[Greenbuilding] Slab heat loss calculation

[Norbert Senf]

No, the house is being renovated, but the intent 
is just for weekend use for skiing in the winter.
I'm very much looking forward to seeing the 
performance of the heater, because in this situation
radiant panels can do things that warm air can't. 
Vertical panels are more advantageous than
horizontal (floor, ceiling), because your body's 
orientation is vertical, and the idea is to stop
mainly radiant heat loss from your body, since 
you produce about 100w on your own, at rest.

Here is a very interesting chart from the 70's of 
MRT (mean radiant temperature in a room) vs
air temperature. I'm not sure how accurate it is.
http://heatkit.com/graphics/mrt2.gif

I experienced this once on a sunny cold morning 
in the mountains in San Cristobal, Mexico. On
the sunny side of the street, you were perfectly 
comfortable, and in the shade it was quite
cold. The sun was quite strong, and the air 
temperature on both sides of the street was the same.

The MRT relates to the average temperature of all 
the surfaces that your body "sees", and the
"view factor" between your body and the various 
surfaces. Low e windows help a lot, not so much
for the lower heat loss but because your body 
"sees" the warmer room surfaces, such as the heater, in them.

Norbert

At 08:28 AM 8/25/2013 -0700, Reuben Deumling wrote:



>On Sun, Aug 25, 2013 at 5:40 AM, Norbert Senf 
><<mailto:mheat at mha-net.org>mheat at mha-net.org> wrote:
>
>Life has been good - we just did a very 
>interesting masonry heater project in Japan:
><http://www.mha-net.org/docs/v8n2/docs/japan13part1.htm>http://www.mha-net.org/docs/v8n2/docs/japan13part1.htm
>
>
>That was a most interesting tour. Thanks for sharing that link.
>
>you wrote: "It is uninsulated and almost 
>impossible to heat in the winter with kerosene 
>fired hot air heaters."  I was struck by the 
>contrast between this, and the incredible 
>attention to building the masonry heater. Are 
>there any plans to add any insulation to this house?
>
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-------------------------------------------
Norbert Senf---------- mheat(at)heatkit.com
Masonry Stove Builders
25 Brouse Rd.
RR 5, Shawville------- www.heatkit.com
Québec J0X 2Y0-------- fax:-----819.647.6082
---------------------- voice:---819.647.5092