[Greenbuilding] forced air heating vent placement

[jfstraube at gmail.com]

Hi all. 
Bob's memory is correct. This has been well researched and plenty of buildings built.  
What has not been precisely defined is what combination of R-value climate and air supply strategy work 
Suffice it to say, walls with better than code insulation , good airtightness (way better than 5 ACH and usually below 3) ‎, reasonable window areas with very good to exceptional performance do work. 

Sent from my BlackBerry 10 smartphone on the Bell network.
  Original Message  
From: home-nrg
Sent: Monday, March 28, 2016 18:03
To: Green Building
Reply To: home-nrg at dnaco.net
Subject: Re: [Greenbuilding] forced air heating vent placement

Reuben,

You might check out the research done by Build America, some
years back.

As I recall,they were able to design a single family house
with all of the ducts in a central wall cavity and, by using
a more a focused grill, place the supply grill on the inside
(duct) wall and through conditioned air to the far wall. The
arrangement conditioned the room as quickly as a similarly
sized system with supplies on the outside wall.

Check their reports; don't trust my memory.

I hope this is helpful.

Bob Klahn

----- Original Message Follows -----
From: Reuben Deumling <9watts at gmail.com>
To: Greenbuilding <greenbuilding at lists.bioenergylists.org>
Subject: [Greenbuilding] forced air heating vent placement
Date: Mon, 28 Mar 2016 10:55:47 -0700

> There seems to be a tradition of placing these all the way
> out at exterior walls, and often under windows. Does this
> hark back to when windows were the coldest surfaces and
> this would--in combination with a floor vent--make for
> convective currents which could then be relied on to mix
> the warm air better?
> I'm in the process of adding four inches to the inside of
> the exterior walls on a 140 year old farmhouse and blowing
> a ton of cellulose into those deeper cavities. There will
> be exterior storm windows and the house overall should end
> up pretty tight and cozy even without the furnace turned
> on. I have to move some of these vents as they are too
> close to the existing wall; my temptation is to shorten
> the ducts, not just by a few inches but perhaps by a
> bunch. I'm curious for any thoughts or suggestions you
> might have.
> 
> Thanks very much.
> 
> Reuben
> 
> 
> _______________________________________________
> Greenbuilding mailing list
> to Send a Message to the list, use the email address
> Greenbuilding at bioenergylists.org
> 
> to UNSUBSCRIBE or Change your List Settings use the web
> page
>
http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org

_______________________________________________
Greenbuilding mailing list
to Send a Message to the list, use the email address
Greenbuilding at bioenergylists.org

to UNSUBSCRIBE or Change your List Settings use the web page
http://lists.bioenergylists.org/mailman/listinfo/greenbuilding_lists.bioenergylists.org