Fresh Air aka Mechanical Ventilation

Foobot Indoor Air Quality (IAQ) monitors are our personal favorite. They measure and record readings for temperature, humidity, dust (PM2.5) and chemical pollutants (VOCs). These are very useful for understanding if there is a problem to solve in your home, and also if it gets solved. See our complete review of 7 IAQ monitors.

Aprilaire 213 MERV 13 Air Filter Single Pack. If you have one of our Carrier/Bryant systems, this is likely your filter. Replace it every year at a minimum, maybe up to monthly if you have lots of pets. The 210 model is MERV 10, but it’s only $3 or so less, so stick with this filter. 

Broan HRV70SE. A very small heat recovery ventilator (or HRV). Don’t buy this here, they can be had for under $700 if you shop. This has two speeds, which is nice.  HRVs and ERVs don’t dehumidify incoming air, which can be a problem. I installed one of these in the 1900 Net Zero Ready case study. Humidity was a problem.


DO NOT BUY THIS. Example only. This is a large 155 pint/day whole house dehumidifier. Some have a third port which brings in outdoor air and are called ventilating dehumidifiers. You may note some in case studies. See the HVAC chapter and the upcoming fresh air chapter for more.

Duct mastic is a fast way to seal gaps in duct work. Put it on nickel thick. I put a rubber glove on, then a cotton glove on top, then smear it on. Cheap paint brushes work fine too. RCD brand is known as the gold standard. Buy an extra, go heavy. Don’t let this stuff freeze. Big boxes carry it near the duct work.

Foil tape for duct work. Best used for bath fan ducts. DO NOT use duct tape, it fails, this lasts much longer. Duct mastic is a far better solution. Available at big boxes for $8-12/roll. Look for 3M or Venture Tape, I’ve had bad luck with off brands.

IQAir GC MultiGas Air Purifier. A step up from the HealthPlus model, is supposed to filter harmful gases as well.