# The passive warm bedroom. - Page 3

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Posted by Morris Dovey on January 14, 2014, 1:50 am

On 1/13/14 12:53 AM, songbird wrote:

The regulars here at alt.solar.thermal have been extremely helpful and
wonderfully patient with me in my explorations, and this would be a good
place to look for help if/when you put panels on your garage.

I/we wish you warm and well!

--
Morris Dovey
http://www.iedu.com/Solar/

Posted by zoe_lithoi on January 10, 2014, 6:29 pm

a correction, clarification and calculation:

I had written:
"Our goals is to make it thru an 8 hour nite, so we would need 8 candles pe
r nite which would cost 8 *\$.64/100 = 0.13 (13 cents), so over 1 month,
it would cost about 50cents."

Correction: 'About 50cents' should have been 'about \$.
Clarification: This would include the heat of about 5 people.
Calculation: A candle produces about the same heat as a child and 'almost'
as much heat as an adult, so instead of 5 people and 4 candles, we could in
stead have 1 person and 8 candles.... i.e. these would produce enough heat
to heat the room to about 70degF in a R20 insulated 'bedroom' during sleepi
ng hours and cost about \$/month in British Tea candles.

Toby

Posted by zoe_lithoi on November 30, 2014, 3:52 pm
Hello,

I checked back on this thread after 9 or so months and was surprised to see
all the discussion. Let me summarize my 3 idea's in this thread:

1. 5 people in a room, 500Watt space heater, no added insulation, :
Cost of electricity:  \$.52/day, \$5.6/month, \$4 for a 6-month winter
Cost of parts:  \$
***Note: Calculations below, after my signature....

2. 5 people in a room, add R20 insulation to the walls and roof:
Cost of electricity:  \$
Cost of parts:  \$00 for foam board insulation.

3. 5 people in a room, 4 British Tea Candles, no added insulation:
Cost of electricity:  \$
Cost of parts:  \$.13/day, \$.90/month, \$4/winter
***NOTE: "Ventilation" should be added to this design, which would require
more candles for heating.

My comments on the other poster's comments:

1st, I savvy the comments about candles and 'lack of oxygen'. Some sort of
ventilation is needed in the case of using candles..

2ndly,  I don't savvy \$500 for the heating season (approix. \$50/month)! -
--- The whole point of the thread was that there are people living with lit
tle money for heating purposes. Just to say \$500/month is 'not bad' --- do
es not in any way solve the problem.  This isn't about anyone's desires to
have windows (which are worthless at night while sleeping anyway)  nor is i
t about being inconvenienced by having 5 people sleeping in 1 room.

3rdly, I suggest solar panels, heat exchangers, water pumps are a huge expe
nse compared to any of my 3 low-cost ideas above.

Toby

Calculations:
if one didn't add any insulation to the room, but just had 5 people sleepi
ng in it, with a space heater using 500Watts (0.5kw) each hour for 8 hours
at 13cents per Kilwatt-hr, it would cost,
\$.52/day
in 1 month:
30days/month * 8-hours of sleep/day * 0.5kW * \$.13/kW-hr = \$5.6/month
and in a 6 month winter:
6*15.6 = \$4

On Monday, December 9, 2013 9:37:00 PM UTC-8, zoe_lithoi wrote:

in their modular home when they cannot afford electricity or propane?

of  \$1 R7.7 4'x8' insulation foam board on the ceiling and 4 walls. The m
attresses would take up about the entire floor providing approix. R15 on th
e floor.

hour the room temperature is 51, after 2 hours it is 63, and after 3 hours,
it is 69degF.

8 ft)

2' room with 2 layers of this foam board insulation, you would need about 3
0 boards, i.e. \$00. Ouch. BUT it's better than paying the 'typical' \$00 p
er month for the heating bill for a 6 month winter (\$800).

500Watt space heater (plus the 5 people). I'm guessing it's about 20cents
per kilowatt, so the cost would be 10 cents per hour, or \$.40 per day or \$
72 pre month or \$32 for a 6 month winter.

= 800sqft

250btu/hr and average, i.e. the amount of heat entering the room from sleep
ing people:

u the 800sqft of R20 walls, floor, and ceiling is:

m  absorbs to go from 20degF to Trm is:

----

ume that the mattresses covering the floor add R15 to the floor, so that no
w, we have R20 + R15 = R35 everywhere

----

----

ume that the mattresses covering the floor add R20 to the floor, so that no
w, we have R40 everywhere

----

the room is getting toasty (75degF).

ling works out to about 30 boards.

at all?

ater is Hsh

= 512Watts

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 Re: The passive warm bedroom. Morris Dovey 12-10-2013
 Re: The passive warm bedroom. zoe_lithoi 01-10-2014
 Re: The passive warm bedroom. zoe_lithoi 11-30-2014
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