Question
I live in a mountain community and have a 8 x 14 hobby greenhouse for orchids.  I am currently heating it by a direct vent wall furnace 25,000 btu propane heater.  With the cost of propane, I need to find a more efficient and economical way to heat my greenhouse.  In the winter we have a lot of 10 to 20 degree nights and 30 degree days and my heat is on 24/7 and the cost is about 600 dollars a month.  I need to find a more cost efficient way to do this.  I am looking into radiant heating but I am not finding the right information.  Can you make some suggestions?  Bonnie Whitman

Answer
Bonnie, the first thought that came to me has to do with heat conservation.  If you have single pane glass, you could install bubble pak insulation on the inside of the glass.  It just installs with water or a special bubble insulation spray adhesive.  As a first cut, try this and see what your energy savings is.  Another, more expensive, route is to replace the glass using polycarbonate glazing. In the latter instance you could then place bubble insulation on the inside of the polycarbonate walls.  I have had good success with supplies from Charleysgreenhouse.com.  They have all of these materials.  In addition, for a modest amount, you could obtain a programmable thermostat to adjust the temperature at different times of the day and days.  These additions alone should pay for themselves in a few years.  In addition to these energy savings features, you could choose to place removable insulation on the north wall in the winter time. You should be able to obtain these and other ideas from Charley's Greenhouse catalogue.

I operate my greenhouse when winter temperatures often drop well below zero.  The first four feet of the greenhouse is below ground level and well insulated.  I have coverted to the polcarbonate and bubble insulation and am pleased with the energy savings.  I set the programmable thermostat to 53 degrees on Saturday and Sunday nights and to 60 degrees during weekdays to help save energy.  I also store water in 55 gallon drums.  This helps to lower heating costs in the greenhouse by storing heat both from the heater and from the sun on sunny days.