[Greenbuilding] Passive Ventilation for Tight Houses

[Alan Abrams]

hmmm--when you take 90% of the thermo out of the siphon, is the remaining
10% enough to provide flow?

-AA

Alan Abrams AIBD
Certified Professional Building Designer NCBDC
Certified Green Professional, NAHB
Principal, Abrams Design Build LLC
alan at abramsdesignbuild.com
www.abramsdesignbuild.com
202-726-5894 o
202-291-0626 f
202-437-8583 c 
 
-----Original Message-----
From: greenbuilding-bounces at listserv.repp.org
[mailto:greenbuilding-bounces at listserv.repp.org] On Behalf Of Nick Pine
Sent: Wednesday, February 18, 2009 7:40 AM
To: greenbuilding at listserv.repp.org
Subject: Re: [Greenbuilding] Passive Ventilation for Tight Houses

Corwyn writes:

> I have been trying to work out a design for a cheap thermsiphon solar 
> heated air intake system.  Or possibly with solar PV fan assist.  I 
> would welcome thoughts.

I suggested 25 2'x8' sheets of Tyvek or Typar (about $40) for something 
like 90% heat recovery at 15 cfm. This could thermosyphon, with a 
motorized damper, but that would make the spaces between the sheets 
large, and a small (20 watt DC?) fan would raise the air velocity and 
heat transfer rate and allow ventilation at night or when indoor and 
outdoor temps are the same.

Nick