the best heating for a greenhouse

concrete slab with radiant tube heating in it….............cant beat it.

-- Central northish Ontario

.... unless the concrete slab cracks. Make sure it has proper drainage under the slab, and the soil under it remains fairly well compacted.

We spent well over $5,000 to put radiant heating into our basement flooring. Then we obtained a special water heater that would handle both the hot water needs of the house, and the radiant flooring. It feels wonderful to be in a place with this type of heating.

BUT … the floor has cracked severely with up to half inch cracks in places. The builder will not assume any responsibility, other than fill the cracks. I have had to disconnect the radiant heating for fear of water running constantly from fine cracks. I have also removed the water heater which was very expensive to run. ... all because of not making sure the drainage was good underneath, and it was packed well enough. I still do have the insulation which does help though. My friend’s place was equipped with the same system, by the same builder, and hers is wonderful. Her house was built on virgin soil. Part of mine have fill under it. That is likely the problem.

So … radiant heating from a concrete slab is wonderful. Just make sure it is done by a professional who really knows the pros and cons of laying the slab.

-- jroot

The sun should provide you with plenty of heat. If the shed is all wood, you could paint the “back” side and/or floor black or any dark colour (sp for all you european influenced north of the states types). In addition, you should consider how you will save that heat with insulation. All the heating is fine in the winter, but, you have to be able to turn it off in the summer, so, adjustable ventilation and/or blinds or shade clothe to cover the windows should be considered.

-- arborial reconfiguration specialist......Zone out....(USA 5)

The sun will provide heat on sunny days during the winter but the temperature will quickly drop starting in the afternoon and overnight without any supplemental heat.
I use different insulation methods in my glass GH and a oil filled electric space heater. I keep a second heater handy if needed for severe cold weather but have only needed a couple times.

Have you read about my GH in the projects forum?

I mention some things like weather stripping, a solar pool cover that covers the building for winter and have some photos of my greenhouse.

http://gardentenders.com/projects/175

Yea, maintenance heat…probably a must. A thermal mass can help store your solar heat so your maintenance heat won’t run as much.

The concrete floor thing would help with that. With the concrete floor I’d probably install the radiant tubing whether you used it or not right away (since retro-fitting radiant in the concrete is…like…a bit difficult [but can be done].)

I think the biggest thing is probably insulation. The better insulated it is, the less heating (and associated cost) you’ll need. That includes insulating the concrete floor underneath. Pay great attention to sealing things up. Your economy will be greatly enhanced.

I like the solar pool cover idea. One of the biggest challenges to home built greenhouses is probably getting so many glass panels sealed from weather [over time.] The pool cover would simply eliminate alot of worries, I bet.

-- arborial reconfiguration specialist......Zone out....(USA 5)

Alot of beer cans, some black paint and a box… Then 2 or 3 50 gallon water barrels inside for thermal mass to sustain night time temps.

http://zedomax.com/blog/2007/04/26/diy-hack-how-to-make-a-solar-heater-under-50-bucks/

http://www.google.com/search?q=solar+greenhouse

-- Planting Daylilies in Kentucky, zone 6b

The beer can idea is good, too. Let me know if you need help with that. It can be a hard task emptying all those cans….but, I’m willing (you are talking about empty cans, right?)

-- arborial reconfiguration specialist......Zone out....(USA 5)

I can help empty a few, also.

-- jroot

lol.. Yeah, empty cans.. You can get temps of 140+ degrees out of the end with a good air flow just from the convection. No fan needed.

This guy didn’t invent the technique. It’s been done for YEARS.. Kind of erks me. At any rate, his execution of the idea is good in function, but also looks pretty. :p

-- Planting Daylilies in Kentucky, zone 6b

Here’s another real good video showing a completed unit.

http://www.youtube.com/watch?v=173owKST-w4&feature=related

And their update..

http://www.youtube.com/watch?v=KBwBxmQ7UDs&feature=related

-- Planting Daylilies in Kentucky, zone 6b

Yes Jim Meady is a Newfoundlander …Cansolair. One unit can heat 1000 sqft in the winter. One unit runs about $3200CDN installed so I am told.

-- Xploreorganics, 5b Canada, LFD 06-20

Yes, but he didn’t invent the technology. ;)

That’s way too much IMO.. I could build one of the same size with little to no problems and at WAY less than that. Especially since he’s using UV stabilized plexi instead of glass.

Regardless. It is a great method of heating.

-- Planting Daylilies in Kentucky, zone 6b

From Szopa to greenhouse

this is the original shed

-- tropicals lover - Katherine, Ontario, Canada (USDA Hardiness Zone: 5a)

From Szopa to greenhouse

this is the “updated” version of it. We are still struggling with the heating ideas. There is an opening left for polycarbonate plexi on the roof which we plan to buy tomorrow. This “structure” has a full wall and half roof facing North and West. It was not debatable as North and West sides have trees which cannot be removed.
Short of more creative ideas we decided to put regular shingles on the roof. Back to the heating – what do we do next? I’ve been leaning towards natural gas garage/shed heater such as big maxx. Space heaters, kerosene, vent free types make me uneasy. Electric heaters would be a killer to pay. I think natural gas is the most cost effective and the safest. The unit is 699 in Ontario (Princess Auto) plus tax plus everything else – pipes, exhaust system, thermostat etc. I’m looking for other unit heaters on kijiji and craigslist so far with no luck.
The shed/greenhouse is already (!) too small too contain all plants which were allowed to grow freely in the soil for the summer. It’s time to dig out Brugmansias (flowering!), Chinese Hibiscus, Musa Basjoos, Oleanders…
Any roofing specialist out there who can tell us if putting insulation on interior part of the roof is a good idea? I say, or, should I say, insist, that it is a must or all heat will evaporate and heat the neighborhood. Any thoughts?
Temperatures are dropping like crazy – in 2 weeks we’ll probably be at freezing. Short of kijiji and craigslist does anyone here have any ideas where else to search for cheaper sources of shingles, heaters, insulation, external panneling and whatever else we could use?

-- tropicals lover - Katherine, Ontario, Canada (USDA Hardiness Zone: 5a)

Updated? There’s nothing left of the original! ;)

Does Canada have a Freecycle type of system that runs? Might check and see, not sure. Here, you can get alot of stuff people give away for free via ads.

-- Planting Daylilies in Kentucky, zone 6b

Yup, here ya go.. Might place a wanted ad, or join and watch.

http://www.freecycle.org/display.php?region=Canada

Freecycle is a simple concept.. You give, you get. Some times hard to get however.. ;)

-- Planting Daylilies in Kentucky, zone 6b

hey, the “original parameters” were saved – that’s what we were told when we called city of Mississauga to inquire about about the house across the street which was raised 3 stories up…
so, we followed the directions: the original base remained minus couple walls and..a bit up..
freecycle – not sure – will check it out – thanks !

-- tropicals lover - Katherine, Ontario, Canada (USDA Hardiness Zone: 5a)

freecycle: we just picked up 100 lbs of nails this weekend. Thank you very much freecycle!! In the past we’ve also gotten a truck load of wood, a truckload of patio stones, and 2 truck loads of new brick. Pretty good, I must say.

-- - Debbie, SW Ontario Canada (USDA Hardiness Zone: 5a)

If you are able to find a gas unit heater, will you be running the gas line to the greenhouse and installing the heater yourself? Or getting a professional to install? Make sure you/they follow the gas codes when doing so…even if you do it yourself, eventually the gas company will be along to change your meter on their preventative maintenance program and will insist on inspecting and relighting all gas appliances. They would be able to tag any infractions at this time and it will end up costing you extra to get them fixed.

Not wanting to act like the “gas police” :)....just want to give you a heads up to save you grief and aggravation in the long run. Since I’ve become a gas fitter I’ve seen some amazing things that people had no idea were infractions and dangerous to their health and home.

I wish I could install gas heat in my greenhouse…but I live in a narrow strip of Ontario with no gas. :(

I’ve been using an electric space heater in my 10×16 GH, along with a clear solar pool cover that covers the whole building in winter plus lots of weather stripping, removable caulking around windows etc.