Air tightness • Pressure imbalances in the home • Building Airflow Standard • Pressure diagnostics • Basic testing Definitions • ACH - Air Changer per Hour: the number of times per hour that the entire volume of air in a house is exchanged in one hour at a particular pressure. Generally expressed at neutral pressure and at 50 Pascals of pressure Definitions • CFM - Cubic Feet per Minute: the number of cubic feet per minute flowing through a house. • Correlation Coefficient - how well individual pressure and flow readings fit to an average curve. This number measures the accuracy of a blower door test. Definitions • ELA - Effective Leakage Area: The area, in square inches, of a hole which leaks the same amount as a house at 4 Pascals pressure difference • EqLA - Equivalent Leakage Area: The area, in square inches, of a hole which leaks the same amount as a house at a 10 Pascal pressure difference Definitions • House Volume: The volume of air inside the thermal envelope of a house. • Infiltration: Uncontrolled air leakage into a building • “n”: The slope of a leakage curve. An indicator of the size of holes in a house. A number less than .6 indicates large holes, a number greater than .7 indicates smaller holes. Definitions • Negative Pressure: Less than atmospheric pressure inside the house. Negative pressure occurs when the pressure inside the house is less than the pressure outside. Negative pressure promotes air . • Pascal - Pa: A metric unit of pressure. 50 Pascals equals 0.2 inches of water column Definitions • Positive Pressure: Greater than atmospheric pressure inside the house. Positive pressure occurs when the pressure inside outside the house is more less than pressure outside. Positive pressure promotes air exfiltration. What is a Blower Door? What is a Blower Door? • Diagnostic tool used to measure air tightness – Locate air leakage sites – Document air tightness – Estimate natural air infiltration – Document effectiveness of air sealing – Measure duct leakage What is a Blower Door? • Powerful calibrated temporarily sealed in an exterior doorway • Pulls air into or out of a building • Creates air pressure differential between inside and outside – Pressure forces air through gaps and cracks in the

What is a Blower Door Test? • Single or series of fan flow measurements from 15 to 60 Pascals – One Pa (Pascal) = .004 Inches Water Column • Test conducted at high pressure to reduce interference from wind, • “One Point” (50 Pa) test used for quick airtightness assessment Tectite What is a Blower Door Test? • Can estimate leakage between house and attached structural components – Garage, attic, crawlspace • Can estimate outside air leakage into ductwork • Assists use of chemical smoke, infrared camera Equipment Calibration • Equipment must be factory calibrated – Fans and gauges • Energy Conservatory – 2 yrs for gauges, 4 for fans • Retrotec – 5 yrs for gauges and fans • Self check between calibrations recommended Safety Considerations

• Blower door is powerful, potentially dangerous • Keep people and pets away • Plug in tightly • Do not use ungrounded or adapter plugs • Do not use if wet • Unplug if making fan adjustments • Do not reverse while blades are turning • Do not leave on for long periods (overheat) Safety Considerations • For long term operations (blower door directed air sealing) use a flow ring to increase velocity – Do not leave on low speed • Fan may automatically shut down if too hot • Turn off combustion appliances for the test! – Flame roll out, CO – Includes attaches spaces (duplex etc.) Safety Considerations • Fires and wood stove completely out – Close – Clean out ashes! • Leave the house like you found it – – Pilot lights • Put your car keys on the appliance you shut off! Manometer Gauges Two Primary Providers • Energy Conservatory • RetroTec Energy Conservatory DG-700

• 2 Independent Channels that can be read simultaneously • 4 time averaging functions • Automatically calculates flow readings for Minneapolis products Energy Conservatory DG-700

• Can measure and record pressure baselines • 50 and 25 Pascal leakage measurement at any building pressure • Can conduct an automated test with TECTITE Energy Conservatory DG-700

• Can maintain 50, 25, and 0 Pascal pressure without a computer (Cruise Mode) Retrotec DM-2

• Two independent pressure channels • Continuous time averaging • Measures and removes baseline pressures • Enter volume and area for air change and leakage ratios Retrotec DM-2

• Can directly control fan speed • 50 Pascal cruise control w/ flow, ACH and leakage measurements • 3 fan splitter available for simultaneous control of 3 fans at once Setting Up the Building Setting up the Building • Perform inspection of the home and adjacent spaces • Pollutants may be drawn into the living space by the fan – Mold – Vermiculite – Asbestos etc. Setting up the Building • Close all adjustable openings – Windows – Exterior doors – Attic access hatch – Crawlspace hatch (only if unconditioned) – Crawlspace vents – vents Setting up the Building • Open interior doors – Treat house as a single unit • Conditioned basements and crawlspaces opened Setting up the Building • Turn off combustion appliances – Turn off switch – Unplug – Set to “pilot” • If combustion appliances turn on during a depressurization test, it is possible for flames to be sucked out of the combustion air inlet (flame rollout). This is a fire hazard and can possibly result in high CO levels. Setting up the Building • Turn off combustion appliances in adjacent units of multi-family housing • Wood stoves and fire places completely out – Close damper – Clean out ashes • Turn off exhaust fans – Clothes dryer, exhaust fan, range hood Video: Setting up the house Conducting a Depressurization Test Depressurization Test • Two common test procedures – One point test – Multi point test • One point test - singe measurement at -50 Pa – Quick and simple way to measure air tightness – TECTITE not required (although useful) Depressurization Test • Multi point test – Measures over a range of pressures (60Pa to 15Pa) • Required for AHFC energy ratings • Minimum 5 to 8 different target pressures • Averages out errors, increases accuracy • Estimates leakage area of building Depressurization Test • Turn on fan for initial inspection • Increasing fan speed increases pressure differential • Frame may pop out of door if not installed properly! • At -30Pa walk through to look for doors/window popping open, ashes Can’t Reach 50 Factors • Unable to depressurize building to -50Pa, remove flow restrictions and try again • Still can’t reach -50Pa, no adjustment for DG-700 users • Manual gauges: – Take one point test at highest possible building pressure – Manually use Table 2 to estimate air flow Can’t Reach 50 Factors Can’t Reach 50 Factors • Can’t Reach 50 Factor formula: Can’t Reach 50 Factors - Errors • The actual exponent of the leaks being measured differing from the assumed exponent (N) of 0.65. • The assumed exponent value of 0.65 is based on the average observed exponent for a large sample of residential Blower Door tests Can’t Reach 50 Factors - Errors CRF 50 Example • With the fan running full speed, you are able to achieve a building pressure of 44 Pascals with a measured fan flow of 6,000 cfm. • The corresponding CRF Factor for a building pressure of 44 Pascals is 1.09. The estimated flow needed to achieve the target pressure of 50 Pascals is 6,000 x 1.09 = 6,540 cfm. CRF Exercise • With the fan running full speed, you are able to achieve a building pressure of 28 Pascals with a measured fan flow of 5,600 cfm. • What is the CRF Factor? • What is the estimated CFM50? CRF Exercise • The corresponding CRF Factor for a building pressure of 28 Pascals is 1.46. • The estimated flow needed to achieve the target pressure of 50 Pascals is 5,600 x 1.46 = 8,176 cfm. Can’t Reach 50 Factors • The TECTITE program automatically applies the CRF Factors to One-Point Test data. Can’t Reach 50 Factors • Multi-Point test • Subtract rings until target pressure is reached • Still can’t reach? Start at highest achievable pressure and work down Testing in Windy Weather • Strong, gusty winds cause fluctuations in pressure • Watch gauges and use “Time Average” function • Use multiple outdoor reference hoses • During a multi point test, errors are averaged out • If it is still too windy, automated testing may be the only option Before You Leave • Return building to original condition • Turn on combustion appliances – Turn up – Flip switch – Set temperature control on water heater – Check pilot lights Basic Test Results Basic Test Results • One point test provides a quick assessment • Multi point test provides more details - use software! Air Leakage at 50Pa • CFM50 • Airflow in cubic feet per minute needed to change building pressure to -50Pa • Equivalent to a 20 mph wind hitting the building from all directions • Determine by a one point test Air Leakage at 50Pa • Old leaky construction: CFM50 = 4,000 to 8,000 • New tight construction: CFM50 = 600 to 1,500 Air Leakage at 50Pa • Performing a one point test before and after air tightness work determines improvement • Reductions of 40% to 50% possible Example • Initial CFM50 = 3,500 • Post-work CFM50 = 2,500 • 3,500 - 2,500 X 100 = 28.6% reduction • 3,500 Exercise 1 • Initial CFM50 = 4,250 • Post-work CFM50 = 3,675 • What is the percentage of air leakage reduction? Exercise 1 • Initial CFM50 = 4,250 • Post-work CFM50 = 3,675 • What is the percentage of air leakage reduction? • 4,250 - 3,675 X 100 = 13.5% reduction • 4,250 Exercise 2 • Initial CFM50 = 5,300 • Post-work CFM50 = 2,275 • What is the percentage of air leakage reduction? Exercise 2 • Initial CFM50 = 5,300 • Post-work CFM50 = 2,275 • What is the percentage of air leakage reduction? • 5,300 - 2,275 X 100 = 57.1% reduction • 5,300 Exercise 3 • Initial CFM50 = 1,806 • Post-work CFM50 = 1,232 • What is the percentage of air leakage reduction? Exercise 3 • Initial CFM50 = 1,806 • Post-work CFM50 = 1,232 • What is the percentage of air leakage reduction? • 1,806 - 1,232 X 100 = 31.8% reduction • 1,806 Normalizing Air Leakage • Compare relative air tightness of buildings • ACH50 - at -50Pa • Compare the measured Air Leakage at 50 Pascals (e.g. CFM50) to the conditioned interior volume of the building • Used to compare different size homes ACH50 • ACH50 is calculated by multiplying CFM50 by 60 to get air flow per hour, and dividing the result by the volume of the building. • ACH50 tells how many times per hour the entire volume of air in the building is replaced when the building envelope is subjected to a 50 Pascal pressure. ACH50 Example • CFM50 = 3,000 • Building Volume = 30,000 • 3,000 X 60 = 6 ACH50 • 30,000 ACH50 Exercise 1 • CFM50 = 2,500 • Building Volume = 20,000 • What is the ACH 50? ACH50 Exercise 1 • CFM50 = 2,500 • Building Volume = 20,000 • What is the ACH 50? • 2,500 X 60 = 7.5 ACH50 • 20,000 ACH50 Exercise 2 • CFM50 = 4,000 • Building Volume = 33,275 • What is the ACH 50? • 4,000 X 60 = 7.21 ACH50 • 33,275 ACH50 Exercise 3 • CFM50 = 770 • Building Volume = 13,200 • What is the ACH 50? ACH50 Exercise 3 • CFM50 = 770 • Building Volume = 13,200 • What is the ACH 50? • 770 X 60 = 3.5 ACH50 • 13,200 ACH50 Standards • Many standards for air tightness • Program requires less than 4 ACH50 • 5 star home = usually less than 3 ACH50 • 5 star plus = usually less than 2 ACH50 Air Density Corrections • Air density changes due to temperature • Differences in temperature between inside and outside mean different flow rates, up to 10% • Correction Factors Table • Software automatically adjusts Air Density Corrections Air Density Correction Example • Multiply the measured fan flow by the appropriate correction factor from the Table • If the fan flow is 3,200 cfm, the inside temperature is 70, and the outside temperature is 40, the correction factor is 0.971 Air Density Corrections Air Density Corrections • 0.971 X 3,200 = 3,107 cfm Air Density Corrections Exercise 1 • Fan flow = 4,500 • Inside temperature = 70 • Outside temperature = 0 • What is the corrected fan flow? Air Density Corrections Exercise 1 • 0.932 X 4,500 = 4,149 cfm Exercise 2 • Fan flow = 6,250 • Inside temperature = 65 • Outside temperature = -15 • What is the corrected fan flow? Air Density Corrections Exercise 2 • 0.921 X 6,250 = 5,756 cfm Leakage Areas • Determining leakage areas accurately - use software • Estimate cumulative size of all leaks • Conduct a multi point test for accuracy • Two leakage estimates provided by TECTITE Leakage Areas • Equivalent Leakage Area (EqLA) • The area of a sharp edged orifice (a sharp round hole cut in a thin plate) that would leak the same amount of air as the building does at a pressure of 10 Pascals. Leakage Areas • Effective Leakage Area (ELA) • The area of a special nozzle shaped hole (similar to the inlet of a Blower Door fan) that would leak the same amount of air as the building does at a pressure of 4 Pascals. Leakage Areas • The calculated EqLA will typically be about 2 times as large as the ELA. • Use EqLA to demonstrate physical change in building air tightness Leakage Areas Natural Infiltration Rates • Highlights importance of mechanical ventilation • Blower doors do not measure natural infiltration • Blower Door test measures the cumulative hole size, or leakage area, in the building's • Estimates of natural infiltration rates can be made using mathematical infiltration models • TECTITE uses ASHRAE 136-1993 Natural Infiltration Rates • Natural air leakage varies with changes in weather and temperature Natural Infiltration Rates • Effective air sealing may result in the need for installation of a mechanical ventilation system Estimated Cost of Air Leakage • Blower Door Software can estimate utility costs associated with air leakage Determining Approximate Leakage Areas Approximate Leakage Areas • Several methods can be used to determine approximate leakage area • Software calculates leakage area @ 10Pa and 4Pa • Leakage area can also be approximated by taking CFM50 and dividing by 10 How Does CFM50/10 Work? • If CFM50 is 2000 • 2000/10 = 200 square inches of leakage • Quick, useful estimation tool – no computer needed • How does this compare with more sophisticated models? How Does CFM50/10 Work? • In this test result, CFM50 = 2444 • 2444/10 = 244 square inches of approximate leakage • Within 6% of TECTITE How Does CFM50/10 Work? • In this test result, CFM50 = 614 • 614/10 = 61 square inches of approximate leakage • Within 8% of TECTITE How Does CFM50/10 Work? • In this test result, CFM50 = 962 • 962/10 = 96 square inches of approximate leakage • Within 3% of TECTITE Negative Air Pressure Chart House Depressurization • The depressurization effect from exhaust devices can be predicted • Based on CFM of exhaust and CFM50 of house • Predicts depressurization in Pascals House Depressurization • Useful in retrofit applications • What will installation of additional exhaust equipment do to house depressurization? – Will negative pressure limitations be exceeded? • How will reduction in CFM50 affect house depressurization? House Depressurization

10.0 8.0 6.0 5.0 4.0 3.0

2.5 700 Pascals of House Depressurization House of Pascals 2.0 600

1.5 500

400 1.0

300 0.5

Cubic Feet Per Minute of Exhaust of Minute Per Feet Cubic 200

100

1000 2000 3000 4000 5000 House CFM50 Example 1 • House CFM50 of 3000 • 600 CFM of exhaust • What is the expected house depressurization? House Depressurization

10.0 8.0 6.0 5.0 4.0 3.0

2.5 700 Pascals of House Depressurization House of Pascals 2.0 600

1.5 500

400 1.0

300 0.5

Cubic Feet Per Minute of Exhaust of Minute Per Feet Cubic 200

100

1000 2000 3000 4000 5000 House CFM50 Example 1 • About -4.1 Pascals Example 2 • House CFM50 of 2000 • 250 CFM of exhaust • Planned CFM50 reduction of 1000 • What is the pre and post work house depressurization? House Depressurization

10.0 8.0 6.0 5.0 4.0 3.0

2.5 700 Pascals of House Depressurization House of Pascals 2.0 600

1.5 500

400 1.0

300 0.5

Cubic Feet Per Minute of Exhaust of Minute Per Feet Cubic 200

100

1000 2000 3000 4000 5000 House CFM50 Example 2 • Pre-work depressurization of -2.0 Pa • Post-work depressurization of -6.0 Pa Exercise 1 • House CFM50 is 2000 • 300 CFM of exhaust • How much can CFM50 be reduced before exceeding -5Pa of house depressurization? House Depressurization

10.0 8.0 6.0 5.0 4.0 3.0

2.5 700 Pascals of House Depressurization House of Pascals 2.0 600

1.5 500

400 1.0

300 0.5

Cubic Feet Per Minute of Exhaust of Minute Per Feet Cubic 200

100

1000 2000 3000 4000 5000 House CFM50 Exercise 1 • 1375 CFM50 produces -5Pa of house depressurization with 300 CFM of exhaust • 2000-1375 = 625 CFM50 reduction before exceeding limit • Options for reducing depressurization/increasing reduction? Exercise 2 • House CFM50 is 2000 • 200 CFM of exhaust • How much exhaust can be added before exceeding a -2Pa depressurization limit? House Depressurization

10.0 8.0 6.0 5.0 4.0 3.0

2.5 700 Pascals of House Depressurization House of Pascals 2.0 600

1.5 500

400 1.0

300 0.5

Cubic Feet Per Minute of Exhaust of Minute Per Feet Cubic 200

100

1000 2000 3000 4000 5000 House CFM50 Exercise 2 • Can add about 50 CFM of exhaust before exceeding -2Pa depressurization limit • What options are there for increasing exhaust CFM? Air Tightness Controlling Air Leakage • Why control air leakage? • Increases lifespan of building & products • Energy efficiency of building • Occupant safety Controlling Air Leakage • Uncontrolled air leakage accounts for 99% of all water vapor movement inside a home. • Vapor diffusion accounts for 1%. • Uncontrolled air leakage results in condensation inside the building walls. • Warm moist air from inside the building cools as it reaches the exterior, resulting in water and ice accumulations within the structure. Water Vapor Movement • 99% of vapor movement in cold climates is through air movement. • 4x8 sheet of gypsum board with 1 sq/in hole in it will allow 30 quarts of water through in one heating season. • Same 4x8 sheet of gypsum board without hole in it will allow only 1/3 quart of water through in one heating season. Water Vapor Movement • By controlling air movement in home you can control 99% of water vapor movement, thereby: • Protect building materials from damage • Preventing moisture issues (rot and mold) from occurring in unseen cavities. Air Leakage Basics • Two thing present for air leakage – Hole or crack – Pressure difference to push air through hole Air Leakage Causes • Air leakage within the structure is caused by pressure imbalances within the structure • Air seeks to move from areas of high pressure to areas of low pressure. Air Leakage Basics • Five Common Driving Forces in Air Leakage – Stack effect – Wind pressure – Point source exhaust devices – Duct leakage to the outside – Door closure coupled with forced air duct systems Stack Effect • Warm buoyant air rises • Warm buoyant air leaks out top of building • Cold air enters bottom of building • Positive pressure at top of building • Negative pressure at bottom of building • Depends on air temperature outside vs. inside Warm air expands, creating a positive pressure that forces air out of the home

Neutral Pressure Plane

Warm air leaving the upper portion of the house creates a negative pressure, drawing air in the lower parts of the house Neutral Pressure Plane Neutral Pressure Zone • Important to know where the neutral pressure zone within a home is. • Negative pressure below it • Negative pressure zone dangerous place to have combustion appliances (backdrafting) Wind Pressure • Wind blowing on building • Direction & intensity of wind are factors • Outside air to enter on windward side • Indoor air leaves on leeward side • Positive pressures in building on windward side • Negative pressures on leeward side Wind Direction

Positive Negative Pressure Pressure

Neutral Pressure Plane Point Source • Point source exhaust devices are fans & chimneys: kitchen, bath fans, chimneys for combustion appliances, etc. • Push air out of building when operating. • Air leaving the building from devices causes negative pressure in building. • Air drawn back into building thru holes, cracks, surrounding soils, & makeup air inlets. Outside air drawn in

Entire house under negative pressure

Indoor Air Exhausted Point Source • Point source supply devices are fans: ventilation fans, HRV • Deliver air into building when running • Air into building creates positive pressure • Pushes inside air out of the building through holes and cracks in envelope Inside Air Forced Out Outdoor Air Enters thru Entire house Supply under positive pressure Duct Leakage to Outside • Leaks in forced air duct systems (to outside): Forced air , HRV ducting in attic, underfloor • Supply leaks act like exhaust fans causing negative building pressure • Leaks in return ducts act like supply fans causing positive pressure Door Closure • Imbalances between supply and return ducts • Imbalance increased when bedroom doors closed • Cutting off bedroom supply air from hall return registers z

Supply in bedroom

Bedroom doors closed

Supply in return bedroom z z Positive Pressure Imbalances • Interior air pushed out of structure • Forces moisture into thermal envelope • Condense / Freeze • Thawing water damage • Unchecked for years – out of sight Positive Pressure Imbalances Negative Pressure Imbalances • Exterior air brought into the structure thru path of least resistance: • Combustion air contaminants • Radon • Elevated energy usage and occupant discomfort Neutral Pressure • Leaves the house subject to driving forces of wind and stack effect • If house is tight, mechanical ventilation balanced, and little/no duct leakage and adequate return air so doors can be shut – good pressure for house to maintain Common Leakage Sites • Attics / attic hatches • Baseboards & molding • Chimney • Doors & windows • Dropped ceilings • Exterior & partition walls • Lighting fixtures • Plumbing penetrations Common Leakage Sites • Electrical penetrations • Rim joists • Other cracks & holes • Wall/floor junctures • Overhangs • Cantilevered floors • Attached garages • Duct work Common Leakage Sites • Due to stack effect, most leaks are at top of building – Usually largest leakage sites & most condensation • Air sealing actives should begin at top of building • Once stack effect is mitigated, leaks at bottom of building will be less noticeable Common Leakage Sites • Important not to seal first below natural draft appliances – Can cause backdrafting • Must address leaks above natural draft appliances first and thoroughly to prevent backdrafting of natural draft appliances Methods of Controlling Air Leakage Methods • Methods for controlling air leakage • Exterior Air Barriers- material designed to block air movement. • May allow moisture vapor to pass through one-way. (Similar to Gore-Tex®) Methods • Methods for controlling air leakage • Interior Air Barrier () – material with a very low perm rating (0.6 or less) • Seeks to eliminate the transport of moisture vapor Controlling Air Leakage - Caulking • Caulking & Sealants • Not permanent - must be maintained • Used for joints that don’t move • Compatibility and durability vary Caulking & Sealant Acoustical Sealant • Bonds to most surfaces • Use where sandwiched • Staples or tape required to support seams • 5/8” joint • Very durable • Non hardening • Indoor only Acrylic Latex • Water based • Best for non-porous surfaces • Indoor only • 3/8” joint • 5 year life • Paintable Butyl Rubber • Synthetic Rubber • Bonds to most surfaces • ½” joint • 5% stretch • Paintable • 10 year life Silicone • Flexible, water tight seal • Good adhesion, may need primed on wood • 1” joint • Up to 50% stretch • 20 year life Spray Foam • Different expansion types • Bonds well except to polyethylene • Fill large joints • 20 year life Sill Gaskets • Made from polyethylene foam • Installed under bottom plates Outlet/Switch Gasket • Fit behind cover plates Backer Rod • Closed cell • Comes in a “rope” • Up to 2” diameter Neoprene Gasket • Flexible and durable • Good for plumbing pipes Gaskets • EPDM = Synthetic rubber gasket material • EPDM gaskets especially good for plumbing penetrations. • Good flexibility at high and low temperatures - allows movement without breaking seal Tapes • Vinyl Tape • Seal seams in air barriers • Foil Tape • Duct tape – do not use! Weather Stripping • Weather Stripping • Use for joints that do move • Blocks air leakage around doors and the operable parts of windows • Must close the gap and not allow air to pass. • Friction, temperature, wear and tear Weather Stripping • Apply to clean, dry surface • Felt & open cell inexpensive, inefficient • Vinyl resist moisture, more durable • Metal longest lasting and most durable Sealants for Polyethylene • Not recommended for caulking or sealing polyethylene: • Duct tape – tends to creep and leave air gaps • Silicone – creeps and does not leave smooth finish leaves uneven joints • Sandwiching polyethylene seams between two solid materials (stud and drywall or stud and strapping) Air Leakage Entry Points Attic Air Leakage • Attic air leakage greatest • Compounded by stack effect • Should be first area air sealed when retrofitting a home for air sealing • Visible signs/clues of air leakage in the attic is ice dams Attic Air Leakage • Attic by-passes contribute to ice dams and waste energy. • All penetrations into the attic need to be detailed to prevent air leakage, including: • Around plumbing stacks • Electrical wires • Wall framing • Light Fixtures Attic Air Leakage • Spray foam is an excellent sealant to use for top plate penetrations. • Caulking is unreliable as it may dry and shrink over time. • Acoustical sealant is not recommend as it may slowly run out over time. Attic Air Leakage Attic Air Leakage

The picture can't be displayed. Attic Hatch • Attic Access should have: • Gasket/weather-stripping attached to the door (caulking gets cut by homeowner) • Insulation installed on top of the door – 4” rigid mechanically fastened • Casing/trim installed over gypsum board • Secure hatch with hinge or suitcase latch Attic Hatch

Min. 4” Rigid Foam

Insulation Insulation

Access Door

Sealant Trim Attic Hatch Ice Dams • Common cause of water damage in cold climates • Three causes of ice dams • Air leakage into the attic • Not enough attic insulation • Lack of attic ventilation Ice Dams Ice Dams Ice Dams Ice Dams Ice Dams Dropped Ceilings • Determine location of thermal envelope • Keep utilities/ductwork in a warm space • Seal wall top plates to sheetrock and draftstop • Seal all joints in ductwork Dropped Ceilings

Polyethylene

Insulation

Sealant Sealant Ductwork Interior Soffits

Polyethylene Insulation

Sealant Taped Sheetrock Roof Knee Wall • Determine location of thermal envelope • Exclude knee wall and floor – Seal bottom of roof to subfloor – Seal knee wall top plates • Include knee wall and floor – Insulate knee wall and floor Roof KneeRoof Wall

Insulation Insulation Polyethylene Foam Sealant Polyethylene Sealant Roof KneeRoof Wall

Insulation Polyethylene Insulation Sealant

Insulation Polyethylene Sealant • Clearances around chimney to be determined by manufacturer’s specifications/code • Exterior combustion air with a damper should be provided to all fireboxes • Chimney should be installed within the interior of the building envelope Fireplaces • Alternatively, chimney enclosures should be installed full height to keep pipes warm and draft during ‘die down’ stage of fire • Sealed combustion, direct vent gas fireplaces eliminate need for chimneys Fireplaces

Sheetmetal

Sealant

Sealant

Polyethylene Insulation

Polyethylene

Sealant

Insulation Sealant

Sill Gasket Fireplaces

Polyethylene

Insulation Insulation

Sealant Sealant Insulation

Insulation

Polyethylene Insulation Chimney Flue

• Interior gypsum board sealed with adhesive to sheet metal flap or firestop • Alternatively you can have two halves of firestop nailed in place with sealant applied to all joints around ‘box’ Chimney Flue

High Temp Sealant High Temp Sealant Insulation Shield

Insulation Insulation

Sheetmetal Firestop Chimney Flue

Sealant

Sealant Chimney Flue

Two Halves Hi Temp Sealant of Firestop

Sealant Exterior Walls

• Polyethylene of 6 mil or greater should be used • Few seams as possible • Seams overlapped by minimum of 1 framing cavity • Seal with acoustical sealant • Use staples at seams and edges • Avoid installing too tightly Exterior Walls

Overlapped minimum 1 stud cavity

Acoustical Sealant Partition Walls

• Partition walls should have strip of polyethylene installed behind it • Result is a joint that can be sealed with one layer of caulk and polyethylene under drywall. Exterior Walls

Vapor barrier tab placed behind interior partition at framing stage

Acoustical Sealant w/ vapor barrier overlap Vapor Barrier Tab Partition Walls

• Hold interior partition walls 3/4” in from the exterior wall • Polyethylene then installed continuously over the exterior wall and drywall is passed through the space between the partition and exterior wall. • Can be difficult to make wall air tight when electrical and plumbing are in place before drywall is installed. Exterior Walls

¾” gap

¾” gap Electrical Penetrations

• Sealant required at exterior penetration site • Sealant required at interior penetration site Electrical Panels

Sealant Sealant Electrical Boxes

• Airtight outlet boxes installed in exterior walls and insulated ceilings. • “Wide lip” boxes to seal with caulk directly to box • Foam/caulk never placed inside electrical box Electrical Boxes Vapor Barrier Box Electrical Boxes

Sealant Vapor Barrier Box Vapor Barrier Box Electrical Wires

• Locate wires along plates or against studs to minimize insulation compression when batts are used • All electrical penetrations to attic, though top and bottom plates should be sealed with expanding foam • Air can also leak through service penetrations in studs where interior walls intersect exterior walls Electrical Wires Electrical Wires Electrical Wires Foam Gaskets

• Install foam gaskets inside existing switch/outlet covers Light Fixtures

• Tape boxes to interior air barrier • Caulk wiring penetrations Light Fixtures Light Fixtures Light Fixtures Recessed Lighting

• Recessed lighting can be responsible for air leakage and heat loss into attic spaces. • Recessed lights rated or not rated for insulation contact (IC) • Should be sealed regardless of rating Recessed Lighting Recessed Lighting Recessed Lighting Recessed Lighting Recessed Lighting

Attic Space

Plywood , OSB or foam board enclosure, sealed at all sides

Sealant

Sealant

Recessed Light

Insulation

Sealant Recessed Lighting

Roof Deck

Air space between insulation and roof decking

Sealant Insulation IC Rated Recessed Light

Sheetrock

Sealant Recessed Lighting

• Recessed lights not rated for IC or not air tight should not be installed in a cathedral ceiling • Ice dams and condensation issues. • Track lighting a better choice. Plumbing Penetrations

• Sealant used for plumbing penetrations should be flexible and non-hardening as plumbing pipes will expand and contract • Caulk/seal/foam around all pipe penetrating into attic spaces or other insulated ceilings, vented crawlspaces, and garages. Plumbing Penetrations

Rubber Gasket, hole slightly smaller than Sealant pipe Plumbing Penetrations Plumbing Penetrations Plumbing Rim Joist Penetrations

• Sealant should be installed at the rim closure from the inside • Sealing at the exterior siding is not as effective Rim Joist Penetrations

Sealant Tub/Show Stalls

• Tub, shower stalls, and one piece tub shower enclosures on exterior walls can be huge air leakage points. • Prior to installation the entire height of interior surface of the exterior wall should be insulated and polyethylened prior to tub- shower installation. Tub/Show Stalls Sealant Sealant

Insulation Insulation Foam Polyethylene Polyethylene Tub/Show Stalls

Sealant

Polyethylene

Sealant Doors

• Sliding patio doors are large sources of heat loss because of large pieces of glass and lack of good air seal on sliding mechanism. • French doors have more positive seal against air leaks. • Single French door with adjacent fixed window even less air leakage. Doors

• The space between door frame and rough opening should be insulated with polyurethane foam. • Do not overfill – can warp frame • Do use low expanding type foam. • Air barrier should be continuous and sealed directly to the door frame. Insulated Header Doors French Door Air Leakage Weather-stripping Doors

• Choose the appropriate door sweeps and thresholds for the bottom of the doors. • Weatherstrip the entire door jamb. • Apply one continuous strip along each side. • Make sure the weatherstripping meets tightly at the corners. • Use a thickness that causes the weatherstripping to tightly press between the door and the door jamb when the door closes. Windows

• The space between window frame and rough opening should be insulated with polyurethane foam. • Do not overfill – can warp frame • Do use low expanding type foam. • Air barrier should be continuous and sealed directly to the window frame. Windows Windows Windows Windows Baseboard & Molding

• Can be sealed in a retrofit situation • Identify leaky areas and seal w/ foam or caulking • Blower door and thermal cam/smoke puffer Baseboard & Molding Baseboard & Molding Baseboard & Molding Garages

• Floor over a garage (tuck under garage) • Floor cavity insulation should be installed Electrical wires passing to exterior should be sealed with foam sealant or caulking • Blocking or solid joist positioned over wall /floor intersection to act as draft stop Garages

Interior Sealed Subfloor

Sealant

Sealant Interior Garage

Polyethylene Garage Overhead Doors

• Overhead doors can be very leaky • Brushes better than gaskets • Mechanical adjustment of the tracks. Garage Overhead Doors Garage Overhead Doors Rim Joist Air Leakage

• Use gaskets or sealants and adhesives • Should use continuous bead of subfloor adhesive along entire edge(s) • Penetrations in rim joist should be sealed with expanding foam on inside and again on outside with sealant Rim Joist Air Leakage

Sealant

Sealant Rim Joist Air Leakage

Sealant

Sealant

Sealant

Conduit sealed w/ putty Sill Gasket Rim Joist Air Leakage

• Proper sealing and insulating or rim joist critical! • Following pictures show a poor seal Rim Joist Air Leakage Rim Joist Air Leakage Rim Joist Air Leakage

• Foam a better choice for rim joist Rim Joist - Spray Foam Rim Joist - Spray Foam Rim Joist - Batt/None Cantilevered Floors

• Floor cavity insulated • Wood or rigid insulation blocking which is sealed around edges at ‘end’ of cantilevered section Cantilevers

• Solid block between subfloor and top of wall, seal all edges. • Use subfloor as part of interior air barrier • Caulk/seal subfloor edges • Seal subfloor to bottom plate Offset Floor

Polyethylene

Sealant Sealant Insulation

Insulation Solid Blocking, sealed all edges

Sealant Polyethylene Insulation Offset Ceiling

Polyethylene

Sealant Insulation

Insulation Sealant Sealant

Polyethylene Insulation Finding Other Cracks & Holes

• Other cracks & holes are common • Usually find them where envelope is weak • Use of smoke or hand while running blower door will exacerbate leakage • Look for signs of moisture • Look for signs of sooting • Other visual clues Building Airflow Standard Building Airflow • When changes are made to a building shell requiring the use of a blower door, building airflow standard must be calculated • Building Airflow Standard is how much ventilation is needed for the occupants of the home • Building Airflow Standard based on ASHRAE 62-2010 w/ amendments Building Airflow • Adequate building airflow (CFM 50) required for occupant health and safety • Calculations based on: • Number of occupants (if unknown: number of bedrooms +1) • Climate zone Building Airflow • A target CFM50 is used to determine the adequacy of the natural ventilation rate • In other words, does the CFM50 = enough natural ventilation, or does mechanical ventilation have to be recommended? Building Airflow • Building Airflow Standard (CFM50) required is: • (62-2010 ventilation requirement * “N”) = CFM50 What Counts as Square Footage? • Only habitable space counts for square footage in the building airflow standard • Heated, livable space • Does not include garages, attics, crawlspaces Ventilation Rate • Based on square footage and number of occupants • Follow ventilation Equation A4.1a Ventilation Rate • Based on square footage and number of occupants • Follow ventilation Equation A4.1a

• Qfan = 0.01Afloor + 10(Nbr +1)

• Qfan = fan flow rate in cubic feet per minute

• Afloor = floor area in square feet

• Nbr = number of bedrooms Ventilation Example 1

• 1500 square foot home with 3 bedrooms, how much ventilation?

• Qfan = 0.01Afloor + 10(Nbr +1)

• Qfan = 0.01*(1500) + 10(3+1)

• Qfan = 15 + 40

• Qfan = 55 Ventilation Example 2

• 3200 square foot home with 5 bedrooms, how much ventilation?

• Qfan = 0.01Afloor + 10(Nbr +1)

• Qfan = 0.01*(3200) + 10(5+1)

• Qfan = 32 + 60 • Qfan = 92 Ventilation Exercise 1

• According to equation A4.1a, how much ventilation is required for a 1700 square foot home with 2 bedrooms? Ventilation Exercise 1

• 47 CFM • 1700 * .01 = 17 • 2 bedrooms plus 1 = 3 • 3*10 cfm = 30 • 17 + 30 = 47 cfm Ventilation Exercise 2

• According to equation A4.1a, how much ventilation is required for a 4350 square foot home with 4 bedrooms? Ventilation Exercise 2

• 93.5 CFM • 4350 sq ft 8 .01 = 43.5 cfm • 4 bedrooms = 1 = 5 , • 5 * 10 = 50 cfm • 43.5 + 50 = 93.5 cfm Ventilation Exercise 3

• According to equation A4.1a, how much ventilation is required for a 2600 square foot home with 3 bedrooms? Ventilation Exercise 3

• 66 CFM • 2600 * .01 = 26 • 3 bedroom +1 = 4 • 4*10=40 • 26 + 40 = 66 cfm N Factor/Climate Factor

• Climate factor, adjusted for the height of the building • Climate factor varies by community, ranges from 6 to 24 in Alaska • Climate factor adjusted for building height • Also adjusted for wind shielding in Alaska N Factor/Climate Factor What is Wind Shielding?

• Shielded - Urban areas with high buildings or sheltered areas. Buildings surrounded by trees, bermed earth, or higher terrain. • Average - Buildings in a residential neighborhood or subdivision setting, with yard space between buildings. 80-90% of houses fall in this category. • Unshielded - Buildings in an open setting with few buildings or trees around. Buildings on top of a high hill or ocean front, exposed to winds. Wind Shielding Example 1

• What is the climate factor for a 2 story home with average wind shelter in Anchorage? Wind Shielding Example 2

• What is the climate factor for a 1 story home with shielded wind shelter in Anchorage? Wind Shielding Exercise 1

• What is the climate factor for a 2.5 story home with Unshielded wind shelter in Fairbanks? Wind Shielding Exercise 1

• What is the climate factor for a 2.5 story home with Unshielded wind shelter in Fairbanks? Wind Shielding Exercise 2

• What is the climate factor for a 4 story home with average wind shelter in Ketchikan? Wind Shielding Exercise 2

• What is the climate factor for a 4 story home with average wind shelter in Ketchikan? Climate Factor Discussion • Climate factors are larger for buildings that are shorter and for buildings that are sheltered • Shorter, sheltered building get less natural ventilation from wind and stack effect • Essentially, shorter, sheltered buildings need to be leakier to have “satisfactory” natural ventilation BAS Example 1 • 1 story house, Fairbanks, shielded wind shielding, volume of 1500 square feet of habitable space and 3 bedrooms. What is the Building Airflow Standard? BAS Example 1 • Climate factor is 21.6 BAS Example 1 • 1500 square feet, 3 bedrooms

• Qfan = 0.01*(1500) + 10(3+1)

• Qfan = 15 + 40 • 55 cfm ventilation rate

• 55 cfm * 21.6 climate factor = 1188 CFM50 BAS Example 2 • 2 story house located in Anchorage, average shielding, a volume of 3250 square feet of habitable space and 6 bedrooms. What is the Building Airflow Standard? BAS Example 2 • Climate factor is 15.2 BAS Example 2 • 3250 square feet, 6 bedrooms

• Qfan = 0.01*(3250) + 10(6+1)

• Qfan = 32.5 + 70 • 102.5 cfm ventilation rate

• 102.5 cfm * 15.2 climate factor = 1558 CFM50 BAS Exercise 1 • What is the building airflow standard for a 1 story house in Ketchikan, unshielded, with 1225 habitable square feet and 3 bedrooms? BAS Exercise 1 • Climate factor is 15.4 BAS Exercise 1

• 1225 square feet, 3 bedrooms

• Qfan = 0.01*(1225) + 10(3+1)

• Qfan = 12.25 + 40 • 52.25 cfm ventilation rate

• 52.25 cfm * 15.4 climate factor = 804.65 CFM50 BAS Exercise 2 • 1.5 story home in Homer with average wind shielding, 1350 habitable square feet, and 4 bedrooms. What is the Building Airflow Standard? BAS Exercise 2 • Climate zone is 16.7 BAS Exercise 2 • 1350 square feet, 4 bedrooms

• Qfan = 0.01*(1350) + 10(4+1)

• Qfan = 13.5 + 50 • 65.5 cfm ventilation rate

• 65.5 cfm * 16.7 climate factor = 1093.85 CFM50 Where is all this going? • Calculating the Building Airflow Standard is important for energy rated homes • If the CFM50 does not meet the BAS, then mechanical ventilation must be recommended Where is all this going? • If the CFM50 of a house is greater than the BAS, then no additional ventilation is recommended • If the CFM50 is less than the BAS, mechanical ventilation is recommended • If mechanical ventilation is present, must meet minimum flow rates or the difference made up BAS Examples • CFM50 = 1500 • BAS = 1000 • CFM50 greater, no change required

• CFM50 = 800 • BAS = 900 • CFM50 is less ventilation must be recommended. How Much Ventilation?

• Minimum recommended amount established when calculating the BAS • All other system requirements for mechanical ventilation covered in separate class BAS Exercise 1

• Take the following information and determine the BAS and ventilation needs for the building

50’

Kotzebue 1 story, unshielded 24’ 585 Habitable CFM 50 4 bedrooms BAS Exercise 1

• Answers: • BAS = 744 CFM • Minimum Recommended Mechanical Ventilation : 62 CFM • How did we get that? BAS Exercise 1

• Habitable square footage: 50*24 = 1200 square feet • Climate Factor = 12 BAS Exercise 1

• Whole House Ventilation Rate: • 1200*.01 + 10*5 = 62 CFM • 62*12 = 744 BAS • Blower door cfm50 is less than BAS, ventilation recommended BAS Exercise 1

MARS BAS Spreadsheet Reference Actual Community Wind Shielding Stories Climate Factor Community Kotzebue Kotzebue Unshielded 1 12

Blower Door CFM Whole House Square Footage Number of Building Airflow 50 (Habitable Ventilation Rate Habitable Space Bedrooms Standard (cfm) Space) (cfm) 1200 4 585 62 744

Mechanical Ventilation Recommended!

Minimum Measured Mechanical Mechanical Ventilation Ventilation (cfm) (if Recommended applicable) (cfm) 0 62 BAS Exercise 2

• Take the following information and determine the BAS and ventilation needs for the building

30’ 20’

City of Juneau Shielded 1150 CFM50 3 bedrooms 26’ 25 CFM mechanical ventilation

st 1 floor living space 1st floor tuck under garage nd 2 floor living space 2nd floor living space BAS Exercise 2

• Answers: • BAS = 1100 CFM • Minimum Recommended Mechanical Ventilation : N/A • How did we get that? BAS Exercise 2

• Habitable square footage: (26*30)+(26*50) = 2080 square feet • Climate Factor = 18.1 BAS Exercise 2

• Whole House Ventilation Rate: • 2080*.01 + 10*3 = 60.8 CFM • 60.8*18.1 = 1100.5 BAS • Blower door cfm50 is greater than the BAS, ventilation is not recommended BAS Exercise 2

MARS BAS Spreadsheet Reference Actual Community Wind Shielding Stories Climate Factor Community Juneau Juneau City Shielded 2 18.1

Blower Door CFM Whole House Square Footage Number of Building Airflow 50 (Habitable Ventilation Rate Habitable Space Bedrooms Standard (cfm) Space) (cfm) 2080 3 1150 60.8 1100.48

Mechanical Ventilation Not Recommended

Minimum Measured Mechanical Mechanical Ventilation Ventilation (cfm) (if Recommended applicable) (cfm) 25 N/A