Gas Heating Vs Hot Water Piping underbench

[OzPhal]

Hi everybody,

I'm currently scoping out a design for a glasshouse heater system at the moment - everything is in the planning stage so i have no firm dimensions etc currently. What i am working with at the moment is the heating for the glasshouse. I want to grow primarily Phalaenopsis and i live in southern Australia where it can get quite cold at night. I have heard varying stories about using gas heaters etc and i am leaning more toward the 'old school' method of circulating hot water from a boiler through a network of pipes... what are peoples thoughts on this? Is it easily controlled? pros & cons etc any system recommendations?

[orchids3]

Gas heat simple but you must make sure you have enought ventilation - gas buildup from the pilot light can cause all the buds to drop. Have been around Hot water and steam - good heat but more complicated. It does have the advantage of retaining some heat even if the boiler goes out which gives you time to correct the problem. An alarm that warns of low temperatures is a wise investment no matter what type system you choose.

[dounoharm]

ditto on the alarm system for temps....its a must have! i have had a gas heater in my greenhouse for 3 winters now and no problems....i have never had the pleasure of working with a hot water system so i cant advise on that.....gl....

[richardb]

I too have had a gas (propane) heater for many years. Nowadays it is used as backup for my electricity. I have had no problems whatsoever, but have been very careful to provide ample air to the burner. Some people think that providing ventilation loses heat, but hopefully people do not seal their greenhouses in the winter anyway. Certainly a gas heater would be cheaper to install than hot water pipes, and the boiler for the pipes would be quite costly too. If you opt for a propane system do make sure that you hitch up TWO tanks with an automatic changeover valve - you do not want to run out of gas on a cold night. Not sure what part of Australia you are in, so your heating requirements will also depend upon the drop in temperature you need to cover and the perceived timescale during which you will need to provide heat. If you have only a couple of months cold enough it seems hardly worth the expense of a hot water system. The more you spend on heating the less you will have to spend on plants!
Richard