Water powered dehumidifier?

[The MG Pony]

Ok here on the coast we have a rather nice, albeit small, bakery, they got a bad deal though, I had the stuff to fix a machine and the only way they could pay was with appreciation and food! (and great food it was, I was happy to be able to help) So obviously they can't afford a huge A/C and such.

I was thinking that some old scrap evaps could be easily set to use water to help take the edge off of the place by removing humidity and such. The building (Neglecting the sub roof space) is 12,000CF (340 Cubic Meters)
and for two Air changes an hour I figure a 400CFM (11.3 CMM)Fan would do nicely, and with the city water @ 16c and the ambient air floating from 30c to 20c (Depends if the ovens are running) will give an average of 8c delta or better.

So my question is would this work well enough to bother pursuing? Are my numbers horridly off? Or am I wonderfully happy ignorant of some reason that will make it totally fail all out??

Right now I have not selected any type of coil, I was thinking of using the condenser out of a couple old dehumidifiers who's, compressors have burnt out.

[Brian_UK]

You might get some cooling but I wouldn't think the humidity would change much.

[The MG Pony]

Lol in BC here, it will, I did it at my place with a smaller system and the condensate filled a cooler by the days end, insane levels around here. The main goal is to take the edge off, and see if I'm even close to having my numbers right.

[Dan]

If you have a dew point above the water temperature, you will dehumidify. The more coil surface you have, the better it should perform. If you are happy with a 60 deg C dew point or thereabouts, your idea has merit. But where is the water going, and where does it come from?

I noticed after posting that you would be using city water. Does this mean that you are taking fresh water, running it through your coils, and then dumping it in a drain? If so, your idea has no merit. In fact, I would expect it to be against the law.

[The MG Pony]

No it isn't here (Well not last time I checked), there are some freezers hooked up the same way with water cooled condensers, there is how ever a limit to how much it consumes, hence why I will try and minimize the flow and perhaps even try and make it a closed circuit system with the ability to be refrigerated in the future

I figure I aut to add be for doing any actual building I will be double checking with the building codes people and such.

[star882]

Simply make it a "portable" unit (plugs in, uses garden hose connector or faucet for water). Then it won't be considered part of the building and building codes will therefore not be an issue!

[Dan]

Building codes and laws aside, Clean water is too valuable a commodity to consume for such a meek heat exchange.

The energy being wasted while taking cleaned and filtered water for a single pass through a pipe, then to a drain - just to "take the edge off" far exceeds the energy being saved by using this passive method. Now you could bury the pipe in the ground and recirculate it, perhaps achieving the same water temperature. That would have more merit in my mind.:)

[The MG Pony]

With the amount of rain we get here there are no shortages by fare. Burying it would be ideal but sadly not possible at the location, I will how ever try and see if there are any other ways to do it.

For the same reason why there are no shortages of water are the same reason why evaporative cooling won't work either, the flow rate will be minimized as much as plausible and such.

[star882]

You could direct the warm water to some sprinklers outside to water the landscaping.

[The MG Pony]

Ah there is a good Idea! will try to arrange that! thanks for the idea! :)

[Abby Normal]

Use a swamp cooler, cool/ humidify ambient air, push the heat outside and prevent humidity from building up.

The coast of BC is not really prone to high dewpoints even with its proximity to the Pacific.

16C is almost 61F, not going to pull much moisture out, will lower temps a bit and raise RH. Swamp cooler humidifies outside air, drops its temperature and pressurizes. Room air is forced out of the space taking heat and humidity with it. High relief above the big ovens perhaps.

[The MG Pony]

Some days it is dry, but most our humidity is too high, thats why a Bong type water cooler for PCs won't work well, the Sunshine coast is saturated in ground water, we have natural springs every where so the ground humidity is to high, aside from that there isn't any where to put some thing like that.

If you been here then I'll tell you where it is, it is half way up school hill(Road) right where that old car lot used to be (About a couple blocks down from North road bypass)

[Abby Normal]

Well, I looked at some worst case humidity data for BC and maybe a dewpoint of 62F is it.

ASHRAE deems 60F dewpoint nuetral air.

Relative humidity may seem high, but the actual amount of moisture in the air there is not bad.

I grew up in a high water table area as well, saturated soils etc.

Like I said Pacific NW with is proximity to ocean is not overly humid. Compared to Castlegar or Spokane it would seem humid though, but when looking at dewpoints 62 is not that tough to deal with.

61 degree water won't pull out that much moisture from the outdoor air.