New tight home ventilation "discussion."

Fred Harwood_2

I'm trying to come up to speed (retired in 2006) on home ventilation code. The discussion runs from must have to has set back energy conservation two decades.

Any succinct reading suggestions?

Thanks much.

Jamie Hall

I don't have any reading suggestions. I do have some experience. Two to four air changes per hour. Anything less than that and your indoor air quality gets really bad, really fast.

There are two varieties of air to air heat exchanges which I have used. One exchanges only sensible heat. The other exchanges latent heat as well (humidity). I've had very poor luck with the latter due to air quality problems.

BillW

I retired in 2008, so my recollection is about the same as yours. There are two types of units. A heat recovery unit recovers only sensible heat and an energy recovery unit that recovers both sensible and latent heat. They use fans and heat exchangers and typically run at low speed 24/7. They can be controlled by certain IAQ thermostats, humidistat/dehumidistat, timer or manual switch. They can be independently ducted, or spliced into the existing ductwork in an forced air heating/ cooling system. Heat recovery units tend to dry a space, energy recovery units tend to balance humidity. Heat recovery units need to be in a conditioned space, and have a drain for water from any ice formed and melted by their defrost cycle. Either are about 80% efficient, and may blow cold air on very cold days. A hydronic or electric re-heat will stop that. Placing the discharges high on the walls where they won't blow on people also helps. Good ductwork, thoroughly insulated is necessary. Typical capacity is about 200 cfm. Placement of the intake for the outside air is critical. It must be above the snow line, away from furnace/boiler exhausts, dryer vents, garbage cans, pet areas and car exhaust. Even so, it is still possible that you will smell your neighbors BBQ or fireplace smoke. Proper maintenance of any filters and condensate drains in vital. These ventilators are NOT kitchen exhaust fans, and while they keep air moving, may not totally eliminate all bathroom odors and steam from showers. They work on the premise of dilute and exhaust, and preheat/prewarm the incoming air. I hope this was useful.

rick in Alaska

Try this for a good read of ventilation, and heating.
http://www.cchrc.org/
Rick

wellen

Have an adequate ventilation in the attic and the crawlspace.You normally create an upward flow of air in the attic. The cool air then flows in through the vents in the eaves and out through the peak of the roof. Cross ventilation is used in the crawlspace.It is also important to have energy efficient windows.Here is a blog that shares some of the advantages of using energy efficient windows ( https://www.clerawindows.com/blog/your-411-on-energy-efficient-windows/ ). The roof and foundation ventilation also matters. There are various articles online that offer tips on how to properly ventilate the roof and foundation.

Larry Weingarten

Hello, Here is a site that just might keep you busy for hours! http://buildingscienceseminars.com/

Yours, Larry