Why Airtight is the Best Way to Build Homes

'Home Diagnosis' TV hosts Grace and Corbett Lunsford quickly explain why it's a mistake to avoid air sealing homes. Homes DO need to 'breathe', but not through gaps and cracks we leave in the enclosure.

[UndercoverArchitect]

Thanks for the great points about airtightness! All so helpful! "Build tight and then ventilate right" Yes!

[tweake]

People tend to forget that air flow pulls in moisture as well as takes it out. I fixed up some cracks in the floor and the window condensation dropped in half over night.
Ventlation is not always good. It needs to be the right type of ventilation.

[markn]

I think "Controllability" is the key to a home.

[preacher]

Many of us call a window...ventilation

[jl]

The only differences between a leaky house and a tight house with mechanical ventilation is one has a filter for the air and uses an expensive component that consumes electricity 24/7 and will eventually break and need replacing

A ventilator does not remove humidity. If there outside air is humid it will bring in humid air, just like a leaky house.

If the weather is nice outside and outside temps are equal to inside terms thus little air movement, you do what's been done for millennia- open a couple of windows.

Also, ach 50 is a really poor test for natural air leakage. What is the average leakage of a house with an ach50 score of 20 air changes an hour? In many climates it's as little as 0.3 actual air changes per hour.

A tracer gas test is a much more accurate test of the natural air leakage of a building

[coldfingersub]

I totally agree with airtight house but for cost to comfort balance for those customers who are not made out of money and actually have to work for a living as blue-collar workers. Living in the San Francisco Bay area you could be homeless in a T-shirt 365 days a year and only be mildly uncomfortable in the winter and barely break a sweat in the summer and have a old home that was built in 1917 that breathes a lot. And because the old homes breathe a lot when there’s a water leak in a wall or a roof it immediately dries out as soon as possible in the outer skins in these old homes are made out of real old growth redwood with nothing more than heavy felt paper has the outer skin wrapping underneath. These homes have been around for 100 years and they were easily be around for another hundred years without worrying about all the problems associated with an airtight house and a customer who cannot afford to upkeep the mechanical ventilation and will unfortunately develop water leaks that will get trapped underneath that air tight wrapping.
Myself I’m a airtight mechanical ventilator using HEPA filter air filtration into the house as a slightly positive pressure guru myself I’m all for it.