I have a 1600 Sq Ft manufactured home out in the country with a little bit of wind block. Home is 19 yrs old with windows that are mediocre at best. I am running a St Croix Lancaster on a thermostat. It idles on low (1.7#/hr.-9520 btu)then when stat calls for heat it kicks up to whatever I have it set at # 2 (2.25#/hr- 12,600 btu)which is plenty most of the time. It is 14f with a clear sky and no wind and it is keeping up with house at 73f on 2. If it gets in the teens or less and wind is blowing I will have to turn it up to 3(3.1#/hr-17,300 btu) . (5 is as high as it goes. ) I am burning corn so it does not like to go over 3. Pellets it will burn at 4 no problem and I never had any reason to use 5. If it is above 30f or above 25f and sunny, idling on low during the day the house gets to hot. I have to shut it down for a few hours. This is where a Harman or a different stove with smart ignition/tstat would be nice. To be able to shut itself down then relight when it calls for heat. But I get corn for $4.03/bu (56#). Around here pellets are approx. $4.00/40# bag. Calculations done using corn at 7000btu per bu. at 15% moisture and stove efficiency at 80%. Stove may not be that efficient. From experience I have found that my home very rarely requires more that 17,300 btu/hr to keep the home a comfortable 72-73f in central Ohio