Speed of sound and temperature

[keyboarder89]

Hey everyone,

Im doing an experiment with the speed of sound and different temperatures in the air. I am building a box that will have insulation and sound proofing material, and I was wondering if anyone has any ideas on how to keep the box at a constant temperature. I want to heat the inside of the box to 100 degrees F and freeze it down to 0 degrees F. Any ideas other than a heat gun connected to a pipe and a freezer connected to the box? It also needs to make very little noise.

Thanks!

[SY]

Heating is easy- just use a power resistor and control the heat by varying the current or the duty cycle.

Cooling is harder; to get to zero, you'll need some very chilled antifreeze or some dry ice.

[Mr Evil]

Thermoelectric devices (i.e. Peltier heat pumps) can do both cooling and heating just by reversing the current. Nice and simple. With big enough heatsinks it can be silent too (otherwise you'll need some fans).

[454Casull]

Originally posted by Mr Evil
Thermoelectric devices (i.e. Peltier heat pumps) can do both cooling and heating just by reversing the current. Nice and simple. With big enough heatsinks it can be silent too (otherwise you'll need some fans).

What he said.

[SY]

They're cool devices (ouch!), but not cheap.

[Enzo]

Air density varies with temperature, and I would guess that the density will be more of a factor than temperature. Although if you simply want the answer to the question as asked I guess the underlying mechanism is unimportant. But a pressurized test chamber to maintain densities at various temps is probably beyond the scope of this.

[keyboarder89]

Cool, alright thanks for all your help!

Zach

[thomas997]

Originally posted by SY
They're cool devices (ouch!), but not cheap.

ebay has some super cheap ones, but I dont know if I can trust the wattages quoted.