Calculating square footage for heated area

[tsh2002]

Hello,
We are looking at installing a wood stove later this year in a new home. We narrowed our stove choice down to the Blaze King Ashford 30, which is rated at 1100-2400 sq ft, however we were recently told it might be "too much" stove for our home and maybe we should instead consider the Ashford 20 (which looks to be rated at 900 - 1500 sq ft). We are in lower Michigan, in the winter our lower temps can reach around zero, but normally it is around 10-20 degrees.

Our home is newly built in 2019, with good tight insulation and 2x6 walls. The stove will be located in the main area near the center of the home, which is about 940 square feet of open space. About half of this area has 8 ft ceilings, and the other half where the stove is, is vaulted up to 12 ft. We have a ceiling fan up there to help circulate. When adding in the other side rooms (all with 8 ft ceilings), that are separated by hallways/doors/etc, the total square footage is around 3000. We are hoping to heat as much of the home as possible in the winter, so I'm open to using fans, etc to do that.

So now the question is, does the square footage recommendation by the manufacturer usually include just the main area where the stove is located or should we be adding in the extra rooms as well? Mainly just trying to determine which of the Ashford 30 or 20 is a better fit for us.

Thank you very much.

 

[ABMax24]

The BK users will be along shortly. Moral of the story is the difference between the 20 and 30 is not the heat output on low (they both run almost the same), but rather how long the stove can burn at that low output setting.

If you want the 30 then get it, really no downside to it over the 20.

 

[Rickb]

The BK users will be along shortly. Moral of the story is the difference between the 20 and 30 is not the heat output on low (they both run almost the same), but rather how long the stove can burn at that low output setting.

If you want the 30 then get it, really no downside to it over the 20.

This..... I love my 20. But I have a small area i am heating. And Even with the 20 I very rarely fill it full. Usually unless its sub 15f out I only load 3 or 4 splits at a time and my stove is set to low 80% of the time.

 

[begreen]

Both models are thermostatically regulated and have a similar heat output on low. The Ashford 20 sounds like it will do the job here and costs a bit less. For even lower, continuous heat output there is the Woodstock Fireview.

 

[tsh2002]

Thank you for the replies so far and good info. So just to confirm I am following correctly, should we be factoring in only the square footage of the main area where the stove is located, or should we also factor in extra rooms that we could also try heating (with a way to get the air flow to them)?

 

[begreen]

It's kind of a moot point between the 20 and the 30. They are both thermostatically regulated, the 30 just has a bigger fuel tank.

 

[Ashful]

It's kind of a moot point between the 20 and the 30. They are both thermostatically regulated, the 30 just has a bigger fuel tank.

Yes, this.

But I will add a few small points:

1. If the low burn rate works for your winter heating needs, then this could be an ideal match. But if you think that a continuous 30 hours at a low burn rate is going to suit you in shoulder season, you might want to think again. It's common in the warmer months to want some overnight heat, but to have the stove go out during the day, to avoid getting the house too warm.

2. The Ashford 30 can achieve cat light-off on loads down to about 30% to 40% of firebox capacity. Trying to run the thing with any load less than 30% of firebox capacity is an exercise in frustration, and inconsistent cat light-off. I honestly expect nearly all cat stoves share in a similar limitation, proportional to their size.

So, the minimum output setting on the Ashford 20 and Ashford 30 may be very similar, but it's very likely the 20 can do that on shorter loads, for shorter durations, if that matters to you.

 

[Ashful]

I guess I should have added that this comes from experience running two Ashford 30's, in very different settings. One stove is in a large stone wing of our house, residing on the second of four floors, comprising about 4000 sq.ft. and 1 million pounds of exterior-exposure stonework. The other stove resides in a modern framed and glass addition, with 14 ft. vaulted ceiling and a space of perhaps only 1500 sq.ft.

In winter, we run 2 full loads per day in the first stove, and 1 full load per day in the second. The thermostats are adjusted to burn these full loads down to coals, to be ready for an easy reload and nearly constant heat around the clock, at their respective rates.

In shoulder season, I run 1 full load overnight in the first stove, and a partial load overnight in the second. I use roughly the same thermostat settings as when running in winter, such that both are pretty much burned out after ~14 hours.

When it gets real cold, I'll often push three loads per day thru the stove in the stone house, just running one of these loads (usually early morning) at wide-open throttle, going from full firebox to coals in ~4 hours.

 

[tsh2002]

This is all extremely helpful, thank you! Yes, to answer the question on the shoulder season, that is very likely the case here as well. So that alone might sway the decision. We like the fact the 30 can run longer, but having that extra flexibility of the 20 makes sense.

 

[Hoytman]

Both models are thermostatically regulated and have a similar heat output on low. The Ashford 20 sounds like it will do the job here and costs a bit less. For even lower, continuous heat output there is the Woodstock Fireview.

Care to explain what you mean here about the WSFV versus the 20?

 

[Ashful]

Care to explain what you mean here about the WSFV versus the 20?

Yeah, I'm confused about that, too. Woodstock is a great company, and they make great stoves, but they're not achieving the 10 hours per cubic foot burn rates that BK can get down to with reliable precision. I've never heard anyone choosing Woodstock over BK, on the basis of lower burn rate capability. Usually it's a cosmetic decision, desire to try soapstone, or preference to deal directly with mfg. over dealers, which has people looking at Woodstock.

 

[begreen]

Look at the EPA test results. The Woodstock Fireview has a notably lower, tested, EPA output as compared to the Sirroco 20, @ 7,606 BTUs/hr vs 8,900 BTUs/hr or about 15% lower. Several years ago there was a lot of discussion about the Fireview's ability to comfortably heat smaller spaces including one owner who provided a fair amount of detail on this.

 

[Ashful]

Look at the EPA test results. The Woodstock Fireview has a notably lower, tested, EPA output as compared to the Sirroco 20, @ 7,606 BTUs/hr vs 8,900 BTUs/hr or about 15% lower. Several years ago there was a lot of discussion about the Fireview's ability to comfortably heat smaller spaces including one owner who provided a fair amount of detail on this.

Definitely. But haven't you also said in other posts that the EPA test results are a very poor indicator of real-world operating range? I'm really just basing my assumptions on burn times I remember people posting in the past. That might all be a bit subjective, but it seems like a reasonable metric, for this purpose.

Also not trying to discourage anyone from Woodstock, they're a great company and great stoves, by all accounts. I've just never heard anyone citing them as the solution for those wanting absolute maximum burn time or lowest output.

 

[begreen]

Definitely. But haven't you also said in other posts that the EPA test results are a very poor indicator of real-world operating range? I'm really just basing my assumptions on burn times I remember people posting in the past. That might all be a bit subjective, but it seems like a reasonable metric, for this purpose.

Also not trying to discourage anyone from Woodstock, they're a great company and great stoves, by all accounts. I've just never heard anyone citing them as the solution for those wanting absolute maximum burn time or lowest output.

EPA testing can be a poor indicator of the maximum output capacity of the stove, especially if burning hardwood. That's quite different from the low end output which should be fairly accurate. Real world usage results will always be somewhat subjective considering the variables involved, but the BK and Woodstock EPA testing is under the same standard lab test criteria.

 

[Highbeam]

The EPA tests, flawed as they may be, are the closest thing we have for an apples to apples comparison. The fireview is not thermostatic so holding that low output for a full load may require careful fiddling.

 

[Todd]

The EPA tests, flawed as they may be, are the closest thing we have for an apples to apples comparison. The fireview is not thermostatic so holding that low output for a full load may require careful fiddling.

I don’t think they’re allowed to fiddle with it during the EPA test. That low output should be an average of the lowest setting output for a single crib wood charge I believe.

 

[Hoytman]

I don’t think they’re allowed to fiddle with it during the EPA test. That low output should be an average of the lowest setting output for a single crib wood charge I believe.

Correct!
Just normal stove operations to get wood charred and catalyst ignited, then possibly 1-2 small adjustments to get to low burn over a short period of time at the front of the butn cycle. Rest of the time I don’t believe they touch the controls until reload. At least that is what I observed WS doing while performing their own mock epa test.

Crib wood and/or cord wood.

Perhaps I’m mistaken but I don’t believe so.

 

[joop]

crib newone on me?

 

[Hoytman]

crib newone on me?

Here you go. Take a look. The EPA just recently (last few years) started testing manufacturers stove models via “cord wood” testing which is supposed to be more realistic for the homeowner/stove purchaser.

Cord Wood and Crib Wood Testing | US EPA

the differences between testing cord wood and crib wood for emissions limits

www.epa.gov

Cord Wood vs Crib Wood Testing Explained | Regency Fireplace Products

Learn the difference in EPA testing methods and why it matters.

www.regency-fire.com

 

[joop]

seems logical.if wood is tested for moisture content and species