[bloomingeek]

And let's not forget unscrupulous building owners/renters who will not employ the at least 10% fresh air intake rule on their HVAC system. This fresh air is outside air temperature, so their system has to change it's temp according to the thermostat setting, which costs money.

[account42]

Fresh air doesn't have to be outside temperatures as you can heat exchange most of the energy from exhaust to intake without putting in additional power.

[bloomingeek]

True, but the vast amount of buildings don't have this technology.