DIY Chiller or am I crazy?

[Chin_Lee]

I've had this idea but never had the chance to test it out so I'll post it to see what you DIY guys think.
Since the seawater starts to freeze around -2C, i figured why not use a small chest freezer instead of a bar fridge. I believe that freezers have a more power compressor than a bar fridge so if thats true, then the plan is as follows:

1) Get a small (or whatever size you can accomodate) chest freezer off the buy&sell
2) find a BIGGEST container that can fit inside the freezer to occupy the most space inside the freezer
3) throw in 50 feet or so of 3/8 or 1/2 inch plastic tubing and space them out as much as possible inside the container
4) drill through the freezer wall and plumb plastic tubing through
5) plumb the other ends of the tubing into your sump
6) attach two pumps to one end of the tubing
6a) pump A will be a small pump to keep the water in the tubes moving and will be on constantly to provide a very slow flow through
6b) pump B will be a bigger gph pump on a thermostat to turn on when you want to start cooling
7) fill the container inside the freezer with water
8) add auto antifreeze into the water
9) put a small powerhead into container of water to keep water moving
10) set your freezer to around -5C or so

You will probably have to play around with the freezer settings, temp of antifreeze and the small pump setting until you get the desired effects.
The antifreeze will stop the container of water from turning into block of ice and the powerhead in the container will keep maximize heat transfer from the tubing
During the day when the heat rises, it will transfer the heat into the container of antifreeze through the tubing and the freezer may or may not have to run as much as a bar fridge.
Overnight, the freezer will bring the antifreeze back to -5C.
The small pump will keep the water inside the tubing from reaching below -2C
I have no idea if antifreeze will ever leak through plastic tubing - but I'm sure somebody out there will know. Considering antifreeze is stored in plastic containers thats thinner and softer than the tubing that we normally use, i believe it will be safe.
You can probably even store your frozen fish food in the freezer if its strong enough.

This is just an idea that I've been throwing around for a while so give it a try if you think it will work for you.

CWLee

[StirCrazy]

Originally Posted by chin_lee

I believe that freezers have a more power compressor than a bar fridge so if thats true, then the plan is as follows:

nope not really, they are designed to operate at a different temperature but still have a low duty cycle.

Bar fridges, full size fridges, freezers ect all have motors with very low duty cycles as they are not designed to run much. to get something with a decent duty cycle you are looking at more than it would be to buy a chiller in the first place.

now if you want to look into a home made chiller, start looking at window ACs hooked to a heat exchanger. you will need some one who is certified to do refrigeration work to plumb it and in the end it might save you 100.00 on a chiller (unless you already have a AC you can use)

Steve

[Chin_Lee]

I guess that puts my idea down the drain ...... thanks a lot steve

[Willow]

when your talking about a freezer surely it would be cheaper to think about a chiller?

[cc_bruno]

Here's a link to a DIY article that you might find helpful:

http://<a href="http://www.aloha.net...iller2.htm</a>

Seems like it would work just fine, but, not having built one myself, I can't speak from experience. Hope it helps, though.

Robert

[Chin_Lee]

Originally Posted by Willow

when your talking about a freezer surely it would be cheaper to think about a chiller?

you can buy used ones for cheap in the buy and sell. i've seen them for 50-100 bucks! But if the compressors are not any different, probably won't work anyways.

[snaggle]

Here in Alberta it might work better then other places because it gets colder at night I think if you tank is in the basement it would help. I would use the whole fridge including the freezer part turned all the way down on a timer that has a random setting so it will turn on and off and not burn out the compressor. That is just my two cents I am going to run an apartment sized AC in my room this summer to keep the heat down. Also remember that chillers and bar fridges kick out a lot of heat so that will bleed in to the room and in the end might just kill all the effects of having it in the first place.

Brad

[StirCrazy]

Originally Posted by cc_bruno

Here's a link to a DIY article that you might find helpful:

http://<a href="http://www.aloha.net...iller2.htm</a>

Seems like it would work just fine, but, not having built one myself, I can't speak from experience. Hope it helps, though.

Robert

they will work good for minor temp drops (usaly about 1 to 3 degree drop in a smaller tank) concider I am droping my temp 16 degrees in the summer with a small chiller.
the part that they are not good for is the fridge motors will have to run more than there made for and burn out. how long 1 year maybe 2 maybe more. but you won't much more than that.

Steve

[cc_bruno]

Good to know. I thought about building one as well, but, didn't notice any temp spikes in the summer, (the tank is in the coolest room in the house), BUT, I was not running MH bulbs either, (will be running 3 - 4, 400 watt ones this summer... but, the tank will be much bigger, so, we'll see if I'm going to have to buy a chiller this summer ).

Robert