Back Up Heat Source and Boosting Loop Temps - Page 7

MN Renovator · 04-03-14, 12:32 PM

As far as latitude, Minneapolis is 45 deg N and a quick look at Google maps has it about 50 miles north in latitude so it's roughly the same. The design day temp for Minneapolis is -11F or -13F depending on which edition of the manual J I pick up. This says 7877 averaged over the past 141 seasons. http://climate.umn.edu/text/historical/mspheatdd.txt

So some difference, about 10% more HDD.

His 5 year status report on that page says he consumes 4700kWh of heat, primarily through wood in the masonry heater. Which totals to 16036400 BTU, about 160 therms of natural gas. I would expect a place with R40 walls and an R60 ceiling to perform better than that. Hopefully mine will do better because I'm aiming for about the same values with my own retrofit.

"Had electric baseboard heaters provided this 4700 kWh, at
our current average cost of $ 0.2442 per kWh, the space
heating cost would have been about $ 1,150. It could be
said that the masonry heater currently saves us about $ 850
per year! (and the windows and extra insulation – perhaps
two thousand more!)"

04-03-14, 12:32 PM	#61
MN Renovator Less usage=Cheaper bills Join Date: Nov 2010 Location: Minneapolis, MN Posts: 939 Thanks: 41 Thanked 116 Times in 90 Posts	As far as latitude, Minneapolis is 45 deg N and a quick look at Google maps has it about 50 miles north in latitude so it's roughly the same. The design day temp for Minneapolis is -11F or -13F depending on which edition of the manual J I pick up. This says 7877 averaged over the past 141 seasons. http://climate.umn.edu/text/historical/mspheatdd.txt So some difference, about 10% more HDD. His 5 year status report on that page says he consumes 4700kWh of heat, primarily through wood in the masonry heater. Which totals to 16036400 BTU, about 160 therms of natural gas. I would expect a place with R40 walls and an R60 ceiling to perform better than that. Hopefully mine will do better because I'm aiming for about the same values with my own retrofit. "Had electric baseboard heaters provided this 4700 kWh, at our current average cost of $ 0.2442 per kWh, the space heating cost would have been about $ 1,150. It could be said that the masonry heater currently saves us about $ 850 per year! (and the windows and extra insulation – perhaps two thousand more!)"