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Peltier dehumidifier Answered

I hope someone with a technical background can help me with this...

I am trying to make an DIY dehumidifier. The goal is to lower the humidity
of my room during the summer months (humidity is around 70% at 25C) to
less than 50, preferrable 30%.

I have the following setup in mind:

To achieve condensation I want to use a peltier that will lower the temperature of an radiator.
The condensed water will be gathered in a (plastic) box. This water will then be used to cool the
hot side of the peltier, using a water block and a waterpump that was left over after using watercooling
on my PC.

The image depicts an simple graphic of the setup.

However, I have the following questions to be answered:

- How cold (relative to the ambient temperature) would the cold-side radiator have to be to get optimal condensation
- How much watts of cooling power would the peltier need in order to achieve the needed temperature difference
- If i lower the cold side temperature with 20C, how much heat would be generated on the hot side? (my gues: 20C,
but im no genius ;) )

Thanks in advance!


After your comments I have been working on testing my idea's...

based on the instructable:

a have picked up some copper piping, and created the set up like in the above instructable. The tub holding the water was filled with cooling elements and bottles of frozen water from our freezer.

With water about 8C colder than the ambiant temperature in my room, I got quite some condensation from the copper pipes, which have a limited surface compared to a real radiator i'm planning to use.

SO now im thinking about turning it around: keeping the peltier outside cooling the water, and cool the peltier with outside air.

2013-07-20 17.00.14.jpg

Just wondering if you have an update on this project? I currently live in a rather humid climate and it's truly aggravating to deal with. I nice home-made using would be awesome :)

I am waiting for parts to arive from china to the netherlands... free shipping... so it can take up to three weeks to arive!

Update: I have ordered a peltier and other components to further test the setup
( https://www.instructables.com/id/Homemade-air-conditioner/ ). I'll be back once they arived and had a change to test the setup.

I suspect this would not make a good dehumidifier. For one it may not get cold enough to effectively pull moisture out of the air. It may take several coolers to be effective. You'll also need a good strong fan to help circulate the rooms air through the cooler to effectively remove the moisture. The biggest problem is efficiency. To create a system like this that is as capable of removing the moisture as a typical vapor-compression dehumidifier it will use much more energy to do so.

Here give this a read it should help. It's in relation to CPU cooling but still applies.