Drolet ECO-65 BTU efficiency ratings?

[hyfire]

Hi the manual says 7.9lbs/hr and a 65000 BTU rating. The wood pellets I am using say 8400 BTU/lb. If we do the math this comes up 66360 BTU's. This unit is rated at 77.8% efficiency how do come up with that number? If I'm putting in 66360 and getting out 65000, that is like 98% efficient, or am I missing something here?

 

[smwilliamson]

Efficiency is heat transfer to home vs up the stack. Most BTU ratings assume 8k per pound, though there are some pellets that burn closer to 9k.

 

[hyfire]

Thanks, I can get some 9000 btu pellets that would put me at 71100 btu in theory I guess?

 

[IHATEPROPANE]

Thanks, I can get some 9000 btu pellets that would put me at 71100 btu in theory I guess?

6.9lbs/hr x 9000btu = 62,100 BTU per hour....

62,100 x .77% efficiency = 48,000 output btus assuming the efficiency rating is correct

 

[hyfire]

6.9lbs/hr x 9000btu = 62,100 BTU per hour....

62,100 x .77% efficiency = 48,000 output btus assuming the efficiency rating is correct

That is a good question, how can they advertise the stove as 65000 BTU then, that won;t cover my needs on a cold day? at 48000...I made a mistake its rated to burn 7.9lbs/hr@ max setting, not 6.9 lbs

 

[IHATEPROPANE]

That is a good question, how can they advertise the stove as 65000 BTU then, that won;t cover my needs on a cold day? at 48000...I made a mistake its rated to burn 7.9lbs/hr@ max setting, not 6.9 lbs

Not sure where you are from by I live in southern central mass. My stove is capable of 70k btus according to the manufacturer. I never run above level three which is roughly 4.5 lbs per hour and even then it is cycling between 1and 3. Coldest days about 2.5 bags or 100lbs a day or 4 lbs per hour. This is on the coldest days warming a 2000+ sq foot with average to below average insulation. I use 5.5 tons per year and pellet heat is probably 95% of my heat needs

 

[DexterDay]

Input BTU = 65,000

Output BTU = depends on install, pellets burned, and how clean stove is kept.

A stove that large should handle most heating needs. I used a Quad Classic Bay (47,500 input BTU) on its lowest setting for several years and I have a home that is just shy of 2,200 sq ft. The house, the location, insulation, pellets burned, cleanliness of the heat exchange system, and overall convection of the home all go into account,,

Can you give us more info on your home? Sq footage, how many levels, how old, insulated well, cathedral ceilings, etc...??

 

[smwilliamson]

Any input BTU rating assumes biomass at 8000 BTU's