greenhouse heaters
 

I am thinking of putting up a 10 x12 greenhouse this year and was woundering what would be the most cost effective heating system for something that big?

i think propane or nat gas are the best systems for heating the standard gh....i use propane, and my gas company gives me an agricultural rate for my gas...ask about it if you go with gas!

I too am starting my research for greenhouses...I am planning on setting one up in a year or two. I have decided I am going to go with a natural gas!

Eric, from the looks of your location, NE, there is much to consider because I'll bet you get cold during the winter... are you using a twin-wall acrylic/polycarbonate or insulated glass? I would assume, like myself located in Michigan, electricity is at a premium cost compared to natural gas which was my choice because you have to "fill" propane tanks and for me that's a royal pain! Also, are you going to go to the trouble of insulating the floor and side walls if you raise the G/H structure up on side walls? I put up an 8 x 15; similar square footage and heat with a 20,000 BTu NG heater purchased for about $225.00 at one of the Big Box Stores; they both sell similar units on a seasonal basis. It has a blower fan and thermostat and very compact. It is non-vented which was a requirement for me because of the G/H I built. If you are building a structure that will accommodate a vented heater, then for sure NG! I do have a 15,000BTu electric heater running on 240W as a backup just in case!

Something else to consider. I don't know if you are building something from scratch or where you will locate your new G/H or even how you will use the interior space, but for me I'd rather have long vs wide because you have to get more than 12' wide to be able to use bench space in the middle.

the one i'm looking at is a twin wall polycarbonate and i don't know if raising it would be good or not i am a framer by trade and would be no problem building anything but i would rather get a kit due to i live right by a walk way and i think if i built any thing they might complain to the home owner sowc i'm sure i will pass it by them but a real green house would be a lot better then another shed or miny house on my property .Is the raised floor better or would it be better to dig 3 or four inches in and gravel it ? i don't know maybe some one could help and i would not mind filling propane tanks but how big and how often are they replaced ?

I was considering heating a house and was wondering how your avoid getting moisture into the heater if you use sprinkler systems or even just a hose to water.....it must be tricky to get a space that doesn't get water.

i would think the heater would dry any moister , but what kind of heater to use is the?

The non vented Blue Flame models are cheap and I use them but they must be replaced every few years as all that I have had rust and the regulators go out periodically. You may instead want to consider one that is built for a greenhouse. They are about twice as much but will last in a humid environment. I have a Reznor vented in my large greenhouse and in the 10 years I have had it I have had to replace the regulator and the burners although they were covered by warranty. I us propane since Natural Gas is not available in my area.

I would go with vented if possible and make sure to get sufficient BTU's. We have had an extended cold period here and mine had a very hard time keeping up.

interesting all this discussion and the differences between "both sides of the atlantic"... I am currently also doing some research for GH heatings, and has been advice that gas should be avoided due to "negative effects" on the plants. Even though electricity should be the NO-NO-NO (due to heating costs) in most of Europe, it seems to be the most appropiate system to be used in France.

I have also been advice to build with a floor digged ca. 50 - 80 cm in the ground, as this would help to regulate temperature (kept above 0°C in winter, but cool in summer)

what i am not very sure yet, is whether the floor should be made out of concrete, or just the ground covered with gravel...

Ramon, wouldn't gas have a negative effect on the plants only if the heater wasn't vented or am I missing something or is there something I don't know about?