The truth about BK's

Ah. Well, yeah, that was probably quite a difference.

 

The Princess has about the same usable firebox size as the 30? I didn't know that. In that case I would expect the same "fire power" out of them.

 

I realize that he has plenty of fire power, especially with the insulation upgrades. But he is looking for longer burn times at the same BTU output. My point is (for example) if he needs a 2.85 cuft load in the 30 over 10 hours time, a 2.85 cuft load in a Princess isn't going to last 15 hours in the same location and conditions. For simplicity, lets say 2.85 cuft of wood nets a total of 100,000 BTU's. Stretched over 10 hours thats 10,ooo BTU's per hour, perfect. If the same load is stretched over 15 hours, thats only 6,666 BTU's per hour. If you need 10,000 per hr, 6,666 BTU's per hr isn't going to cut it.

 

"About" would be a good estimation. The edge would go to the 30 most likely, but the heating capacity would be about the same. Probably about the same as the Defiant, also. The Defiant has a big firebox but it is curved and not square or rectangular so you lose usability on each side. It is really hard to pack the Defiant tightly.

 

1950's single level 1900sqft. Little insulation in the attic and none in the walls The last cold spell I burned to full loads and a 4-5 split load per day with a walnut honey locust mix. Lows varied -2-10° highs never made it to 30.

 

I didn't see that, thanks for sharing.

 

If the Mansfield keeps up fine, a BK 30 would probably keep up just fine. The Mansfield is advertised at 3.2 cuft, have you measured the usable firebox?

 

Let me explain a bit better. Let's say the Steel and the Princess both offer blowers. The Defiant does not have a particularly efficient cat system. If I could have the Steel or the Princess sit at 450-500 with a blower, those stoves would be just as effective at giving me the heat I need while being a boat load more efficient than the Defiant since it likes to temp climb.

The 30, as non-cat stoves tend to do, peaks at 650-750 in temp. At those temps I can get the room to 85+ degrees in most weather conditions. Which is a waste of heat. The 30, when run at 200-400, can keep the room at 75-80 during most temps.

 

Based on the Heritage's firebox (which was actually below 2 cu ft compared to the 2.3 it was advertised as) the Mansfield is probably in the 2.5-2.75 cu ft area base on what I saw when I nearly bought a used one. Hearthstone stoves are quite liberal with their firebox measurements.

 

It seems to make sense, but I have not seen a Princess in person. So, take it with a grain of salt, but it makes sense to me. Hopefully I'll find out within the next year or two.

 

Good points, unnecessary temp spikes waste heat. Ya'll are bringing me around.

 

True but what I'm trying to wrap my head around currently is with my stove I run the temp up to the low 80's due to the heating curve. How much heat is lost due to this vs. a constant 75-78 through the house.

 

2.8 usable is what I've come up with. I think the square shape helps to keep it closer to advertised.

 

Good point, unnecessary temp spikes waste heat. Ya'll are bringing me around.

 

Do have to push the Mansfield at times?

 

Okay. Seems about right.

 

FYI, I helped a friend add 8" on top of the existing 4" in his attic recently, roughly 1800 sqft. I think he said the insulation cost $550 at Lowes, free blower use with purchase, only took a couple of hours and he said it made a big difference in wood usage and comfort. It's cheap and easy to make a big difference in most attics.

 

Remember, if you do not oversize and need to run the stoves harder, you are absolutely correct that you will not see much benefit from the BK system since running at the lower temps will not provide enough heat.

What type of burn times do you get from the Keystone?

 

This is what I did. I will be adding more this spring to be sure I am at R-60 throughout 75-80% of the attic.

 

I wouldn't say I'm pushing it now that I'm burning truly dry wood. But what does that really mean? 2 years ago I sure felt like I was.

If I switch I want to be on an easy 12 hr load cycle when its cold.