I’m looking to FINALLY make the leap into getting my greenhouse heated. I’m in zone 6b and have an old Lord and Burnham partially underground greenhouse from the late 50s. It’s old obviously and the glass isn’t the most heat efficient. I’m looking into getting a modine HDS 45,000 BTU propane heater to heat 1/2 of the greenhouse. Anyone use this one to heat their greenhouse? It was recommended to me by L&B. For those that have propane heaters did you have a plumber tie it into the gas line? Would appreciate any and all advice- especially if you have a similar sized propane heater would love to know what your propane costs are $$ 😅
by elle1369
2 Comments
I heat with propane, however my greenhouse appears to be much smaller than yours. I pay about 20 bucks to fill a 20gal.tank
I am in 6b also with a small 12×14 hoop house, I was able to keep in it in the 50’sF when it was 11F outside using a 4500/9000BTU buddy heater. My hoop house is sealed pretty well so the O2 depletion senor shuts the heater off after 3-5 hours. A twenty pound propane tank lasted about a week running heat around 12hrs a day.
This was roughly $2-3USD day to run. Uhaul in my area is $3.99per gallon of propane, with roughly 5pounds ~ 1gallon.
I switched to a ” cheap diesel heater” two weeks ago running the heater over nights keeping an average of 60-65F, if the forecast cloudy and below 30f I will turn it all the way down and let it idle while at work. (the last overcast day was 22F outside and 72F inside with the heater idling to hold 47F).
The heater is marketed as an 8KW heater, but content creators on youtube have ran timed tests and calculated that only 5KW of the 8KW energy is actually converted into usable heat and the remainder is wasted through the exhaust ( there are methods to capture some/ most of that wasted heat).
The daily cost to run the diesel heater is roughly $3.50 a day. With diesel roughly $3.75 a gallon but I am looking to run waste vegetable oil blend to stretch out the fuel costs.
My reason for choosing the diesel heater were that combustion gas intake and exhaust is routed outside of the hoop house minimizing risk of carbon monoxide and reducing condensation.
For mathing
1KWH~ 3412 BTU
1gallon of propane is roughly 91,500 BTU /cost 3.99
1 gallon of diesel is 138,700BTU /cost 3.75
1 gallon of kerosene 135,000 /cost 12.99
[https://www.acfgreenhouses.com/greenhouse-heater-size-calculator.aspx](https://www.acfgreenhouses.com/greenhouse-heater-size-calculator.aspx)