Chuckie,
I think your problem may be a heater that is too small. According to the
heating calculator at http://www.littlegreenhouse.com/heat-calc.shtml , you
will need 30,000 BTU to heat your greenhouse on a typical coldest zone 5
night of -15F to an inside temp of 70F. this is assuming that you have the
greenhouse with the inflated double polyethylene roof and sides.

If you are growing anything other than warm weather crops , like tomatoes,
or tropicals, you can get away with 40-45 temps if you use rootzone heat of
some sort.

In iehter case, a larger heater is needed

Virgo91967


"Chuckie" wrote in message
oups.com...
I am hoping to grow plants with hydroponics starting in January. My
problem is that my greenhouse does not hold heat very well. I have
tried methods like hanging fans from the ceiling to pull the heat back
down to the floor. This works but not well enough if it is 30F outside,
the house is at 55F.
I have no duct work run because of my limited budget. I have the house
insulated. It has a 10000 BTU propane heater and it seems that all of
the heat escapes out of the top of the greenhouse. It is a clearspan
greenhouse.
I need to reside at 70F.
Any suggestions would help.
Thanks
www.clearspan.com
www.teksuppy.com
www.farmtek.com

All or nothing is the wrong approach.
Chuckie in the frozen north zone 5