Crawl space & basement air flow patterns - problems

[meanwhile]

We have air flow problems under the house and cannot figure out how to solve it. The air flows and sometimes actually blows, from section to section and in two rooms get sucked up into the walls and then, of course, pulled into the upstairs of house. The stale crawl space air gets into the house - which I know is not good - but we are not sure how to solve the trouble. Any tips and information appreciated.

1. The main section of our house was built with a crawl space and has the furnace under one room. The Heat Man told us we have to leave at least one vent to the outside open at all times for air to get to the furnace.
2. There is a 2nd add-on section with basement but it is closed off from the crawl space area but (!) for one knocked out hole where the heat/ac duct goes through at one place.
3. Yet another add on area was added and it has holes between it and the 1st section plus vent holes that open to the 4th section.
4. The last add on area has crawl space, fairly high, and has vent holes to room #3 plus two holes that reach the basement area due to heat ducts.

Can we seal up ALL the holes from section to section so that air cannot flow? Or should we only close up the holes to the basement or to the cold rooms?

How much air is supposed to be able to move around under the house and when is it "bad" to close it off? I have read about some homes that the whole crawl space is closed off from the outside but ours is such a add-on mix and match, I don't see how it could be sealed up - not the whole thing since in the older section there is barely room to crawl and the heat ducts fill up most of it.

Any suggestions appreciated. Thank you very much.

[no1cowboy]

http://www.advancedbasementsystems.n..._space_ontario

http://www.crawlspace-basementsolutions.com/crawlspace

[cathleenc]

in wisconsin we can get energy audits and the auditor will do a great written report detailing how to solve all sorts of energy use issues, including ventilation and air sealing.

It's very common when additions are put on that the places where the two units meet are not sealed up - and thus the draft up the attic and out. We have the same problem, made worse by balloon wall framing - ie the walls are open on the inside from the attic to the floor. Every bit of heat goes straight up and out.

Once we get the audit we can then qualify for some nice rebates for doing recommended work. I'd call your utility company/companies and find out if there are any similar programs and rebates available to you.

[meanwhile]

thank you - good idea. I will have to call and see if our utility company offers the same. Thank you.