DIY Hood w/ lighing & refigum

[kimf]

I want to build a new hood for my reef tank.
Thinking two sections. Lower section for lighting solid divided between upper and lower section. upper section with gravity feed return refigum.
Do you think keeping lights on refugim 24/7 will effect the heat of the tank?
Do you think the heat from the lights in the lower section would be a problem for the refugium?

 

[captained]

How much heat transfer is a good question.. I'd like to know the answer myself. I wonder if anyone has a formula for calculating how many watts it takes to raise the temp 1 degre per gallon?
Based on the recommended wattage of heaters, it looks like 2 watts would raise the temp 10 degrees per gallon, but that assumes your lights are in the water and there and no fans. I'd guess a 20% transer at the most, so that works out to about 1 degree per watt per gallon. If you have 800 watts on a 120, then that makes 6-7 degrees.
OK, I have no idea if that is a good formula, but it seems like a reasonable guesstimate anyway.

 

[dwf]

i don't know the formula but when i put 4-98 watts above my 90, it raised the temp by 4-5 degrees. I had to get a chiller which is doing a good job.

 

[wallda]

Kimf and CaptainEd, I will be returning to my University later this week. I will go and talk to my Heat Transfer Professor and find out some info on the subjet of Watt vs. Temp increase. Just so I have some info to go in with, what distance from the top of the water will the bulbs be located? Also, a fellow mechanical engineer and I are starting to build/design custom hoods so this will work out great for us!
Daniel
wallda@uwplatt.edu