How Many BTU Pellet Stove for 500-3,000 sq. ft. Homes? (Calculator)
The Pick HVAC pellet stove size calculator gives you an accurate answer to the question – how many BTU pellet stove do I need?
Whether you live in a tiny home or a large home, sizing a pellet stove is easy with the calculator. Use it for stoves or a pellet stove insert for fireplace use. It generates a calculation of the highest BTU rating you’ll want to consider when purchasing a wood stove or insert.
Our calculator also works for the garage, but if you use it to size a garage pellet stove, you’ll likely want to use “Poor” for Insulation Condition unless you’ve wrapped the garage in Tyvek or similar and have insulation in the walls and ceiling.
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Pellet Stove Size Calculator
Here it is. Simple and straightforward. After the calculator, you’ll find a chart where the numbers have been crunched for you. It gives a quick answer to the pellet stove size needed for homes from small to large.
Here are a few notes to consider as you enter information in the pellet stove BTU size calculator. Feel free to skip this section if you know how large your home is and have a good idea of how well it is insulated.
Step 1: Home Size
It’s important to get this right, for obvious reasons. You want the house to be warm without being overheated and wasting fuel cost. This applies to installing a wood stove in the basem*nt, garage or other location.
A “guesstimate” might be quite a bit off.
How big is your home?Many homeowners aren’t quite sure how big their home is. That’s OK. There are places to find the square footage – and worst-case scenario, you can measure and add it up yourself.
A home’s square feetis usually listed in marketing/selling materials, closing documents and on an architectural drawing or blueprint of the house. Perhaps you have one of those docs in your possession?
Home sites like Zillow and Truliamight also have the square footage of your home. Type your address into the search bar on one of those sites, and see what comes up. The sites collect data on a home every time it is put on the market.
Did you have your home built? Call the builder. They’ll for sure know how large it is.
Measuring a home’s square footage:If your home is a simple rectangle, then it is easy. Measure the footprint from outside: Length x width = square feet. If it’s a 2-story home, double the square footage.
When the upper story doesn’t completely cover the lower story, measure the length to where it ends, and use the width from the lower level. Do separate calculations for the lower and upper stories, and add them together.
If your home has a lot of corners, then you’re probably going to have to measure each room from the inside and total up the results.
For each room, measure and multiply length x width to get its square feet. For L-shaped spaces, do two measurements, one for each “leg” of the room.
Step 2: Insulation Condition
Which of these best describes your home’s insulation?
Poor:Older home. The insulation and windows have not been updated. You don’t know if there’s house wrap / vapor barrier under the siding. You might even feel a little draft around windows or doors.
Average:Your home is 15-30 years old. Some improvements like new windows or doors have been made. The attic has up to a foot of insulation. You don’t feel drafts around the windows.
Good:You’re sure your home has a foot or more of insulation in the attic. The windows are newer and designed for energy efficiency. You’re also sure that the house is wrapped in Tyvek or similar material to block air leaks.
Did you know?A tightly sealed home is just as crucial to overall energy efficiency as the right amount of insulation. What good does it do if there’s plenty of insulation, but the warm air from your pellet stove leaks out through unsealed areas of the home, only to be replaced by cool outside air?
Pellet Stove Sizing Chart
This chart gives you quick answers.
| Home Size | BTU Output |
|---|---|
| 500 sq ft | 12,500 BTU |
| 800 sq ft | 20,000 BTU |
| 1,000 sq ft | 25,000 BTU |
| 1,200 sq ft | 30,000 BTU |
| 1,500 sq ft | 37,500 BTU |
| 2,000 sq ft | 50,000 BTU |
| 2,200 sq ft | 55,000 BTU |
| 2,500 sq ft | 62,500 BTU |
| 2,800 sq ft | 70,000 BTU |
Is your home more than 2,800 square foot? Regardless of what heating type you use – gas furnace, heat pump, boiler, etc., a home that large often needs two sources. A lot depends on your climate.
Accuracy Counts!A contractor should do a load calculation to give you specific details on the number of BTUs you’re likely to need to keep the house warm in the coldest weather.
Factors Affecting Pellet Stove Sizing
Home size and insulation quality really are the largest factors affecting how many BTU pellet stove is needed for your square footage.
- Ceiling Height
If you have 10-foot ceilings or a section of cathedral ceiling/vaulted ceiling, you might want a slightly larger stove. One thing we also recommend is to use ceiling fans in these areas – and understand which direction the fan blades should be going when you’re heating your home.
- Basem*nt Spaces
There are specific factors to consider in a basem*nt. First, if your basem*nt isn’t insulated, we recommend that you add something like EPS or XPS rigid foam board to the walls – or else those concrete walls will absorb a lot of heat. If you want a finished look, frame the walls and fill the cavities between studs with the insulation of your choice – fiberglass batts ($), blown-in cellulose ($-$$) or SPF spray foam ($$-$$$).
It will help, too, to staple fiberglass batts into the floor joist cavities overhead to increase the amount of heat staying in the basem*nt. However, if you want the floor above to be warm underfoot, skip the overhead insulation. But your basem*nt might not be as comfortable.
Consider a stove with the highest BTU rating for the basem*nt to be sure you’re as comfortable in the basem*nt as you want to be.
Conclusion
Pellet stoves are space heating devices. Pellet stove experts and, just as importantly, homeowners with pellet stove experience, recommend installing the stove where you want the heat – and don’t expect it to do a very good job heating other floors.
For this reason, most homeowners install their pellet stove on the main floor of the home where they spend the most time – and if they need the basem*nt or upstairs heated, they find another method.
