How many BTU's do I need?

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jslinger

Member
Jan 1, 2013
181
Vermont
I was hoping someone with some knowledge about pellet stoves, or heating in general would be able to help me.
I live in Vermont, in a 2800 sq ft, pretty open, 10 year old home. I am looking for a stove that will heat my house sufficiently when it is down to 0 degrees outside. Any lower, and I will just turn on the boiler.
We currently heat with an oil boiler. We are a rather cheap couple, and only run the heat on the main floor. The house is well insulated, so the upstairs is typically around 2 degrees colder than the main floor. We keep the thermostat at 65 when we are home, and 55 when we are gone, and while we are sleeping. We don't turn the heat on in the basement, and it stays around 60 all of the time. I am essentially heating an 1100 sq ft main floor.
I was hoping someone could make a recommendation of BTU's needed in my situation. It is greatly appreciated. Thank you.
 
Why not size the stove appropriately and forget heating with the boiler? Cheaper.

I'm mildly Harman biased so the P61 comes to mind. Unless you have tall cathedral/vaulted ceilings, a P38/43 could very likely handle it, especially since you prefer a bit cooler temps.
 
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I am Harman biased as well. I was considering going with the xxv. I was under the impression that running it harder is more efficient. I wasn't sure if the xxv would be too big to run at a higher level, without overheating our living space.
 
I too am Harman biased and my opinion is that an 1100 square foot open floor only 10 years old can be heated by any of the Harman stoves. In that new of a house im sure its well insulated, tight and has good windows and doors. You will get a ton of opinions on here because there are lots of stoves that can accomidate you. I have a p61 in a newer home and it heats 1800 square feet on 2 floors into the upper 70s for about a bag a day.
 
Well Harmans are thermostatically controlled, set it, and forget it.

When it comes to heating, the hotter it is, the more heat that is transferred, on the same note, a smaller constant heat, is more comfortable, and you will not cook yourselves out. I do not personally think the efficiency losses of running the Harmans in auto mode, are worth worrying about. If there was more actually scientific proof to back up the argument in either direction, I would give you a straight answer.

I wouldn't worry too much about "over sizing" with a XXV, worst case, you don't turn on the boiler. Also, will your basement get too cold without a boiler running / hot pipes?

It is in my opinion most people who get the 61 or 68 do not need it, but having the option of a roaring fire, is nice.

How much oil did you go through last couple years? You can guesstimate your BTU needs by calculating max BTUs used in the last years. (The coldest year is the best year to go by)
 
Never had a customer say the P43 was to small.

Eric
 
I counted on the basement getting colder. I will probably set the thermostat in the basement to 60 since the heat will only really be lost going up to the rest of the house.
We have only lived in the house for a year. I think we went through around 350 gallons in that time. It was a mild winter though.
Thanks for the help everyone. I think we will go with the xxv. We like the look of it, and it will be advantageous to have a larger stove when it comes time to sell the house. Not everyone keeps their house as cold as we do.
Thanks again. I couldn't have predicted so many responses in such a short time. Looks like I came to the right place.
 
Never had a customer say the P43 was to small.

Eric

My point exactly. If i had to do it over again i would not have gotten the p61. It is too big of a stove and it is in a maintenance burn 75% of the time. It would most definantly been a Harman but not something this big. I have a buddy with an accentra that i might actually work a trade with in the off season. If you have an uninsulated barn in Canada the p61 is great but not in a normal home in a reasonable climate. I can only imagine what the p68 is like.
 
Yep, you did ;) The XXV is certainly the "looker" of Harmans lineup, though the priciest, I believe.

If your basement ceiling is insulated but your walls aren't, most of the heat will be absorbed by the foundation walls. You're saying you have a thermostat down there so my guess is the walls are insulated. Never seen my partially finished basement get below 45 so if you're worrying about freezing pipes, I wouldn't. Just make sure your rim joist is insulated properly and you have frost free sillcocks. If not, slightly pull the insulation away from the pipe. Those insulation dome things work well on the outside.
 
There is a drop ceiling in the basement, and it is not insulated. The walls of the foundation are insulated. We have a theater in the basement, and when we have people over for a movie or football, we turn the heat up in the basement. I can feel the difference in the floor of our main level, so I think most of the heat is going up.
 
Never had a customer say the P43 was to small.

Eric

I will. I upgraded to a P61A after 3 seasons with the P43. The P43 got the area where it's located at warm, but not much else. The P61A is heating 1100+ Sf of a walkout basement that is 3/4 constructed from concrete block. The fully exposed north wall is 2x6 framed with R21 faced fiberglass in the walls. The floor is a slab. There is a lake to our direct north & the wind ALWAYS blows into that wall. It's a cold location in the winter, after the wind crosses that 73 acre ice cube & the P43 just wouldn't keep us warm enough. It does however heat my daughter up in her studio apartment over an insulated garage where the unit is installed...
 
There is a drop ceiling in the basement, and it is not insulated. The walls of the foundation are insulated. We have a theater in the basement, and when we have people over for a movie or football, we turn the heat up in the basement. I can feel the difference in the floor of our main level, so I think most of the heat is going up.
Nice, yer all set then. You pick out an area for your new stove yet? ;)...which you'll love. Your days of 65 degrees may be numbered. Usually works that way :)
 
We have picked a spot. It will be right next to the couch in our great room. We have a friend who will build a hearth for us for only the cost of the stone. It is funny that you referenced the temperature we keep our house. It certainly isn't because we prefer it. I am looking forward to being able stand in front of the stove and warming up.
Thanks again for he help everyone!
 
Welcome to the forum . Nice choice in stoves, you can kiss that 65::F goodbye as reference it's 27::F outside my stove is set @ 4 78::F on 1st floor. Enjoy the heat ;) and remember we need to see pics or it never happened!
 
Good choice on the XXV, I believe it will serve its purpose perfectly.

I will. I upgraded to a P61A after 3 seasons with the P43. The P43 got the area where it's located at warm, but not much else. The P61A is heating 1100+ Sf of a walkout basement that is 3/4 constructed from concrete block. The fully exposed north wall is 2x6 framed with R21 faced fiberglass in the walls. The floor is a slab. There is a lake to our direct north & the wind ALWAYS blows into that wall. It's a cold location in the winter, after the wind crosses that 73 acre ice cube & the P43 just wouldn't keep us warm enough. It does however heat my daughter up in her studio apartment over an insulated garage where the unit is installed...

Just curious, so how were you running the 43? I would the think a 43 running full blast using 3 bags a day would have kept up no problem.

Is your pellet usage up since switching to the 61?

Sorry about the prodding, just interested.
 
Just curious, so how were you running the 43? I would the think a 43 running full blast using 3 bags a day would have kept up no problem.

Is your pellet usage up since switching to the 61?

Sorry about the prodding, just interested.

No problem with the questions. The honest answers are as follows...
The P43 ran the same brand (Cleanfire Hardwoods) & the same amount of pellets 2 bags a day running Stove Temp Hi 24/7 FR 3 & Temp set at 4...It just didn't get the room on the other side of the wall to more than 65 degrees. The P61 holds that room at 69 with the same settings....I've NEVER burned 3 bags a day...
 
No problem with the questions. The honest answers are as follows...
The P43 ran the same brand (Cleanfire Hardwoods) & the same amount of pellets 2 bags a day running Stove Temp Hi 24/7 FR 3 & Temp set at 4...It just didn't get the room on the other side of the wall to more than 65 degrees. The P61 holds that room at 69 with the same settings....I've NEVER burned 3 bags a day...

So was the P43 maxed out at a feed rate of 3? Was there a reason you didn't take it higher along with stove temperature?
 
MightyMoe, it's actually 10 degrees colder here than where you are. Ever since you posted that pic of yer 5 day forecast, I've been mildly intrigued with how cold it actually gets up there. Last week, people at my work were complaining how cold it was. I checked the Fairbanks temp and it was 60 degrees colder there. They still complained 27, or what ever it was, was too cold. Wusses!

I read up a bit on Wiki regarding your weather. Record high of 96. Record low of -62. Incredible!
 
Your basement will get cold(er) not running the oiler boiler down there.
That's why I put a second pellet stove in my basement workshop. The basement got so cold my feet were going numb when I worked down there. With the second stove on a thermostat I can keep the basement at a comfortable to work in 68 degrees.
 
P61 works great in our colonial. This will be my first full winter with it and im estimating 4.5 to 5 tons it will eat.
 
MightyMoe, it's actually 10 degrees colder here than where you are. Ever since you posted that pic of yer 5 day forecast, I've been mildly intrigued with how cold it actually gets up there. Last week, people at my work were complaining how cold it was. I checked the Fairbanks temp and it was 60 degrees colder there. They still complained 27, or what ever it was, was too cold. Wusses!

I read up a bit on Wiki regarding your weather. Record high of 96. Record low of -62. Incredible!

Haha yeah, it was the warmest new years on record, but one of the coldest Decembers apparently -_- I still think 10* windy/humid is worse then -40.
 
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