If the pressure drop across a disposable air filter is more than ____% of the pressure drop across the fan, the air filter should be changed.

During a blower door test, the air infiltration into a house is lower than normal due to the depressurization of the house.

When the volume of air within a building is replaced with an equal volume of air, then a(n) _____ has occurred.

A ducted air supply opening size is the area of the opening plus the area of the mesh or bars.

The measured airflow through a blower door fan that is used to calculate air changes per hour is called _____.

If the cells in an electronic air filter are not thoroughly dried after washing, electrical arcing may occur when system is turned off.

Dirt buildup on fan motors can cause ____?  Give two examples.

A(n) ____ test shows how effectively the building envelope minimizes the amount of unconditioned air passing through into conditioned space.

What is an example of a government subsidy?

A command economy