How to Build a Constant Temperature Chamber?

[0omnidirectional]

How would I go about building some sort of chamber that keeps a temperature constantly in the 70 degree F area?

[Mantikore]

details please

how big, what purposes etc.

and use insulation :)

[Christ puncher]

My fish tank does exactly that, its got a heater in it which is a glass tube with a dial on top I set it to keep the tank at a constant 74 degrees, it turns on when the water is to cold and shuts off when the water is warm enough. You need a heating a cooling process. Get a electric heater with a thermostat and a electric fan with a thermostat set them both to 70 degrees with the heater on intake and fan as exhaust. After contemplating this a bit more, you could rig both heater and exhaust fan to run from one thermostat that would probably be located in the heater.

[0omnidirectional]

16'' high, 24" long, there abouts.
Purpose: mycolgical experiments.
My surroundings can be anywhere from 75 - 105 degrees, with 0 humidity.
I have plans for humidity that shouldn't be a problem, but the temp makes the environment go all out of wack. I'm trying to produce an environment similar to their natural habitat.


So an aquarium you say? I could fill it only halfway right, and have my experiments floating on the water, or connected to the side? I already have an aquarium heater, could you please explain more about the electric fan?
I found this on amazon for 53% off:

http://www.amazon.com/Marineland-PFES12-Seamless-Integrated-Aquarium/dp/B0002APZWQ/ref=sr_1_1?ie=UTF8&s=home-garden&qid=1242850132&sr=8-1

That would be awesome if there were plants and fish moving around it there.

[0omnidirectional]

I've been thinking.

I was thinking of making 2.5 gal spawn bags, and once they're ready to fruit, I could put the bags in a cooler with the bottom 3.5 inches filled with water and an aquarium heater set to 70 degrees.

[Sentinel owl]

You can use a bimetallic strip and a control circuit. http://en.wikipedia.org/wiki/Bimetal_strip

A bimetallic strip is basically two thin sections of different metals connected together. Different metals expand differently with temperature, so if one expands more than the other, the strip curves. So what you want to do is to attach power to the bimetallic strip, and have a contact on either side of it like this:


0..||..0
....||
....||
....||
....||

so what happens is this: when it's too cold, the metal bends one way and completes a circuit, turning on a heater. When it gets too hot, the strip will bend the other way and connect the other contact, completing a circuit to a peltier cooler or something.

You can also look into using mercury switches to accomplish the same task.

In any case, you'll have to do some trial and error to get your temperature range set correctly. I'd make the electrical contacts screws that you can adjust in and out to get your desired temperature range.

[comrade george]

You can use a bimetallic strip and a control circuit. http://en.wikipedia.org/wiki/Bimetal_strip

A bimetallic strip is basically two thin sections of different metals connected together. Different metals expand differently with temperature, so if one expands more than the other, the strip curves. So what you want to do is to attach power to the bimetallic strip, and have a contact on either side of it like this:


0..||..0
....||
....||
....||
....||

so what happens is this: when it's too cold, the metal bends one way and completes a circuit, turning on a heater. When it gets too hot, the strip will bend the other way and connect the other contact, completing a circuit to a peltier cooler or something.

You can also look into using mercury switches to accomplish the same task.

In any case, you'll have to do some trial and error to get your temperature range set correctly. I'd make the electrical contacts screws that you can adjust in and out to get your desired temperature range.

Wouldn't this mean the temperature would go up and down periodically?

I would set up two circuits, one connected to a cooler and the other to a heating element. Using thermistors and transistors so that they come on at fixed temperatures and will operate at different levels depending on the ambient temperature, rather than a binary system with the bimetallic strip.

[Zip]

I think you're putting a little too much thought into this.

Styrofoam insulation should be more than adequate, you could also make a basic alarm from a K-type thermocouple to make sure the temperature doesn't go out of the specified range, if you have a newer DMM (Fluke, Agilent, etc.) it's an inexpensive accessory.

[Sentinel owl]

Wouldn't this mean the temperature would go up and down periodically?

I would set up two circuits, one connected to a cooler and the other to a heating element. Using thermistors and transistors so that they come on at fixed temperatures and will operate at different levels depending on the ambient temperature, rather than a binary system with the bimetallic strip.

Yes, but it will be within a specified range. It's a very crude solution, I'll admit.

[Mantikore]

in that case, its pretty simple. just use a thermostat to regulate temperature, then use a fan to ensure even heating.

with the fan, you can control humidity as well, so thats a plus when it comes to growing mushrooms