Over seal a house/structure?

[tjm73]

Is it possible to seal a house up too tightly?  I mean if you wrap and insulate and vapor barrior and caulk, can you make the house too sealed to allow air in/out requiring complex HVAC systems?

Reason I ask is a friend of mine's father is a conttractor and he told my friend a story about a homethey built for a guy that owned a spray foam in a can company.  He claims the owner had them seal every exterior crack and crevese with spray insulation foam.  And when the exterior door is closed quickly the air pressure in the house spikes for a moment.  He claims ifyou are inthe upstairs in a bedroom and the downstairs door is slammed shut you can feel the air pressure change.

I find this hard to believe and yet can almost see how it could be plausable.  So it leaves me confused on the topic.

[jraabe]

With house tightening comes the responsibility for ventilation.

Remember old houses that didn't have a bathroom fan? My grandmother's bathroom always smelled (and that was a leaky house built in 1952).

A modern well sealed house must have both exhaust and intake ventilation. This can be as simple as keeping windows cracked or as elaborate and high quality as a whole house ducted ventilation system with heat recovery, purification and filtration.

In our mild climate on simple houses we order the windows with slot vents (which allow a controlled amount of air in when the house is under negative pressure) combined with an upgraded, very quite bath fan that runs on a 24 hour timer so the house has air pulled through it on an owner controlled schedule. This is quite inexpensive and effective. The timer switch has a manual override.

There is a great deal on this in my book "Superinsulated Design and Construction". (order from Amazon, out of print)

Here is a link to a PDF document on ventilation strategies in use in our area. These will work in most parts of the country: (click on the blue "Chapter 8 Ventilation" link and let it load)
http://www.energy.wsu.edu/code/code_support.cfm

[tjm73]

Interesting.  I did not know that timered bathroom fans were even available.

Is their a good resource for learning about HVAC and it's importence in new high efficiency home construction?  I'll check the resource library you have gathered here too.

[jraabe]

A Tork time of day timer (such as 701A) can be setup to control any fan. Some newer controls are more sophisticated but this little unit is a standby. Get a quiet fan so it doesn't bother people going on and off. Panasonic is the best brand but the Braun QT series is OK too.

http://www.tork.com/main9n2.htm

Here's a link to Panasonic fans:
http://www.panasonic.com/consumer_electronics/bp_ventilation_fans/size_ventilation.asp