cooling for tank with canopy

Thanks to everybody for the great info. I just pulled the canopy out of the box and measured the opening:12"*40". Not sure how I came up with the earlier measurements (oops). So now I'm thinking (with all your input) to mount three our four fans in the back pointing in. Maybe even rig up two different circuits and have two kick on when temp reaches 80, the other two at 80.5. I want to be prepared since the sump will be no help with cooling.
P.S. The cat decided to check things out from the inside for me.

 

No need for so many fans.
My 100 G tank has a totally enclosed canopy all sides, top and back, with only two 4" low speed Vantec Stealth fans, one in each end. Until recently the lighting was 2x250w MH and 2x140w VHO actinics running 10 hrs a day in Phoenix AZ in a home with a digital setback thermostat on the AC so it is warm during the day when we are at work. The tank stayed 79-81 year round with no chiller and the fans running at reduced speed on a variable voltage DC power supply set at 7.5 or 9 volts.

The canopy is 60" long by 18" front to back and 12" high and with two Vantec Stealths gets 2-3 complete air changes per minute which is more than sufficient to carry the heat away. The added benefit of having the fans on the ends and the exit holes in top is it cools by natural convection even when the fans are not running, you can actually feel the heat rising out the top when you hold your hand over the exit holes with no fans running.

I switched to 2xAI Sol Blue LED lights and now the fans never run and the tank stays 78-79 year round.

 

Thanks for the info dessert rat. If anyone would know cooling it would be someone from Phoenix. About what temp does your house get up to in the summer? I'm planning on keeping it 75-77 here this summer. By the way, I did my time in Phoenix. Both days it was over 120 I was working outside all day. I don't miss the heat, but the winters are great.

 

It stays 75-77 when we are home and up to 80-82 when we are away.
I had a detailed build on my canopy and fans on AZReefs but the site shut down about a week ago so can't access it anymore.

 

That's great news AZ. I may just start with cutting a couple holes in the back and see how it goes.

 

Here is one of my big concerns with cooling. The cabinet where the sump goes is nearly closed in. That hole on the back is only 9"*5". Its there more for electrical access, ect. than for cooling. My first and preferred plan is to put fans on the sump. The more I think about this I'd still like to at least vent the sump area. My concern is if I cut holes, I'm not sure how that would affect the structure. Would I be best off just dealing with cooling by doing whatever mods are necessary to the canopy our should I go ahead and add ventilation to the cabinet?

 

Personally, I'd be concerned with compromising the structural integrity of the cabinet. I also doubt you'd gain much in the cooling department without a chiller. The bulk of excess heat will come from your lighting; venting that away from the water will provide the easiest and most efficient means of controlling your tank temp.

 

I was told from several people and doing research that you have the fans blowing inside and none blowing out. The canopy I have already had groove vent openings on each side of top of canopy which lets the hot air blow out. If you put your hand over the vent and first turn on the fans you can feel the hot air blow out. When I clean the bottom of canopy glass from salt creep with lights on the fans keep the glass cool to the touch.

The fans I posted are not powerful like a house fan but can move some air considering their size. All you need to do is do a 3" circle for each fan and the grills on bottom/top will hold everything in place. This way it protects your fingers...LoL

 

I'll take that advice Mr Bill. I'll just plan on handling the cooling from the canopy. Thanks.

 

Thanks for the input Oryo. I have sufficient confidence now that I can cool from the canopy so I'll get on with leveling the cabinet and putting it together. Thanks all for all the great advice.