How to heat your greenhouse cheap

tvaughan · Post by **tvaughan** » Sat Mar 29, 2008 9:45 pm

Well, not too cheap, since you've got to put several hundred dollars into it, but as far as long term cheap heat, here's what I came up with. The trial and error cost me more stress than you, dear reader, need to go through. But this worked all throughout this last year, and it cost about one dollar per day in extra gas bills during the cold part of the year, from October to March.

You take a gas water heater like the one you have in your house and put it as close as you can to your greenhouse. If it's farther than a few yards, no big deal, but you'll have to insulate the lines. Then run a closed loop from the water heater and back again. The loop is made of your choice of plastic tubing. The loop goes along the shelves, by the base of the plants.

Here is the pipe by some carnivorous plants and orchids

tvaughan · Post by **tvaughan** » Sat Mar 29, 2008 9:50 pm

Then, somewhere in the loop (it doesn't really matter where) you put in a pump. The pump circulates the warm water from the tank through the pipe/s and back into the hot water tank. You can see it's now disconnected for the summer:

Then, you hook up the pump to a thermostat, so the pump is only working when the temps drop to the danger level:

Simple, cheap and elegant. Not that getting gas and electricity to your greenhouse is always the easiest thing on earth, but I trust you all get the idea.

tvaughan · Post by **tvaughan** » Sat Mar 29, 2008 9:54 pm

I used regular drip tubing, and it heated up the area around the pipe to about a foot on the sides, and a couple feet above the pipe. The tallest of my Nepenthes tropical pitcher plants died back or died altogether every year until now, and that's about 3 feet above the shelves.

ihc6480 · Post by **ihc6480** » Sat Mar 29, 2008 10:01 pm

Sounds like you came up with a fairly easy heating system. Only question I have is how much water did you loose in the tank due to evaporation and such or did up have a supply line hooked up also to top the tank off occasionally.

tvaughan · Post by **tvaughan** » Sat Mar 29, 2008 10:14 pm

Very good question, Bill. While thinking it through, I also was VERY worried about running an expensive pump dry. So I put a tee in the loop, with a valve, and every couple days I opened the valve (which was above the level of the whole system) and topped off the water.

And here is the panel, which runs the RO water, misters, thermostat etc... (yes, I built it myself so no comments about a lack of professional tidiness.

ihc6480 · Post by **ihc6480** » Sat Mar 29, 2008 10:16 pm

No comments from me. OK, I lied

but the comment is "If it works like you planned than it's a job well done"

Post by **daiv** » Sun Mar 30, 2008 2:07 am

Nice Tim. I'd bet that you could get some radiators that have fins on them etc. for radiating the heat even more effectively. I don't know how well that will work in Central MN, however.

MichaelCactus · Post by **MichaelCactus** » Sun Mar 30, 2008 5:51 am

Wow, you certainly know what youre doing! Now if i only the gas connected to the house i could do it

lordarutha · Post by **lordarutha** » Sun Mar 30, 2008 6:12 am

The victorians only had manure to play with to keep their greenhouses warm in the winter (so I have read) any one know how that works?

Tim, that looks great.

tvaughan · Post by **tvaughan** » Sun Mar 30, 2008 1:37 pm

The problem with radiators is that you want to heat the least area possible! Just a foot or so around the plant and a few feet above it. I probably have only 3-5 percent of the greenhouse heated, which is why the gas bill only went from our base rate 30 dollars.

Post by **daiv** » Sun Mar 30, 2008 1:43 pm

tvaughan wrote:The problem with radiators is that you want to heat the least area possible! Just a foot or so around the plant and a few feet above it. I probably have only 3-5 percent of the greenhouse heated, which is why the gas bill only went from our base rate 30 dollars.

Got it!