Winter Greenhouse Heating Ideas

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
When 100*C steam changes to 100*C condensate it gives up 2142 btu’s per 1000 g’s. …the original phase change energy transport material - unless the definition is expanded to include wood as an energy transport material with phase change to high temperature plasma, lol.

For comparison, do you know the mass of the 400 btu tiles? Couldn’t find the mass on the web page?

The first sentence is Greek to me.

Mass, not sure.

I do know that Ceres Greenhouses, one of the premier 4 season solar greenhouse companies in the US uses Insolcorp's Phase Change Material in their greenhouses.
 
  • Like
Reactions: Stove Cricket
I was giving this some thought. The DIY treatment have you. Anyone know the latent of coconut oil. That was the only thing that make to mind. I’m sure there are other materials. I was trying to come up with some better ideas. But wall of water was all I could do. Like a bottle wall.
 
  • Like
Reactions: Dan Freeman
I was giving this some thought. The DIY treatment have you. Anyone know the latent of coconut oil. That was the only thing that make to mind. I’m sure there are other materials. I was trying to come up with some better ideas. But wall of water was all I could do. Like a bottle wall.

Don't know about coconut oil, but that is an interesting idea.

Some PCM's use Paraffin (like the wax in automatic greenhouse window openers). The wax in the automatic opener's piston heats up and liquifies, it expands the piston, and the window opens. At night, the process reverses, but when the liquid paraffin solidifies again, it gives off heat. This is good for both the summer (helps cool) and winter (helps heat).

There are other PCM's but paraffin is the one I am most familiar with. I don't even know what the "ingredients" are in the ones I just ordered. If Ceres Greenhouses uses them, they have to be outstanding, so I ordered them. All I could find on the website was: "Our PCM’s are non-toxic, safe, have high density and are abundant in nature."
 
Don't know about coconut oil, but that is an interesting idea.

Some PCM's use Paraffin (like the wax in automatic greenhouse window openers). The wax in the automatic opener's piston heats up and liquifies, it expands the piston, and the window opens. At night, the process reverses, but when the liquid paraffin solidifies again, it gives off heat. This is good for both the summer (helps cool) and winter (helps heat).

There are other PCM's but paraffin is the one I am most familiar with. I don't even know what the "ingredients" are in the ones I just ordered. If Ceres Greenhouses uses them, they have to be outstanding, so I ordered them. All I could find on the website was: "Our PCM’s are non-toxic, safe, have high density and are abundant in nature."
Soy based wax/oil???
 
This brings up a question for me. Is the shape of a greenhouse important or make any difference? I can get the peaked roof style, or the domed style. I assume the only difference is aesthetic, or vertical space along the walls.

Does it negatively or positively affect sunlight within the greenhouse at all? Which one would you choose if you had two options (Also, the domed ones are cheaper)
 
This brings up a question for me. Is the shape of a greenhouse important or make any difference? I can get the peaked roof style, or the domed style. I assume the only difference is aesthetic, or vertical space along the walls.

Does it negatively or positively affect sunlight within the greenhouse at all? Which one would you choose if you had two options (Also, the domed ones are cheaper)

In my experience I have never come across any information on the advantages of one shape over another when it comes to sunlight (PAR energy), although I have read of deep solar greenhouses where they talk about the pitch of your glazing for the most solar gain (both PAR and warmth). There is little leeway in roof shape when buying a pre-made greenhouse. With that being said, choice is usually a matter of taste, opinions/concerns about snow and wind loads, or an incidental factor when buying a specific greenhouse for specific reasons other than the shape.

For me here in PA, one of many reasons I purchased the Mt. Rainier in 2015 was because it has a steeply sloped roof and it sheds snow easily, a concern here in the Pocono Mountains (although not this year!). The biggest factor was that I was one of their online dealers at the time, and I got a deal I couldn't refuse!

I chose the Riga for numerous reasons (the price was not one! whew!). I do like the roof shape (onion) for snow shedding and wind loads, although wind load is secondary. We do get high winds at times, but my greenhouse is pretty well protected between 3 buildings and a hill.

So, long story, short, roof shape should not be the determining factor but one of many. You'll never buy the "perfect" greenhouse. There is a lot of give and take in the whole process.
 
  • Like
Reactions: clancey and RomanW
RomanW--You'll be in good company with freeman for he likes to research too so the two of you will be "twins of knowledge" concerning these different types of greenhouses.. I applaud this..clancey
 
Would the optimal angle for solar gain be the same as what you would want for solar panels? (Latitude?)

The steeper the walls, the easier they’ll shed snow.
 
  • Like
Reactions: Dan Freeman
Would the optimal angle for solar gain be the same as what you would want for solar panels? (Latitude?)

The steeper the walls, the easier they’ll shed snow.

Good point. I would imagine so. From my limited knowledge on the subject, I believe solar panels are set to get the best "average" over the entire year, no?
 
I’d think so. I imagine, given the option, the panels would be more vertical when the sun doesn’t get as high.
 
Kind of lost here are you too talking about movable solar panels or do they have that already?? Really stupid on this subject so be kind...lol clancey
 
Much has happened since I wrote yesterday, and we have decided to move earlier, rather than later on the greenhouse, because of this...

I heard back from Site Prep LLC this morning. To install a level 14 x 20 pad with 4-6's anchored into the ground with rebar and 4" to 6" of tamped gravel in the middle on top of weed barrier is going to cost $2310. I don't think that is bad at all, and I don't have to buy and lug the 4 x 6's or the gravel or do any of the site/base prep. For me, that is worth it. It comes to $8.25 per square foot.

I remember leveling the 8x16 when we built it, and the 8x10 first chicken coup we built a few years earlier. I remember all that work just too vividly! You get tired real fast as you lift large 4 x 6's in and out of the foundation as you adjust, adjust, adjust the gravel to get it level. I found it back breaking 8 years ago; I can't imagine doing it now.
 
  • Like
Reactions: clancey
That sounds like a real decent price for a site prep and its the beginning on your planned greenhouse ----glad you are not doing that type of work by hand---and your ribs could not take it anyway.....You just "go for it"...clancey
 
  • Like
Reactions: Dan Freeman
Well... I think I've changed my mind after some research lol. (@Dan Freeman That fault we have, ya know?)

I think I'm going to look into using ICF for the foundation, and insulate the 4 feet under the house, and use a the framing from an already existing building I have to build a 16x16' house off of the south wall of my garage... That will cause me to not have to build a 4th wall, and I think I may sink the GH into the ground a couple of feet, and make a sunken GH...

Thoughts? I'm thinking of doing a bunch of stuff this guy has done. I may not be able to make it tropical in there in the winter, but it should at least help widen my growing season, and if I'm lucky... grow some winter crop in there.

 
  • Like
Reactions: EbS-P
I have watched that video before. He has some good ideas.

Sounds like a good plan. I look forward to hearing about and see pics of your build as you move forward.
You and me both.

Has anyone ever tried that terracotta heater idea? I know it's some big TicTok idea, and I hate fads...

But if it works...
 
  • Like
Reactions: Dan Freeman
You and me both.

Has anyone ever tried that terracotta heater idea? I know it's some big TicTok idea, and I hate fads...

But if it works...
Have you check the price of crisco? I’m sure it’s much cheaper to run an electric space heater. FAD.

He’s got some good ideas but is execution is flawed.
It’s just like a house. Air seal, insulate, insulate, insulate, the ground source heat is good but expensive.

I think all his black weed barrier is silly. But it make work. It’s going to have to have supplemental heat. Store it water tanks insides. If I were in a cold climate I would do this.


Reasoning. Space, and cost. bury the tank at least partially. The ground source is good but it’s going to be a pain to construct in some places. He said he dug down 6’. I missed what he filled it back with. Construction

Anything north of say 45 degrees is going have very different heating needs.
 
I've seen both yea and nay on the terra cotta heater.

I tend to be a skeptic.

What I don't buy is the terra cotta somehow makes tea candles heat a space any more than if you burned the candles without the terra cotta. A tea candle only produce a certain amount heat energy; putting it in terra cotta cannot increase its heat energy.
 
Spent a good part of this afternoon cleaning one of my greenhouse recirculation fans. First thorough cleaning, other than a quick brushing after last season, that it has had. I dissembled it as much as I dared, and it looks like new.

BTW...take it from me, do NOT go cheap on your greenhouse fans, exhaust or recirculation. I've even had two fans from one of the most popular brands out there and both only lasted a year. Don't buy plastic if the fan is going to be running a lot and in a moist environment (like in a greenhouse!). Invest a few bucks and buy a good greenhouse fan.

My present fan, more than two years old, is from J&D Manufacturing and is a waterproof fan. I run it 24/7 from March until November. https://jdmfg.com/product/indoor-ou...recirculation-fans&application_cat=greenhouse

My exhaust fan, exhaust shutter, and intake shutter for the new greenhouse will also be J&D products and will be controlled by a thermostat that will coordinate all three motors to tun on/off the fan and open/close the two shutters.
 
Have any of you read the Nearing's books on their greenhouses in VT and ME? They fed and sustained themselves with homebuilt, stone greenhouse structures.

 
  • Like
Reactions: Dan Freeman