[Greenbuilding] HELP: need opinions on Rumford fireplaces

Tue Feb 6 11:03:59 CST 2007

the outdoor air  functionality depends on the resistance of airflow in the 
outdoor air duct compared to just getting it from the room.  obviously the 
room is usually easiest and dominates the source of makeup air in a typical 
fireplace. once you put doors on the fireplace (an insert?) , the outdoor 
air works. i usually use the ash dump for makeup with a duct (with damper) 
to it.

you can reduce the off heat loss of a fireplace by using a chimney top 
damper to reduce thru convection  and inserting a layer of foamglass instead 
of brick or block where the chimney passes thru the ceiling or roof 
insulation to reduce conduction.  or you can just stop the brick and 
continue thru the insulation with triple wall pipe ( and use fake brick or 
wood above the roof to get the "look" ).

if you are going to use the rumford continuously as primary heat  it should 
work fine (i'd still try to get some outdoor air near it so i don't drag the 
draft over the people.) .  if not then you need to do the above.

at least they got the chimney in the center of the house rather than on an 
outside wall like most installations.

btw, i was in an airport fbo  (lci laconia nh)  recently with a nice new 
huge rumford 6 foot by 7 foot opening.. you could stand in it. very warm and 
beautiful.  .

----- Original Message ----- 
From: "Corwyn" <corwyn at midcoast.com>
To: "Jefro" <jefro at jefro.net>
Cc: "Greenbuilder list" <greenbuilding at listserv.repp.org>
Sent: Tuesday, February 06, 2007 10:43 AM
Subject: Re: [Greenbuilding] HELP: need opinions on Rumford fireplaces

>
> On Nov 30, 2006, at 02:03, Jefro wrote:
>
>> We will have back-to-back fireplaces, one pointing into the living room
>> and one into an inglenook sort of area adjacent to the kitchen/dining
>> room.  The space set aside for the masonry is 4'0" x 5'9", with the
>> fireplaces facing on the 5'9" sides.
>
>> We had originally intended to use zero-clearance inserts, but have been
>> talked out of those by a local heating expert whom I trust.  He says
>> the
>> gas ones are reliable, but the wood-burning ones are not.  So, we're
>> going to spend the money on masonry and "real" fireplaces.  I know
>> several of you are going to reply "woodstove insert", and we considered
>> that very hard.  These are mostly decorative, though, and we really
>> want
>> fireplaces rather than woodstoves.
>
> My sister did almost exactly this.  She has a fireplace in the living
> room and another in the adjacent study.  Both rumfords, both with
> outside air.  They are moderately warm while running.  cold when not
> running.  And _really_ cold when the flue is left open (as it often
> is).  She often gets smoke down one flue when she has a fire in the
> other.  Even as 'mostly decorative' they are a huge heat sink.
>
>   She also has a wood stove in the basement, which easily heats that
> whole space.  She now wishes she had put a woodstove insert in the
> where fireplaces are.
>
>> Right now the plan is for an iron insert (with glass door) on the
>> living
>> room side,
>
> Why not just use a woodstove insert?  Or is that what you are doing and
> I misunderstand your terminology?
>
>>  and a Rumford fireplace kit on the inglenook side.  Both
>> fireboxes will have access to outside air through a vent in the
>> supporting masonry underneath.
>
> Outside air is a debated topic.  Some claim they perform no useful
> function.
>
>> We would very much like to hear from others who have experience with
>> Rumfords.  Our masonry contractor hasn't built one for several years
>> and
>> is having trouble locating local people to discuss them with.  My
>> understanding of Rumfords is that there can be problems with smoke
>> coming into the room, and we need to avoid this.  We have heard of
>> other
>> problems as well, but all seem to be related to air pressure changes
>> that can be "fixed" in a number of ways.
>
> Never found a solution to smoking problem other than opening the door
> wide.  At which point you are better off with no fire at all both from
> a heating and a decorative standpoint.
>
> You will get no 'get out of green guilt free' card here.  Even if you
> never light them, they are a heat loss.   I recommend getting 2
> woodstoves (insert or otherwise).  Ones with glass windows are as if
> not more decorative than an open fireplace.  The flames of a proper
> woodstove fire have a transparent bluish quality which is impossible to
> duplicate in an open fireplace.
>
> Thank You Kindly,
>
> Corwyn
>
> -- 
> Corwyn
> Kermit didn't know the half of it...
> http://www.greenfret.com/
> corwyn at greenfret.com
>
>
> _______________________________________________
> 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
> 