Hybrid Car – More Fun with Less Gas

The passive warm bedroom. - Page 3

register ::  Login Password  :: Lost Password?
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

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.


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

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.


 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,  
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

This Thread
Bookmark this thread:
  • Subject
  • Author
  • Date
please rate this thread