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Ductwork, furnaces and air handlers should be sealed against air leakage. The only place air should be able to leave the supply duct system and the furnace or air handling unit is at the supply… Read More

The location of the duct system can have a significant impact on the overall performance of the system—both the utility use and the ability to provide comfort. The energy loss from the ducts for… Read More

These systems are completely decoupled from the interior environment through the use of dedicated outdoor air intake and exhaust ducts connected directly to the unit. This change completely… Read More

In climates where the average monthly temperature for the coldest month of the year goes below 45°F, the temperature of the slab perimeter may be below the dew point of interior air for a significant… Read More

Crawlspaces should be designed and constructed as mini-basements.  Crawlspaces should not be vented to the exterior (see FAQ on Crawlspace Venting). They should have their floors uninsulated, the… Read More

Basements are part of a home, within the building boundary—despite repeated attempts over the years to disconnect them from the living space. Because of this, basements should be designed and… Read More

Polyisocyanurate insulation is a common commercial and residential roof and wall insulation. It has one of the highest R-values per inch of thickness among common insulations. However, labeled R-… Read More

Cavity insulation combined with insulating sheathings are common in residential wall construction. Cavity insulations can be categorized as rolled batt; blown-in or loose-fill (fibrous insulation—… Read More

 The information presented has been compiled from:ASHRAE Fundamentals - 2001Moisture Control in BuildingsCMHCNRC/IRCIEA Annex 24Manufacturer dataWhen using this information, it MUST be done in the… Read More

In building air barriers, the field of the opaque wall typically does not contribute strongly to the building’s overall air leakage.  Instead, details that connect building components are often the… Read More