How to heat a green small greenhouse.

Ridgerunner

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On regulating the heat from a heat lamp, use the right wattage bulb. They are hard for me to find in a hardware or feed store, but you can get 75, 125, or 250 watt bulbs. In winter when brooding chicks I use a 250 watt. In the heat of summer I use a 75 watt. You can also adjust the heat by moving the heat lamp closer or further away. To me a very important safety consideration. Throw that clamp away and use wire or chain to hold it in position. Do not use string or plastic that can burn or melt, use metal. And do not depend on that clamp, that is an accident waiting to happen.

I have not tried putting a dimmer switch in the circuit. Theoretically that should be another way to adjust the heat but I don't know how well it works in practice.
 

Dirtmechanic

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I have about 5 of these heaters. I like them because they are about as safe as possible. One can easily heat a room, but with the built in thermostat and remote control its about as easy as it gets to set and maintain a temp. They are 99 on sale now that the season is ending. They can run 1500 watts so a regular 15amp circuit works. I can heat my 2 story house with a generator, and not use them all.


1360375.jpeg
 

catjac1975

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Check your wattage on the brooder light.

When I used one - really, not that long ago - I remember having problems with the temperature in the box with the chicks. (I wonder what I did with that thing 🙄.) Anyway, the last few times that I have bought chicks from the feedstore - I found out about their last deliveries from the hatchery. Then, I put a nice little set-up ... in the greenhouse! By the time that their later shipments came in, the greenhouse was warming nicely through the days. I set up a "fake hen" in the box ;). It was a board covered in shag carpeting with very short legs attached. It sat on a nice warm blanket. The chicks could crawl under the board, which they did! Between the shag carpeting and the blanket they kept themselves warm :).

@catjac1975 , I looked back in this subforum 5 years but realized I could just do a search for "building greenhouse" ;). Here is the one I was thinking of: Feb 28, 2012

Steve
YES!!! I knew someone could find it. I did a search without your luck.
 

digitS'

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I would like to know something about the heat retention of water.

We read about people using barrels of water in a greenhouse. Surely, there is a way of measuring how well that works, or might work.

Here is a little bit of an addition to that. Aquarium heaters are not terribly expensive. Even those of 500 watts cost only about $100. They are designed to warm an aquarium that would be waaay too big for nearly any homeowner. Probably, a barrel might be okay. A stock tank is another $100+.

At one time, I felt that there was far too much use for the area under the center bench in my greenhouse. Plants were fairly happy there and had enough sunlight. With less garden space to fill with plants, the area under the bench could now hold a couple of barrels or stock tanks. Might be approaching a $500 investment but that would still be less than having a new gas heater installed. And, there might actually be an energy savings.

Steve
 

Dirtmechanic

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I would like to know something about the heat retention of water.

We read about people using barrels of water in a greenhouse. Surely, there is a way of measuring how well that works, or might work.

Here is a little bit of an addition to that. Aquarium heaters are not terribly expensive. Even those of 500 watts cost only about $100. They are designed to warm an aquarium that would be waaay too big for nearly any homeowner. Probably, a barrel might be okay. A stock tank is another $100+.

At one time, I felt that there was far too much use for the area under the center bench in my greenhouse. Plants were fairly happy there and had enough sunlight. With less garden space to fill with plants, the area under the bench could now hold a couple of barrels or stock tanks. Might be approaching a $500 investment but that would still be less than having a new gas heater installed. And, there might actually be an energy savings.

Steve
Water loves heat. Witness the Carnot cycle for making electricity with steam, and this graph of solar energy, the valleys of which are caused by water vapor and other gases in the atmosphere absorbing the energy from the sun.
insolation_curve.jpg


My question would be the extraction. A heat exchanger with a fan seems the only way to control humidity inside such a heated space.

edit: I know two engineers that measured the solar spectrum and its more 49vis/49ir with a sprinkle of uv for garnish heat. 44/53 is internet truth so be it.
 
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flowerbug

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barrels of water can get warmed up, especially if you have them painted black or they are made out of black plastic.

the hot water heaters for such would be ok, but any cords would need to be heavy duty and subject to random damage so always a consideration.

you can pick up a lot of heat from the ground and store it too using a smaller wattage fan to move the air instead. so what that ends up being is a geothermal heat pump type of system. that is possible fairly far in the north but you'd need a site that can do that. here it won't work. :(

what i've wanted to do was put some large water tanks in the crawl space and then use the sunlight and solar hot water heating to grab the extra heat when it is available, this extra heat could be used to pre-heat the hot water system but also to supply some extra heat when it is available. if using electricity to run the pumps as those are only needed when the sun is out you can size the pumps and have those matched to solar panels to drive it all. when the sun isn't out the pumps aren't needed. if you have a cold enough climate that freezing is a consideration you can set it all up to drain back when the pumps aren't running and the sun isn't out. a fair amount of complexity but probably would pay for itself in less than ten years and perhaps even quicker if your electrical provider is at the higher end of the range in price per kwh.

once you have a few hundred gallons of hot water sitting someplace that is a lot of stored heat and thermal mass. in the summer use it for a hottub. :)
 
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