Greenhouse heat

Garden Forum » Greenhouses in the Garden Forum » Greenhouse heat « Previous    Next »

Author Message   Jak3  My Weather Posted on Saturday, February 15, 2003 - 04:58 am EST :    I live in a very cold climate and cannot use my greenhouse from November to February because it is too cold. What type of heating do you use, pros and cons? Julie; Merrickville, Ontario, Canada, Zone 4   Gardenbug  My Favorite Photo My Weather Posted on Saturday, February 15, 2003 - 05:54 am EST :    Julie, I am cheating, because I don't have a greenhouse. I use a back room for my plants and seedlings. Because this room is heated by electricity, we tend to keep it at about 10-15C most of the winter, rather than 20C like the front of the house. In fact, we have been keeping the front of the house at 15C also this winter and using our wood stove in our large family room. We'll see how the fuel bills compare. I actually enjoy sleeping in the cooler temperatures. gardenbug Ontario, Canada zone 5b, USDA zone 4   Monique  My Favorite Photo My Weather Posted on Saturday, February 15, 2003 - 06:05 am EST :    I can just imagine what everyones bills will be like this year. One thing about being a realtor I don't like is the fluctuation from one uear to the next cost wise. Clients inquire about.. say.. the last 2 yrs(Which had been tame here) and then are so surprised when the bills of a really cold year like this one..are so high. I would rather buy roses too ! Mnique Québec Zone 5   Cahenry  My Favorite Photo My Weather Posted on Saturday, February 15, 2003 - 08:36 am EST :    Julie, we got a natural gas, unvented heater, from Lowes. It is plenty adequate for the size of my greenhouse 8 1/2 x 12 1/2 and out temperatures. It has gotten down to 6\char(deg}F once this winter and the teens several times. Mostly it stays right around freezing overnight. It get so warm during the day (many days) I have the door and vents open. cahenry (Cathy) GA Zone 7   John_ny  My Weather Posted on Saturday, February 15, 2003 - 11:30 am EST :    I have 200 BTU, oil fired hot air furnaces, and I'm really taking a beating, with the very cold weather, and the high oil prices. John_NY USDA6/7, Sunset34   John_ny  My Weather Posted on Saturday, February 15, 2003 - 03:47 pm EST :    Sorry, a little goof on the last post. That should read 200,000, not 200. John_NY USDA6/7, Sunset34   Diveanddig  My Favorite Photo Posted on Monday, February 17, 2003 - 09:15 pm EST :    Julie, I have a 10x15 ft attached greenhouse. The five feet nearest the house is set back into an existing recess formed by the house, so it has a roof and two sides for that portion. Ten feet protrudes out from the house. The greenhouse has about 500 gallons of water in containers that acts as a passive solar heat source. Water has a high heat capacity and absorbs excess heat during the day and radiates it back during the night. We had an old fashion radiator installed under a center bench and ran another hot water zone off the house furnace. The thermostat is set at 50 F. A large ceiling fan installed to the existing roof overhang runs constantly at low speed to circulate the heat throughout the greenhouse. Bill Bird - Westchester Co., NY - Zone 6   Jak3  My Weather Posted on Tuesday, February 18, 2003 - 03:52 am EST :    Thanks all. Bill, is your greenhouse double-walled glass or acylic? Mine is unfortuately only single pane plate, so the heat loss is enormous. But I would really like to do something so that I don't lug 50 plants into the basement every fall and back out every spring. My greenhouse is about 10 x 16 and is 11 feet high at the highest point, where it attached to the house. Julie; Merrickville, Ontario, Canada, Zone 4   Karmahappytoes  Posted on Tuesday, February 18, 2003 - 07:43 am EST :    Wow it was great to read all of this and to know I'm not alone in taken a big bite in the wallet. We have an older fiber glass pre 1950 9 X 12 footer with wood frame greenhouse. Since the fiber glass is old we have lined the inside with clear plastic and bubble wrap. During the winter months we also use a blue tarp to cover the whole greenhouse. We use 2 portable heaters on the floor level with a fan up top to circulate the air flow. We do keep tropicals in there so our range of heat is 65-70. The over flow of plants about 1,000 give or take a 100 are currently in our home! If prices keep going upward I'll have to move another kid out the door! Karmahappytoes   Gardenbug  My Favorite Photo My Weather Posted on Tuesday, February 18, 2003 - 08:48 am EST :    Welcome Happytoes! gardenbug Ontario, Canada zone 5b, USDA zone 4   Diveanddig  My Favorite Photo Posted on Tuesday, February 18, 2003 - 08:48 pm EST :    Julie, My attached greenhouse is a Northern Light greenhouse and is a double walled plastic film with about 1/2 inch distance between sheets. Ice damage and age has damaged the biggest south facing surface and I replaced that surface with double wall lexan sheet. You can find insulating solutions for your glass greenhouse at Charlie's Greenhouse Supply. See their web site. They sell a special large plastic bubble sheet that will attach to the inside of your glass. Also, you can use the aluminized bubble sheet insulation on surfaces that get little or no direct sunlight. Most heat loss is radiant heat loss so the aluminized sheet will help in that regard. It is available at Charlie's or Home Depot. You can also use 55 gallon black plastic drums as bench supports and water storage. I found someone on the web who gave me 8 of those beautiful drums. The passive solar heating at night helps a lot. I found that electric heat was barely adequate and very expensive. Bill Bird - Westchester Co., NY - Zone 6   Bonitoad  Posted on Wednesday, February 19, 2003 - 12:11 am EST :    My greenhouse is 10x16, plastic corrugated roof and heavy plastic (don't know proper name)panelled walls. It has a cement raised bed at one end ( U-shaped). This is where my Pomegranate tree lives. For the past 2 yrs. I've run a heat coil through the bed for the cuttings I've started. The tender plants were dug into the soil but , now they all just sit on top...nice and toasty. My only heat source is a brooder light... turned on in Nov. until the end of Mar. I also use bubble wrap ,during these months , where needed....to fill in any gaps. Uses hardly any hydro...bulb lasts for 3 yrs. If I'm working at the other end...potting up etc...& get cold I just stand under the lamp. I just realized...I should hang a lamp at that end too....I'll get one tomorrow...thanks for asking the question..... Bonitoad Canada Zone 7b   Jak3  My Weather Posted on Wednesday, February 19, 2003 - 04:07 am EST :    So it seems like bubblewrap is a good first step, and portable heaters are the next. Bonitoad, what is a brooder light? Sounds like a farm chicken thing of some kind. If that is the case, I could probably round one up as I live in a relatively rural area. I also use big black drums of water as supports. My greenhouse sits on a big insulated box filled with chunks of granite. there are pipes running through the granite and cinderblocks with the holes facing upward around the edges . We have a pipe running part way up to the top with a small fan attached so that warm air from the top can blow down through the granite all day, heating it up. In the fall the floor is nice and warm in the evening as the stone slowly relaeses heat. We also have a raised bed all around the greenhouse foundation, so the earth there helps. I want to get started now for next winter; I tend to over-plan, I guess! Julie; Merrickville, Ontario, Canada, Zone 4   Jak3  My Weather Posted on Wednesday, February 19, 2003 - 04:12 am EST :    BTW, I had a guest speaker at my garden club meeting on Wednesday; the topic was seed starting. He suggested that, if you want bottom warmth for your flats, not to buy the real expensive heat mats, instead use the low voltage tape that you would wrap around pipes to keep them from freezing. DH bought some of this yesterday and I will be trying it out this Spring. Someone also suggested using the cables that you put on your roof to prevent ice build up. This would probably work, but the voltage is a little higher and I would probably want it to sit on a non flammable surface. Just a tip. Julie; Merrickville, Ontario, Canada, Zone 4   Bonitoad  Posted on Wednesday, February 19, 2003 - 06:36 pm EST :    Julie... you're right.. a brooder light is low heat bulb in a reflector..used to keep the little chicks warm.... very inexpensive. I had to ask my DH ( he's from Ont. ) about cables ' to prevent ice'.... they sound similar to the cables I use in the raised beds. Last year I used borrowed heat mats.....glad I didn't buy them... wasn't impressed. Anyway... Happy Gardening.... Bonitoad Canada Zone 7b   David_b  Posted on Thursday, February 27, 2003 - 06:36 pm EST :    Does anybody know anything about the hot water, radiant, floor heating systems that are used for greenhouses and also for some in-home applications like bathrooms? We were thinking about building a new house 10 years ago and has specs for a greenhouse, and the architect had recommended such a system as the best, most efficient for a greenhouse. And it gets pretty cold where I am so if I were really going to put up a sizable attached greenhouse I would want to spec this in. Anybody know? David Michigan Zone 5-6   Jak3  My Weather Posted on Thursday, February 27, 2003 - 07:50 pm EST :    Don't know much but we are investigating this now in order to install radiant floor heating in a slate floor in our kitchen and bathroom. I will let you know when we have more info - about a week from now I hope. Julie; Merrickville, Ontario, Canada, Zone 4   Diveanddig  My Favorite Photo Posted on Friday, February 28, 2003 - 08:01 am EST :    David, I would think that heat would be lost to the soil with heating coils embedded in the floor. My attached greenhouse has a big old cast iron radiator that is heated with a hot water zone from the house. It is under one of the tables and heat is circulated with a fan. Bill Bird - Westchester Co., NY - Zone 6   Lynnflower  Posted on Friday, February 28, 2003 - 10:08 am EST :    Had under floor heating installed a few years ago - just in the part of the kitchen that was bumped out to put in frenchdoors and that did not have a basement under it. Kitchen floor is stone so it can be hideously cold in winter and the heating does work when turned on - but I claim it causes a brown out for 6 blocks in every direction when I turn it on. Furry slippers might be better. (Rabbit, Gardenbug?) Re greenhouse - mine is attached to the house and the hot water heating pipes from the house also run through the greenhouse. They are rather huge and unsightly so I had covers made to hide them - but they do work. Probably an inefficient method as the windows are original and single pane. lynnflower Ontario USDA zone5 and USDA zone 4   Taryn  My Weather Posted on Tuesday, March 04, 2003 - 05:19 pm EST :    Hi everyone, Julie, I have an 9 X 12' detached, single-plate glass greenhouse too, that DH built me. It is to be a 3 season greenhouse only, as it would just be too prohibitive to heat year round. In the fall I got a great deal on Ebay for a 30,000 BTU non-vented heater, brand new, for $100.00US. Even with the shipping, duty and taxes, it was well below the $700-800CND a new heater would cost locally. My gas guy was going to install it for me in January, then in February, but we've cancelled both times, ironically because it was too bloody cold! Not being an emergency or anything, I told him to save it for when it gets reasonably (as opposed to ridiculously) cold, probably later this month, as I'm sure not about to fire it up when it's -29C (-20F) like yesterday! For now, I have 3 four-tube growlights plus a few smaller flourescent tubes for starting seeds in the house. But I will be out of space soon, so I sure hope it warms up soon! If you like you can see some pics of my GH here: http://www.picturetrail.com/gallery/view?p=999&gid=238126&uid=107739 Taryn Taryn S. Ontario zone 5 US/6B CDN   Jak3  My Weather Posted on Wednesday, March 05, 2003 - 04:43 am EST :    Oh Taryn, what a great gallery! We didn't have a camera when DH built our "labour of love/project from hell" *LOL* so you photos brought back a lot of memories. Do you have your water lines from the house? We just ran a line from the eavestrough into a large barrel mounted on a bench, and put a faucet into the barrell. We have an overflow hose out into the garden. I have found that I have enough water and it is natural rain water, good for the plants. Cheap and easy! I will get DH to keep checking ebay - he just bought a guitar that way - to see if we can find a heat system. You can see my greenhouse on the thread "Why I am looking for heat". Julie; Merrickville, Ontario, Canada, Zone 4