Does anyone have opinions on the use of a heat pump for controlling room temperature. I am setting up a fish room and the greatest problem will be heat generated by the pumps and lights.

May have 4000 litres in the end so a chiller is not a practical option.

Best bang for the buck would be opening a window and putting a fan in front of it...

I used to have a fishroom,heavily insulated with no windows, 12ft x 8ft and and a light over every tank (about 50), heated by a one kw element and a fan going all the time and heat was never a problem. Unless you have massive lights in which case I would confer with the previous advice about diverting the heat away. Don't forget you are paying for heat even if it comes from lights, so if you can use it to preheat water you may save a bit.

I think his problem will be keeping things cool, not warm.

It depends how much heat u r trying to get rid of. If its a small amount and really the heat pump is just taking the edge off it, its a simple way to have good temperature control in the room. Expensive capital wise, but then relatively cheap to run, especially if it doubles as heating in the winter.

If you think the pumps and lights will be generating some serious heat, a heat pump could become very expensive way of keeping the room cool though.

U could look at using a simple thermostat to open a vent and start a fan. I would think a bathroom fan(or home ventilation system) set up on a thermostat would do it? I would tend to look at setting it up to blow cool external air into the room rather than suck from the room to external though.

Suggestion... set up the room first. If it runs warm try a ventilation system from Bunnings (it should cost <$250 for a single room one complete with thermostat control). If it cant keep it cool in the summer then look at the heat pump. If are also needing heating during the winter the room then a heat pump looking a good option. Capital wise it would still be the most expensive way to go though (even compared to say 50 tank heaters @ $25= $1250)

Yes the problem will be keeping things cool not warm. I figure that if I can keep the air temperature down and stable then the water temperature will stay stable as well. Perfect application for a chiller but that is not practical for a system of this size.

The room is on the north side of the house so the exterior wall gets a lot of sun. The room will be well insulated so the exterior temperature should not be much of a factor.

Whangaparoa I doubt gets much above 25-27 C. That says to me that if u have enough external air flow (venting) u should be able to avoid a heat pump.

Basically a big vent, and fan on thermostat will be cheaper to install and run than a heat pump.

I will look into the vents. I could suck cooler air from the basement, through the fish room and then outside.

Heat pumps are getting much cheaper. The Warehouse and Foodtown now sell them. Foodtown had one for $649.00.

Agree they are getting heap cheaper, the cheaps one tend to be noisy which I guess isn't a problem in a fish room. Plus the installation costs are still the same, normally round $500-$600 I understand.

I just worked out how to do my cooling system today. Was working on something else (data cable in the house) and the solution for the tank cooling became obvious.

Basically the problem was in summer:

Outside of house during day very hot (sun trap), night time cool

Basement of house day time cool, night time hot

Fishroom between the two.

I got a temp controller of Jetski awhile ago (will even pay for it at some stage ) so I am going to plug fans into the cooling side. I will also put them on timer switches so during the day only the fans bringing air in from the basement will work and at night only the fans bring it in from outside will work. That way the air coming in will be the lowest temperature available. I was trying to get super technical and all I need is timer switches!

Wonderworld Pet Centre had a similar problem in their shop. They fitted a large extracter fan with variable speed controller in the ceiling. This is a very cheap option, and filtered intake grills are available cheaply from Bunnings.

BSG