Energy Code

[jtcapa1]

I just wanted to ask the users here if they have the same problems we have in the State of Washington with our Energy code.

 

Specifically, dealing with fresh make-up air?

 

New homes have to be very tight so, make-up air is designed into the house in either the windows (ports) wall (ports), intake near the furnace with a timer, or heat exchanger worked into the furnace.

 

On remodels is has always been loosely enforced.  For example the simplest solution was to call out window ports on any new windows in habitable rooms, knowing the rest of the existing house was going to be leaky, but with the very low U-value windows, many manufactures don't offer window ports.   Then there is the in-wall fresh air intakes ports, which I've never seen used.  Or the air intake near the furnace which is on a 12 hour timer.  All of which are linked to the Whole House vent fan.

 

Most of the contractors and even building inspectors tend to look the other way on remodels, so nothing gets installed.

I'm wondering what other professionals have run across with this "fresh air" issue on Remodels?

[DRAWZILLA]

I have found that with additions you have to figure the energy using the existing plus additions to get them to work

[Alaskan_Son]

Here in Alaska due to our relatively unique climate, fresh air and make-up air are huge. We use those through-the-wall "Fresh 80" and "Fresh 100" vents on a pretty regular basis. We've actually deleted the whole section allowing window vents to be part of the calculation. Those are a bit of a "poor mans" solution though. I personally prefer to use an HRV, to install a makeup air system specifically for the kitchen exhaust and then to take worst case negative pressure readings before installing any additional vents.

We try to get this stuff right regardless of whether inspectors catch it or not simply for indoor air quality, to reduce possibilities of rot and mold caused by condensation, and to meet code requirements for health reasons.

Around here, I don't think I've had a building safety inspector call it out though. It's always been voluntary on our part. The inspectors that do call it out are energy raters which to date have rally been voluntary inspections that one could choose to heed or ignore.

[Alaskan_Son]

To answer your question more specifically...

We've never been called for anything on remodels but any naturally aspirated furnace or boiler around here needs a combustion air vent anyway, so that one is a given, and we install the kitchen makeup air for any hood vents 400cfm or more "voluntarily". To date we haven't done a remodel that ended up tight enough to require anything additional ("Fresh 80s/100s ,gravity dampers, motorized dampers, etc.) so those have so far been reserved for new construction.

[DRAWZILLA]

Here in Calif. we relish make up air and actually have to install a fan that runs continuously all the time for new homes and additions over a 1000 s.f.  The reason for this is to generate a continous negative air pressure inside the home. Because windows are so tight these days, they want fresh air to rush in when you open a door or window.

[Alaskan_Son]

Be careful not to mix up ventilation requirements with make-up air requirements.  2 different things.  Makeup air is required to replace air being exhausted to the outside (i.e. for pressure balance).  Also should not be confused with relief air or intake air. 

 

I'm sure the fans you are referring to Perry, are installed to meet continuous ventilation requirements.  They are not for the purpose of makeup air...rather they might cause the NEED for makeup air.  You may already understand that, just clarifying for those that may not. 

[DRAWZILLA]

Yes, thanks Michael, although I don't think the continuous fans have enough impact on the make up air to make any difference to the make-up air, but I suppose you guys up there probably have special codes b/c its so cold.