Eight years since I asked my last question (see text below). I continue to enjoy my Rumford - the best feature of our home.
I know you are busy, but wanted to tell you of an experiment I tried which is so far working out. It's ok if you are unable to reply.
My Rumford was build with the air intake in the middle of the floor in order to meet code. Of course, it was not usable due to its location, and I understand that Rumfords draw air at the top anyway. But since I like to tinker, I kept experimenting with ways to try and use it in some way. A few weeks ago I cut out a piece of aluminum the same dimensions as the floor (36"/18"/13.5"/18") and raised it aprox. 4" with some bricks. I then built the fire on the raised platform, and opened the air intake below, so that fresh air came in, but without it blowing directly on the fire. I then monitored the air temperature in the house from 4 locations, to see if any part of the house became colder as a result of cold air being brought in through other vents (eg. fan exhausts, HRV ducts, etc.). I monitored for three hours; there was no drop in temperature anywhere, and the inglenook where the fireplace sits increased in temperature by 15 degrees (it was a fairly modest fire). There was also no smoke as a result of bringing the air in at the bottom.
This leads me to believe that the fresh air, brought in from below, comes into the room in front of the fire, and mixes in with the air that the Rumford takes in at the throat. If it continues to work I may have something permanent made, perhaps only a couple of inches above the floor.
Date: Fri, 14 Mar 2003
From: Jeff Lockhart
Subject: Re: Test
To: Jim Buckley
It's a 36 x 36 Rumford that my mason built from superior clay components. (You may not have realized that I'm the same guy that sent you measurements to get an estimate on the steel doors with a frame a few days ago.)
The fireplace is 24" deep, and the firebox is 14" deep, so there's about 10" of masonry at the back. Yes, the 415 degrees was front of the firebox, measured 2' up from the bottom. The temperature of the firebox would have varied greatly depending on whether I moved a few inches up or down. (My logs were shorter- 18 -20", so the fire was smaller than it could have been with 24-30" logs.)
I've attached a crude drawing of the fireplace- it's not to scale, but the measurements are correct. (If you decide to publish the information, let me know and I'll make a presentable drawing.) The results are yours to use if they are helpful; I'd prefer that, since I'm not an engineer, it was pointed out that it was done by an amateur homeowner.
Thanks for the correspondance- this is really interesting. When I think that I almost didn't get a Rumford, but something with closed-off doors & a blower! Our house has radiant floor heat, and I think that the combination is perfect. We keep it cooler (67-70 degrees), so that our nightly fires are pleasant. It is because of those fires that I am a little saddened at the ending of winter.
I'll await the info on the firestopping, and the estimate on the doors.
Jim, Here's the info on the laser heat-measuring device: It's made by RayTek (800-866-5478). The model I used is called the Rayngr ST. Prices vary according to how far away an accurate measurement can be taken. Jeff --- Jim Buckley
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