info
Google Groups no longer supports new Usenet posts or subscriptions. Historical content remains viewable.
Dismiss
The passive warm bedroom.
58 views
Skip to first unread message
zoe_lithoi
Dec 10, 2013, 12:37:00 AM12/10/13
to
Greetings,
How does a family of 5 (3 adults, 2 kids) keep warm in 20degF temperature in their modular home when they cannot afford electricity or propane?
Let's put all 5 of them in a 10x12', R20 bedroom. Then let's put 2 layers of $21 R7.7 4'x8' insulation foam board on the ceiling and 4 walls. The mattresses would take up about the entire floor providing approix. R15 on the floor.
The calculations after my signature indicate theoretically, that after 1 hour the room temperature is 51, after 2 hours it is 63, and after 3 hours, it is 69degF.
Home Depot has R7.7 foam board insulation for $21 (R-Tech 2 in. x 4 ft. x 8 ft)
2 layers of this would be ~R15. To cover the walls and ceiling of a 10'*12' room with 2 layers of this foam board insulation, you would need about 30 boards, i.e. $600. Ouch. BUT it's better than paying the 'typical' $300 per month for the heating bill for a 6 month winter ($1800).
-------------------
To heat this room to 70degF without adding any insulation would require a 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 $2.40 per day or $72 pre month or $432 for a 6 month winter.
Toby
The surface area of the 4 walls, floor, and ceiling would be:
A = 4*8*12 + 2*8*10 + 2*10*12 = 2^4 * [24+10+15=16*49 ~= 16*50 = 800sqft
There is 300 Btu/hr for a sedentary adult, so let's estimate, with kids, 250btu/hr and average, i.e. the amount of heat entering the room from sleeping people:
H = 5*250Btu/hr = 1250 Btu/hr
The Heat leaving the room, of Temperature, Trm, to the 20degF outside thru the 800sqft of R20 walls, floor, and ceiling is:
(Trm - 20)degF*800sqft / R20 hr-sqft-degF/Btu] = (Trm - 20)* 40 Btu/hr
The amount of heat the air in the 1000cuft (8'*10'*12' = ~1000cuft) room absorbs to go from 20degF to Trm is:
(Trm - 20)degF * 1/55 Btu/F /cuft * 1000cuft ~= (Trm - 20) * 20 Btu
I guess in the first hour this would be:
(Trm - 20) * 20 Btu/hr
The heatflow equation then, is:
1250 Btu/hr = (Trm - 20) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
1250 = (Trm - 20) * 60
Trm = 1250/60 + 20 = 41F
Since the room is now heated to 41F, the 2nd hour would be:
1250 Btu/hr = (Trm - 41) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
1250 = 60Trm - 820 -800
Trm = [2870]/60 = 48degF
Since the room is now heated to 48F, the 3rd hour would be:
1250 Btu/hr = (Trm - 48) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
1250 = 60Trm - 960 -800
Trm = [3010]/60 = 52degF
The 4th hour might be 55, the 5th hour might be 56 or 57....
Halfway thru the night, it's still cold
-----------------------------------------------------------------------------
Suppose we added R15 foam insulation to the ceiling and walls. We'll assume that the mattresses covering the floor add R15 to the floor, so that now, we have R20 + R15 = R35 everywhere
-----------------------------------------------------------------------------
(Trm - 20)degF*800sqft / R35 hr-sqft-degF/Btu] = (Trm - 20)* 23 Btu/hr
The heatflow equation then, is:
1250 Btu/hr = (Trm - 20) * 20 Btu/hr + (Trm - 20)* 23 Btu/hr
1250 = (Trm - 20) * 43
Trm = 1250/43 + 20 = 49F
Since the room is now heated to 49F, the 2nd hour would be:
1250 Btu/hr = (Trm - 49) * 20 Btu/hr + (Trm - 20)* 23 Btu/hr
1250 = 43*Trm - 980 - 460
Trm = 2690/43 = 63F
Since the room is now heated to 63F, the 3rd hour would be:
1250 Btu/hr = (Trm - 63) * 20 Btu/hr + (Trm - 20)* 23 Btu/hr
1250 = 43*Trm - 1260 - 460
Trm = 2970/43 = 69F
After the 3rd hour, the room is comfortable (69degF).
-----------------------------------------------------------------------------
Suppose we added R20 foam insulation to the ceiling and walls. We'll assume that the mattresses covering the floor add R20 to the floor, so that now, we have R40 everywhere
-----------------------------------------------------------------------------
(Trm - 20)degF*800sqft / R40 hr-sqft-degF/Btu] = (Trm - 20)* 20 Btu/hr
The heatflow equation then, is:
1250 Btu/hr = (Trm - 20) * 20 Btu/hr + (Trm - 20)* 20 Btu/hr
1250 = (Trm - 20) * 40
Trm = 1250/40 + 20 = 51F
Since the room is now heated to 51F, the 2nd hour would be:
1250 Btu/hr = (Trm - 51) * 20 Btu/hr + (Trm - 20)* 20 Btu/hr
1250 = 40*Trm - 1020 - 400
Trm = 2670/40 = 67F
Since the room is now heated to 67F, the 3rd hour would be:
1250 Btu/hr = (Trm - 67) * 20 Btu/hr + (Trm - 20)* 20 Btu/hr
1250 = 40*Trm - 1340 - 400
Trm = 2990/40 = 75F
After the 2nd hour, the room is comfortable (67degF). After the 3rd hour, the room is getting toasty (75degF).
-----------------------
2 layers of the R7.7 4'x8' 2inch thick, foam board on the 4 walls and ceiling works out to about 30 boards.
2 layers * [2*8*10 + 2*8*12 + 10*12]/(4*8)
= 2 layers * 8*[20 + 24 + 15]/(4*8)
= [20 + 24 + 15]/2)
= 29.5 boards
-------------------------------------
How big of a space heater would you need if you didn't insulate the room at all?
Let's say we wanted the room to be 70degF. and the heat from the space heater is Hsh
The heatflow equation given above becomes:
Hsh + 1250 Btu/hr = (70 - 20) * 20 Btu/hr + (70 - 20)* 40 Btu/hr
Hsh + 1250 = 50 * (40+20)
Hsh + 1250 = 50 * (60)
Hsh + 1250 = 3000
Hsh = 3000 - 1250 = 1750 Btu/hr = 1750 Btu/hr * 0.293 Watts/BTU/hr = 512Watts
How does a family of 5 (3 adults, 2 kids) keep warm in 20degF temperature in their modular home when they cannot afford electricity or propane?
Let's put all 5 of them in a 10x12', R20 bedroom. Then let's put 2 layers of $21 R7.7 4'x8' insulation foam board on the ceiling and 4 walls. The mattresses would take up about the entire floor providing approix. R15 on the floor.
The calculations after my signature indicate theoretically, that after 1 hour the room temperature is 51, after 2 hours it is 63, and after 3 hours, it is 69degF.
Home Depot has R7.7 foam board insulation for $21 (R-Tech 2 in. x 4 ft. x 8 ft)
2 layers of this would be ~R15. To cover the walls and ceiling of a 10'*12' room with 2 layers of this foam board insulation, you would need about 30 boards, i.e. $600. Ouch. BUT it's better than paying the 'typical' $300 per month for the heating bill for a 6 month winter ($1800).
-------------------
To heat this room to 70degF without adding any insulation would require a 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 $2.40 per day or $72 pre month or $432 for a 6 month winter.
Toby
The surface area of the 4 walls, floor, and ceiling would be:
A = 4*8*12 + 2*8*10 + 2*10*12 = 2^4 * [24+10+15=16*49 ~= 16*50 = 800sqft
There is 300 Btu/hr for a sedentary adult, so let's estimate, with kids, 250btu/hr and average, i.e. the amount of heat entering the room from sleeping people:
H = 5*250Btu/hr = 1250 Btu/hr
The Heat leaving the room, of Temperature, Trm, to the 20degF outside thru the 800sqft of R20 walls, floor, and ceiling is:
(Trm - 20)degF*800sqft / R20 hr-sqft-degF/Btu] = (Trm - 20)* 40 Btu/hr
The amount of heat the air in the 1000cuft (8'*10'*12' = ~1000cuft) room absorbs to go from 20degF to Trm is:
(Trm - 20)degF * 1/55 Btu/F /cuft * 1000cuft ~= (Trm - 20) * 20 Btu
I guess in the first hour this would be:
(Trm - 20) * 20 Btu/hr
The heatflow equation then, is:
1250 Btu/hr = (Trm - 20) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
1250 = (Trm - 20) * 60
Trm = 1250/60 + 20 = 41F
Since the room is now heated to 41F, the 2nd hour would be:
1250 Btu/hr = (Trm - 41) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
1250 = 60Trm - 820 -800
Trm = [2870]/60 = 48degF
Since the room is now heated to 48F, the 3rd hour would be:
1250 Btu/hr = (Trm - 48) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
1250 = 60Trm - 960 -800
Trm = [3010]/60 = 52degF
The 4th hour might be 55, the 5th hour might be 56 or 57....
Halfway thru the night, it's still cold
-----------------------------------------------------------------------------
Suppose we added R15 foam insulation to the ceiling and walls. We'll assume that the mattresses covering the floor add R15 to the floor, so that now, we have R20 + R15 = R35 everywhere
-----------------------------------------------------------------------------
(Trm - 20)degF*800sqft / R35 hr-sqft-degF/Btu] = (Trm - 20)* 23 Btu/hr
The heatflow equation then, is:
1250 Btu/hr = (Trm - 20) * 20 Btu/hr + (Trm - 20)* 23 Btu/hr
1250 = (Trm - 20) * 43
Trm = 1250/43 + 20 = 49F
Since the room is now heated to 49F, the 2nd hour would be:
1250 Btu/hr = (Trm - 49) * 20 Btu/hr + (Trm - 20)* 23 Btu/hr
1250 = 43*Trm - 980 - 460
Trm = 2690/43 = 63F
Since the room is now heated to 63F, the 3rd hour would be:
1250 Btu/hr = (Trm - 63) * 20 Btu/hr + (Trm - 20)* 23 Btu/hr
1250 = 43*Trm - 1260 - 460
Trm = 2970/43 = 69F
After the 3rd hour, the room is comfortable (69degF).
-----------------------------------------------------------------------------
Suppose we added R20 foam insulation to the ceiling and walls. We'll assume that the mattresses covering the floor add R20 to the floor, so that now, we have R40 everywhere
-----------------------------------------------------------------------------
(Trm - 20)degF*800sqft / R40 hr-sqft-degF/Btu] = (Trm - 20)* 20 Btu/hr
The heatflow equation then, is:
1250 Btu/hr = (Trm - 20) * 20 Btu/hr + (Trm - 20)* 20 Btu/hr
1250 = (Trm - 20) * 40
Trm = 1250/40 + 20 = 51F
Since the room is now heated to 51F, the 2nd hour would be:
1250 Btu/hr = (Trm - 51) * 20 Btu/hr + (Trm - 20)* 20 Btu/hr
1250 = 40*Trm - 1020 - 400
Trm = 2670/40 = 67F
Since the room is now heated to 67F, the 3rd hour would be:
1250 Btu/hr = (Trm - 67) * 20 Btu/hr + (Trm - 20)* 20 Btu/hr
1250 = 40*Trm - 1340 - 400
Trm = 2990/40 = 75F
After the 2nd hour, the room is comfortable (67degF). After the 3rd hour, the room is getting toasty (75degF).
-----------------------
2 layers of the R7.7 4'x8' 2inch thick, foam board on the 4 walls and ceiling works out to about 30 boards.
2 layers * [2*8*10 + 2*8*12 + 10*12]/(4*8)
= 2 layers * 8*[20 + 24 + 15]/(4*8)
= [20 + 24 + 15]/2)
= 29.5 boards
-------------------------------------
How big of a space heater would you need if you didn't insulate the room at all?
Let's say we wanted the room to be 70degF. and the heat from the space heater is Hsh
The heatflow equation given above becomes:
Hsh + 1250 Btu/hr = (70 - 20) * 20 Btu/hr + (70 - 20)* 40 Btu/hr
Hsh + 1250 = 50 * (40+20)
Hsh + 1250 = 50 * (60)
Hsh + 1250 = 3000
Hsh = 3000 - 1250 = 1750 Btu/hr = 1750 Btu/hr * 0.293 Watts/BTU/hr = 512Watts
Morris Dovey
Dec 10, 2013, 1:37:10 AM12/10/13
to
On 12/9/13 11:37 PM, zoe_lithoi wrote:
> How does a family of 5 (3 adults, 2 kids) keep warm in 20degF
> temperature in their modular home when they cannot afford electricity
> or propane?
Depending on how the home is sited, you might be able to try something
> How does a family of 5 (3 adults, 2 kids) keep warm in 20degF
> temperature in their modular home when they cannot afford electricity
> or propane?
like this: http://www.iedu.com/Solar/Panels/index.html
--
Morris Dovey
http://www.iedu.com/Solar/
zoe_lithoi
Jan 10, 2014, 12:56:04 PM1/10/14
to
Greetings,
It appears there are many online articles claiming they can, along a turned on computer, for example, heat a room with candles... and include making a radiant heater out of 4 'tea candles' costing 1 british pound ($1.65) for 100 of them, the candles burn for about 4 hours. Is this fact or fiction? One of the complaints was that no thermal calculations were done to support said claim, taking into account the size and insulation of the room, nor relating it's performance to how cold it is outside.
My calc's below show that the claim is reasonable for a well-insulated room (R20) heated by 5 people and 4 British Tea candles.... 58degF for the 1st hour, and 70degF for the next.
One video is at:
http://www.whydontyoutrythis.com/2013/11/how-to-easily-heat-your-home-using-flower-pots-and-tea-lights.html
The 'Characterization of Candle Flames' paper can be read at:
http://fire.nist.gov/bfrlpubs/fire05/PDF/f05141.pdf
The candle was calculated as 77±9Watt which can be converted to be 263 BTU/h
So, 4 candles would yield about 1000 Btu/hr for 4 hours. Our goals is to make it thru an 8 hour nite, so we would need 8 candles per nite which would cost 8 *$1.64/100 = 0.13 (13 cents), so over 1 month, it would cost about 50cents.
Let's add candle light heat to the calculations I made earlier in this thread about heating a a 10x12', R20 bedroom with the heat from 5 people, totaling about 1250Btu/hr with an outside temperature of 20degF.... resulting in a 41F room temperature. So the 4-candle heater 'claim' doesn't seem like it would do much good on a 20degF night.... even if combined with heat from an approix. 200 Watt (680btu/hr) computer.
Calculations are below my signature.
Toby
From before, the surface area of the 4 walls, floor, and ceiling would be:
A = 4*8*12 + 2*8*10 + 2*10*12 = 2^4 * [24+10+15=16*49 ~= 16*50 = 800sqft
There is 300 Btu/hr for a sedentary adult, so let's estimate, with kids, 250btu/hr and average, i.e. the amount of heat entering the room from sleeping people:
H (people) = 5*250Btu/hr = 1250 Btu/hr
H (4 candles) = 1000 Btu/hr
H (total) = 2250 Btu/hr
The Heat leaving the room, of Temperature, Trm, to the 20degF outside thru the 800sqft of R20 walls, floor, and ceiling is:
(Trm - 20)degF*800sqft / R20 hr-sqft-degF/Btu] = (Trm - 20)* 40 Btu/hr
The amount of heat the air in the 1000cuft (8'*10'*12' = ~1000cuft) room absorbs to go from 20degF to Trm is:
(Trm - 20)degF * 1/55 Btu/F /cuft * 1000cuft ~= (Trm - 20) * 20 Btu
I guess in the first hour this would be:
(Trm - 20) * 20 Btu/hr
The heatflow equation then, is:
2250 Btu/hr = (Trm - 20) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
Since the room is now heated to 57.5F, the 2nd hour would be:
2250 Btu/hr = (Trm - 57.5) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
2250 = 60Trm - 1150 -800
Trm = [4200]/60 = 70degF
Toby
It appears there are many online articles claiming they can, along a turned on computer, for example, heat a room with candles... and include making a radiant heater out of 4 'tea candles' costing 1 british pound ($1.65) for 100 of them, the candles burn for about 4 hours. Is this fact or fiction? One of the complaints was that no thermal calculations were done to support said claim, taking into account the size and insulation of the room, nor relating it's performance to how cold it is outside.
My calc's below show that the claim is reasonable for a well-insulated room (R20) heated by 5 people and 4 British Tea candles.... 58degF for the 1st hour, and 70degF for the next.
One video is at:
http://www.whydontyoutrythis.com/2013/11/how-to-easily-heat-your-home-using-flower-pots-and-tea-lights.html
The 'Characterization of Candle Flames' paper can be read at:
http://fire.nist.gov/bfrlpubs/fire05/PDF/f05141.pdf
The candle was calculated as 77±9Watt which can be converted to be 263 BTU/h
So, 4 candles would yield about 1000 Btu/hr for 4 hours. Our goals is to make it thru an 8 hour nite, so we would need 8 candles per nite which would cost 8 *$1.64/100 = 0.13 (13 cents), so over 1 month, it would cost about 50cents.
Let's add candle light heat to the calculations I made earlier in this thread about heating a a 10x12', R20 bedroom with the heat from 5 people, totaling about 1250Btu/hr with an outside temperature of 20degF.... resulting in a 41F room temperature. So the 4-candle heater 'claim' doesn't seem like it would do much good on a 20degF night.... even if combined with heat from an approix. 200 Watt (680btu/hr) computer.
Calculations are below my signature.
Toby
From before, the surface area of the 4 walls, floor, and ceiling would be:
A = 4*8*12 + 2*8*10 + 2*10*12 = 2^4 * [24+10+15=16*49 ~= 16*50 = 800sqft
There is 300 Btu/hr for a sedentary adult, so let's estimate, with kids, 250btu/hr and average, i.e. the amount of heat entering the room from sleeping people:
H (4 candles) = 1000 Btu/hr
H (total) = 2250 Btu/hr
The Heat leaving the room, of Temperature, Trm, to the 20degF outside thru the 800sqft of R20 walls, floor, and ceiling is:
(Trm - 20)degF*800sqft / R20 hr-sqft-degF/Btu] = (Trm - 20)* 40 Btu/hr
The amount of heat the air in the 1000cuft (8'*10'*12' = ~1000cuft) room absorbs to go from 20degF to Trm is:
(Trm - 20)degF * 1/55 Btu/F /cuft * 1000cuft ~= (Trm - 20) * 20 Btu
I guess in the first hour this would be:
(Trm - 20) * 20 Btu/hr
The heatflow equation then, is:
1250 = (Trm - 20) * 60
Trm = 2250/60 + 20 = 57.5F
Since the room is now heated to 57.5F, the 2nd hour would be:
2250 Btu/hr = (Trm - 57.5) * 20 Btu/hr + (Trm - 20)* 40 Btu/hr
2250 = 60Trm - 1150 -800
Trm = [4200]/60 = 70degF
Toby
zoe_lithoi
Jan 10, 2014, 1:29:45 PM1/10/14
to
a correction, clarification and calculation:
I had written:
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 instead 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 sleeping hours and cost about $8/month in British Tea candles.
Toby
I had written:
"Our goals is to make it thru an 8 hour nite, so we would need 8 candles per nite which would cost 8 *$1.64/100 = 0.13 (13 cents), so over 1 month, it would cost about 50cents."
Correction: 'About 50cents' should have been 'about $4.
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 instead 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 sleeping hours and cost about $8/month in British Tea candles.
Toby
Bob F
Jan 10, 2014, 8:44:20 PM1/10/14
to
zoe_lithoi wrote:
> Greetings,
>
> It appears there are many online articles claiming they can, along a
> turned on computer, for example, heat a room with candles... and
> include making a radiant heater out of 4 'tea candles' costing 1
> british pound ($1.65) for 100 of them, the candles burn for about 4
> hours. Is this fact or fiction? One of the complaints was that no
> thermal calculations were done to support said claim, taking into
> account the size and insulation of the room, nor relating it's
> performance to how cold it is outside.
You'd really want to breath the sooty htdrocarbon crud from many candles all
> Greetings,
>
> It appears there are many online articles claiming they can, along a
> turned on computer, for example, heat a room with candles... and
> include making a radiant heater out of 4 'tea candles' costing 1
> british pound ($1.65) for 100 of them, the candles burn for about 4
> hours. Is this fact or fiction? One of the complaints was that no
> thermal calculations were done to support said claim, taking into
> account the size and insulation of the room, nor relating it's
> performance to how cold it is outside.
night every night? Not me!
Not to mention the fire hazard.
songbird
Jan 11, 2014, 8:48:17 AM1/11/14
to
Bob F wrote:
...
is tight enough to keep that much heat in.
heat losses from highly insulated rooms are via
the doors/windows and without those you are asking
for suffocation.
air exchangers will be very important if you want
this to fly, and then you will need a proper design
to make sure the heat is captured and not leaking.
agreed on fire hazard too. too many people in a
small room full of mattresses and blankets, not a
good combination with candles.
i like the overall idea, but we keep the thermstat
set much lower so the heat needed to keep it warm is
much less. our whole house costs about 1500/yr to
keep warm per heating season. not bad, but it could
be better. i just don't want to sacrifice the views
out the patio doors and windows. in the middle of
the winter any light from outside is psychologically
important.
when it was just me here most of the time i would
drop the thermostat down to 50-55F for the rest of
the house and keep this room a little warmer. worked
fine for me, but it was too cold for visitors and that
wasted a lot of energy cycling the heat up and down.
songbird
...
> You'd really want to breath the sooty htdrocarbon crud from many candles all
> night every night? Not me!
>
> Not to mention the fire hazard.
i was thinking suffocation hazard in any room that
> night every night? Not me!
>
> Not to mention the fire hazard.
is tight enough to keep that much heat in.
heat losses from highly insulated rooms are via
the doors/windows and without those you are asking
for suffocation.
air exchangers will be very important if you want
this to fly, and then you will need a proper design
to make sure the heat is captured and not leaking.
agreed on fire hazard too. too many people in a
small room full of mattresses and blankets, not a
good combination with candles.
i like the overall idea, but we keep the thermstat
set much lower so the heat needed to keep it warm is
much less. our whole house costs about 1500/yr to
keep warm per heating season. not bad, but it could
be better. i just don't want to sacrifice the views
out the patio doors and windows. in the middle of
the winter any light from outside is psychologically
important.
when it was just me here most of the time i would
drop the thermostat down to 50-55F for the rest of
the house and keep this room a little warmer. worked
fine for me, but it was too cold for visitors and that
wasted a lot of energy cycling the heat up and down.
songbird
Bob F
Jan 11, 2014, 12:50:49 PM1/11/14
to
insulation is certainly way cheaper than heating.
Morris Dovey
Jan 11, 2014, 2:44:09 PM1/11/14
to
On 1/11/14 11:50 AM, Bob F wrote:
> It won't waste nearly as much as keeping the thermostat up all the time. Wearing
> insulation is certainly way cheaper than heating.
That depends on the cost of the heating.
> It won't waste nearly as much as keeping the thermostat up all the time. Wearing
> insulation is certainly way cheaper than heating.
Doing whole-structure solar heating allows (on really sunny winter days)
opening a window for comfort and fresh air. :-)
songbird
Jan 11, 2014, 5:00:55 PM1/11/14
to
Morris Dovey wrote:
...
songbird
...
> Doing whole-structure solar heating allows (on really sunny winter days)
> opening a window for comfort and fresh air. :-)
we had about 3 of those in December...
> opening a window for comfort and fresh air. :-)
songbird
Morris Dovey
Jan 11, 2014, 5:19:04 PM1/11/14
to
On 1/11/14 4:00 PM, songbird wrote:
> Morris Dovey wrote:
> ....
conventional heating systems (except that you wouldn�t have had to pay
for your heat). :-)
> Morris Dovey wrote:
> ....
>> Doing whole-structure solar heating allows (on really sunny winter days)
>> opening a window for comfort and fresh air. :-)
>
> we had about 3 of those in December...
That�s too bad - you�d have had to live all closed up like folks with
>> opening a window for comfort and fresh air. :-)
>
> we had about 3 of those in December...
conventional heating systems (except that you wouldn�t have had to pay
for your heat). :-)
songbird
Jan 12, 2014, 4:37:43 PM1/12/14
to
Morris Dovey wrote:
>songbird wrote:
...
> conventional heating systems (except that you wouldn’t have had to pay
> for your heat). :-)
without sunshine for most of December i don't see how
we would avoid paying for heat with any solar system.
the best thing i can do for an upgrade here would be to
install a solar hot water system and then on the few
sunny days in the winter i could divert some of that
for space heating. i don't think it would take much to
do that, but i've not looked into it yet.
storage of heat or electrical energy is just not that
developed yet where i could put in a system and expect it
to supply the whole heating requirement of this house
even as small as it is. i'd love to and i keep watching
developments...
songbird
>songbird wrote:
...
>> we had about 3 of those in December...
>
> That’s too bad - you’d have had to live all closed up like folks with
>
> conventional heating systems (except that you wouldn’t have had to pay
> for your heat). :-)
without sunshine for most of December i don't see how
we would avoid paying for heat with any solar system.
the best thing i can do for an upgrade here would be to
install a solar hot water system and then on the few
sunny days in the winter i could divert some of that
for space heating. i don't think it would take much to
do that, but i've not looked into it yet.
storage of heat or electrical energy is just not that
developed yet where i could put in a system and expect it
to supply the whole heating requirement of this house
even as small as it is. i'd love to and i keep watching
developments...
songbird
Morris Dovey
Jan 12, 2014, 7:14:01 PM1/12/14
to
On 1/12/14 3:37 PM, songbird wrote:
> Morris Dovey wrote:
>> songbird wrote:
> ....
> Morris Dovey wrote:
>> songbird wrote:
>>> we had about 3 of those in December...
>>
>> That�s too bad - you�d have had to live all closed up like folks with
>>
>> conventional heating systems (except that you wouldn�t have had to pay
>> for your heat). :-)
>
> without sunshine for most of December i don't see how
> we would avoid paying for heat with any solar system.
> the best thing i can do for an upgrade here would be to
> install a solar hot water system and then on the few
> sunny days in the winter i could divert some of that
> for space heating. i don't think it would take much to
> do that, but i've not looked into it yet.
>
> storage of heat or electrical energy is just not that
> developed yet where i could put in a system and expect it
> to supply the whole heating requirement of this house
> even as small as it is. i'd love to and i keep watching
> developments...
That�s a lousy situation, indeed. What we learned from the building
>
> without sunshine for most of December i don't see how
> we would avoid paying for heat with any solar system.
> the best thing i can do for an upgrade here would be to
> install a solar hot water system and then on the few
> sunny days in the winter i could divert some of that
> for space heating. i don't think it would take much to
> do that, but i've not looked into it yet.
>
> storage of heat or electrical energy is just not that
> developed yet where i could put in a system and expect it
> to supply the whole heating requirement of this house
> even as small as it is. i'd love to and i keep watching
> developments...
shown on the web page is that the panel design will collect useful
amounts of heat whenever there�s enough sunlight to read a newspaper
comfortably (clear sky not required).
Iowa isn�t generally thought of as having a lot of winter sun, but we
found that by using the concrete slab for heat storage, the building
stayed remarkably warm. It was so surprising that I picked brains here
to find out what was really going on. If you�re interested, you can read
that thread at
http://groups.google.com/group/alt.solar.thermal/browse_thread/thread/bc5706d118333556/b19cb2f048046365
The results of that discussion became part of the web page linked below.
Whole-structure (or even single-room) performance is much affected by
insulation and �tightness� of the building. Warm air rises and if
there�s a passage for it to escape through ceiling/roof, it will - but
both of these things are true regardless of heating method.
I hate for people to feel a need to retreat into a single room in order
to keep warm!
--
Morris Dovey
http://www.iedu.com/Solar/Panels
songbird
Jan 13, 2014, 1:53:17 AM1/13/14
to
Morris Dovey wrote:
...
> That’s a lousy situation, indeed. What we learned from the building
the garage with no easy method of moving
air passively from the room next to the
garage. this house was not designed or
sited for solar/passive use. i think i
would do much better to use panels on the
side of the garage to heat water and then
have a small electric pump to move the hot
water around (in a closed system i'd assume
the force needed is just that to overcome
friction).
this all is however some time away from
being done or detailed out. when i become
the owner (if i do) is when i will need to
start costing things out as if i can get
the cost right then it makes it affordable
for me to stay. if it is too expensive
then it becomes easier to sell it and move
to another place with fewer/less expensive
negatives to work around.
> Iowa isn’t generally thought of as having a lot of winter sun, but we
> there’s a passage for it to escape through ceiling/roof, it will - but
the house here is effectively two rooms and
two small rooms. it isn't set up in layers
or for getting much of the southern sun in
the winter.
if i do stick it out here one other option
is to convert the garage to another room and
then i would be right next to the south
exposure and could benefit from passive
solar heating and such without having to pump
air/water around. we'll see what happens... :)
songbird
...
> That’s a lousy situation, indeed. What we learned from the building
> shown on the web page is that the panel design will collect useful
> amounts of heat whenever there’s enough sunlight to read a newspaper
> comfortably (clear sky not required).
our south facing wall is on the side of
the garage with no easy method of moving
air passively from the room next to the
garage. this house was not designed or
sited for solar/passive use. i think i
would do much better to use panels on the
side of the garage to heat water and then
have a small electric pump to move the hot
water around (in a closed system i'd assume
the force needed is just that to overcome
friction).
this all is however some time away from
being done or detailed out. when i become
the owner (if i do) is when i will need to
start costing things out as if i can get
the cost right then it makes it affordable
for me to stay. if it is too expensive
then it becomes easier to sell it and move
to another place with fewer/less expensive
negatives to work around.
> Iowa isn’t generally thought of as having a lot of winter sun, but we
> found that by using the concrete slab for heat storage, the building
> stayed remarkably warm. It was so surprising that I picked brains here
> to find out what was really going on. If you’re interested, you can read
> stayed remarkably warm. It was so surprising that I picked brains here
> that thread at
> http://groups.google.com/group/alt.solar.thermal/browse_thread/thread/bc5706d118333556/b19cb2f048046365
>
> The results of that discussion became part of the web page linked below.
>
> Whole-structure (or even single-room) performance is much affected by
> insulation and “tightness” of the building. Warm air rises and if
> http://groups.google.com/group/alt.solar.thermal/browse_thread/thread/bc5706d118333556/b19cb2f048046365
>
> The results of that discussion became part of the web page linked below.
>
> Whole-structure (or even single-room) performance is much affected by
> there’s a passage for it to escape through ceiling/roof, it will - but
> both of these things are true regardless of heating method.
>
> I hate for people to feel a need to retreat into a single room in order
> to keep warm!
i think it makes sense to think in layers.
>
> I hate for people to feel a need to retreat into a single room in order
> to keep warm!
the house here is effectively two rooms and
two small rooms. it isn't set up in layers
or for getting much of the southern sun in
the winter.
if i do stick it out here one other option
is to convert the garage to another room and
then i would be right next to the south
exposure and could benefit from passive
solar heating and such without having to pump
air/water around. we'll see what happens... :)
songbird
Morris Dovey
Jan 13, 2014, 8:50:33 PM1/13/14
to
On 1/13/14 12:53 AM, songbird wrote:
> if i do stick it out here one other option
> is to convert the garage to another room and
> then i would be right next to the south
> exposure and could benefit from passive
> solar heating and such without having to pump
> air/water around. we'll see what happens...:)
The regulars here at alt.solar.thermal have been extremely helpful and
> if i do stick it out here one other option
> is to convert the garage to another room and
> then i would be right next to the south
> exposure and could benefit from passive
> solar heating and such without having to pump
> air/water around. we'll see what happens...:)
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!
zoe_lithoi
Nov 30, 2014, 10:52:08 AM11/30/14
to
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: $0.52/day, $15.6/month, $94 for a 6-month winter
Cost of parts: $0
***Note: Calculations below, after my signature....
2. 5 people in a room, add R20 insulation to the walls and roof:
Cost of electricity: $0
Cost of parts: $600 for foam board insulation.
3. 5 people in a room, 4 British Tea Candles, no added insulation:
Cost of electricity: $0
Cost of parts: $0.13/day, $3.90/month, $24/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 $1500 for the heating season (approix. $250/month)! ---- The whole point of the thread was that there are people living with little money for heating purposes. Just to say $1500/month is 'not bad' --- does 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 it about being inconvenienced by having 5 people sleeping in 1 room.
3rdly, I suggest solar panels, heat exchangers, water pumps are a huge expense 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 sleeping in it, with a space heater using 500Watts (0.5kw) each hour for 8 hours at 13cents per Kilwatt-hr, it would cost,
$0.52/day
in 1 month:
30days/month * 8-hours of sleep/day * 0.5kW * $0.13/kW-hr = $15.6/month
and in a 6 month winter:
6*15.6 = $94
On Monday, December 9, 2013 9:37:00 PM UTC-8, zoe_lithoi wrote:
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: $0.52/day, $15.6/month, $94 for a 6-month winter
Cost of parts: $0
***Note: Calculations below, after my signature....
2. 5 people in a room, add R20 insulation to the walls and roof:
Cost of electricity: $0
Cost of parts: $600 for foam board insulation.
3. 5 people in a room, 4 British Tea Candles, no added insulation:
Cost of electricity: $0
Cost of parts: $0.13/day, $3.90/month, $24/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 $1500 for the heating season (approix. $250/month)! ---- The whole point of the thread was that there are people living with little money for heating purposes. Just to say $1500/month is 'not bad' --- does 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 it about being inconvenienced by having 5 people sleeping in 1 room.
3rdly, I suggest solar panels, heat exchangers, water pumps are a huge expense 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 sleeping in it, with a space heater using 500Watts (0.5kw) each hour for 8 hours at 13cents per Kilwatt-hr, it would cost,
$0.52/day
in 1 month:
30days/month * 8-hours of sleep/day * 0.5kW * $0.13/kW-hr = $15.6/month
and in a 6 month winter:
6*15.6 = $94
On Monday, December 9, 2013 9:37:00 PM UTC-8, zoe_lithoi wrote:
0 new messages