House Temperatures

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lumbering on

Feeling the Heat
Dec 7, 2012
482
New York
Question on energy usage.

Not sure if this debate has been had before...

With a forced hot air heating system, does it take more energy to keep an unoccupied house at 65 all day, and then raise it 5 degrees with the woods stove to 70 in the evening

or keep it at 55 all day, and then raise it 15 degrees to 65 or 70 with the furnace in the evening

and then kick the stove on keep it there. (assuming stove is supplemental/ambiance heat and not full time heater)
 
I use the woodstove for 95% of my heating needs. But before that, my forced hot air was controlled by a programable thermostate, having it set 15 min before anyone got home. It takes the woodstove about a half hour during a cold start to heat things up, but stays hot long after the fire goes out.
 
Having gone through it many times in this 2,500 sq. ft. barn it takes forever to heat this joint upstairs and down 5 to 10 degrees from a cold stove. Of course downstairs it might be 90 degrees but upstairs...

The walls, furniture etc. soak up a ton of BTUs before everything else gets warm.
 
Question on energy usage.

Not sure if this debate has been had before...

With a forced hot air heating system, does it take more energy to keep an unoccupied house at 65 all day, and then raise it 5 degrees with the woods stove to 70 in the evening

or keep it at 55 all day, and then raise it 15 degrees to 65 or 70 with the furnace in the evening

and then kick the stove on keep it there. (assuming stove is supplemental/ambiance heat and not full time heater)

It would take more energy to keep your house 10 degrees warmer all day. But if you if you let it go down to 55 degrees, it will take several hours to heat it back up to 70 again.
 
It takes less energy if you let your house cool down. But it then takes a bit longer to heat up (still, it is less net energy).

Think about it this way, your heat loss from the house will be great the bigger the temperature differential (consider how hard it is to keep the house warm on a cool vay versus a really cold day).

I dont understand the people who keep their ac set the same even when they arent home. Its simply illogical, not needed, and expensive. Save a few busks and turn the temp down. (Only difference here is if this change will alter what heat source you use! Keeping the house warmer longer with the wood stove is cheaper than letting the oil furnace take over, for me).
 
Or choice three, set back 15 degrees, then have the furnace bring it up 10 before you get home, and the stove pops it up the last bit.
 
Main level, and bedroom level thermostats set at 64*F at all times for the dog when we are not home....lower level family room (rarely used) gets set at 50*F. Someone is always home to stoke the fire, so the furnace is just heating hot water for the storage tank.
 
Generally deeper/longer setbacks do save more energy, but BB makes a good point about the mass of the house taking a long time to heat back up. Before we moved to our current house, our old apartment had 50year old oil/steam heat and nothing else. I would have it setback to 60F while we were at work, and then return to 68F @5pm. By 7pm the air in the room would hit the set temp and kick off the heat (on mild days even overshoot to 70), but the couches and all the furniture and walls took a LOT longer to come up to temp so we always felt cold.... colder than if you just left it at 68 all the time.
 
Question on energy usage.

Not sure if this debate has been had before...

With a forced hot air heating system, does it take more energy to keep an unoccupied house at 65 all day, and then raise it 5 degrees with the woods stove to 70 in the evening

or keep it at 55 all day, and then raise it 15 degrees to 65 or 70 with the furnace in the evening

and then kick the stove on keep it there. (assuming stove is supplemental/ambiance heat and not full time heater)


I don't understand this at all. If you have a wood stove, then why aren't you heating it with wood during the day?
 
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I don't understand this at all. If you have a wood stove, then why aren't you heating it with wood during the day?

If I remember right it's a pretty large place they're heating.(6K) I think I remember reading the stove was more supplemental for the main level.
 
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Got it rdust. That size is a beast to heat.
 
I let it swing 10 degrees that way i can do just 1 load a day. Takes at least 24 hours from the time i light the stove till it dies 12-15 hours later and the temp slowly goes down to 70 from 80.
 
If I remember right it's a pretty large place they're heating.(6K) I think I remember reading the stove was more supplemental for the main level.

Right, big old house, bought after being abandoned for 3 years. Slowing clawing our way into an energy plan.
We are realistic, stove will be supplemental for the main living areas of 1,000 sq ft.

Had an HVAC guy in her the other day telling us it takes more energy to heat the place up 15 degrees when we get home than it does to maintain it all day when no one is here. I thought that sounded like nonsense, but wanted some trustworthy opinions from some knowledgable types, so I posted here.
 
Right, big old house, bought after being abandoned for 3 years. Slowing clawing our way into an energy plan.
We are realistic, stove will be supplemental for the main living areas of 1,000 sq ft.

Had an HVAC guy in her the other day telling us it takes more energy to heat the place up 15 degrees when we get home than it does to maintain it all day when no one is here. I thought that sounded like nonsense, but wanted some trustworthy opinions from some knowledgable types, so I posted here.

I know you may be on a budget but have you considered two wood stoves? It may seem expensive up front, but I bet it would pay off in the long run for the area you are heating. Also, natural gas prices are bound to rise over the next several years--they are unusually low right now. Something to factor into your long term plan.
 
I'd imagine anything you can knock out of that heating bill would be helpful!

$4,000 in oil last year! (and I swear we barely ran the furnace)

We installed an Energy Kinetics System 2,000 boiler and just replaced ALL the windows (originals were single pain no storms).
Stocked up on 4 cords of wood, and will have the stove cranking it out.
But new baby on the way, so we can't leave the place iceberg temps anymore.
I'm hoping for some relief this year.
 
I know you may be on a budget but have you considered two wood stoves? It may seem expensive up front, but I bet it would pay off in the long run for the area you are heating. Also, natural gas prices are bound to rise over the next several years--they are unusually low right now. Something to factor into your long term plan.

I have actually. Just need to figure out where to put it. Not this year, though.
 
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