[Greenbuilding] Back to Rumford fireplaces, tight homes & backdrafting

[Drew A. Gillett P.E.]

get rid of the kitchen fan  or convert it to the filtering recycling kind , 
or tie it into a balanced air to air htx. or put a sign on it indicating to 
open kitchen window when in use

or put an exhausto www.exhaustocom on the rumford.

or put a pressurebalancing damper on the makeup air inlet so only as much 
air as needed is let in,

or use truly sealed combustion direct vent appliances.

your advice clearly leads to eliminating as many exhaust only devices as 
possible and designing a balanced air to air htx system. which are quite 
forgiving of minor imbalances.

----- Original Message ----- 
From: "Tom St. Louis" <tom_st_louis at msn.com>
To: <greenbuilding at listserv.repp.org>
Sent: Tuesday, December 05, 2006 6:23 PM
Subject: [Greenbuilding] Back to Rumford fireplaces,tight homes & 
backdrafting


> Builder has installed Rumfords in two SIPs homes. The homes are so tight
> that when the kitchen fan is turned on, the chimney backdrafts (even with
> the combustion air supply open at the side of the fire box), this gets 
> worse
> as more fans and the clothes dryer are turned on. Even the 'supposed' 
> sealed
> combustion Rinnai on-demand water heaters backdrafted. Oh dear!
>
> More make-air sources are going to be added or maybe a larger single 
> source
> possibly behind the kitchen stove. Looking at adding sealed glass doors to
> the Rumfords to add extra insurance to prevent backdrafting.
>
> Will a wood fired Rumford firplace work having air-tight sealing
> ceramic-glass or other high temp glass doors with outside combustion air
> source? Can they be converted to gas log Rumfords with airtight sealed 
> doors
> and still work?
>
> Big reminder for everyone.........
> Add up all the maximum CFM capacities of all exhaust air fans and 
> appliances
> in your buildings while still at design stage, then plan and specify 
> make-up
> air source(s) equal to worst case for air being sucked out. Must have
> incoming make-up air equal to what is being exhausted.
>
> Add an adjustable barometric type or electronically controlled damper to
> allow needed make-up air to prevent backdrafting or sucking air through
> cracks in the building envelope. Some homes with those modern stainless
> steel 700 to 1500 cfm kitchen fans or down draft stove fans would require 
> a
> fan to bring make-up air in.
>
> Tom
>
>
>
>
> _______________________________________________
> Greenbuilding email list
> List info: 
> http://listserv.repp.org/mailman/listinfo/greenbuilding_listserv.repp.org
> List email: Greenbuilding at listserv.repp.org
> Managed by BuildingGreen, Inc. http://www.buildinggreen.com
>      publisher of Environmental Building News and GreenSpec(r)
> Hosted and archived by REPP / CREST http://www.crest.org
>