Next question.. chillers

[Siggy]

OK.. next question.. chillers

What is a good brand of chiller? How big of one will I need?

125 gallon main tank
25 gallon sump/fuge (actual water volume.. tank can handle 45 gallons)

400 watts of MH lighting
150 watts of VHO actinic

approx 100 watts of powerheads inside tank
approx 150 watts of external pumps

tank is in the basement where ambient temp stays below 80.

also, can/should the chiller be plumbed in-line with my sump return? or should it be on a completely seperate closed loop?

I've seen some chillers that have dual stage temperature controls.. is it OK to use the integrated temp control on your chiller to also control your heater?

I found a conversion of 1 watt = 3.413 BTU .. excluding the external pumps, this says I would need about 2,218 BTU/hr to dump all the heat from lighting and powerheads.. Do I really need that much BTU, or how much of the lighting doesn't get turned into heat?

also not sure how much cooling I'll be getting from evaporation.

I found a current-usa chiller that does 1400 BTU/hr. I was going to go with this, till I did the above calc..

hrmm.. lastly.. kinda off topic, but I also noticed some chillers can come with modular UV.. is UV really necessary for a reef tank?

thanks,
Dan

[Siggy]

OK.. so I'm replying to my own post.. just some further thoughts..
From what I can find on the net, it looks like evaporating 1 gallon of water should net about 8000 BTU of cooling. Over the 10 hours/day that the MH will be on, this would be about 800 BTU/hour...

so I'm thinking: 2200 BTU/hour in from lights/pumps should about equil the 1400 BTU/hr out from the chiller plus 800 BTU/hr out from evaporation.. (2200-1400-800 = 0) ..

Assuming all my numbers are correct, the chiller would need to run for about 10 hours per day.. Are marine chillers designed for that kind of duty cycle?

Lastly, can someone let me know if I am in the right ballpark with my numbers?

thanks,
Dan

[Siggy]

Bump

anyone?

I'm really interested to know if my thought process in the second post is accurate, or am I just way off base?

Also, does anyone have any experience with the 1/10 hp Current USA chiller?

thanks,
Dan

[Cuby2k]

Well I will take a stab here. I would guess that with the load you have from lighting and the fact that your tank is in the basement, you could very well get by without a chiller.

Make sure you have good ventilation and the evaporation should take care of the load on your tank.

I don't know enough about reef tank chillers to know if they are built tough for the duty cycle you mentioned, but I would think they should be. I mean those hours of operation do not seem that out of line.

Are you getting a great deal on the small chiller you are looking at? The point is if you are paying retail price for a new unit I would hold off first and see if you really need it. If so, go a few extra bucks and get a large enough chiller to make sure it does the job for you.