Canopy cooler than ambient?

[Saintnovakai]

Hey fellow reefers. I have a problem. Also contacted AZdesertrat but still waiting on a reply. Figure id pick the team's brain meanwhile.

I live in the Caribbean and in the summer with two 4 inch computer fans over my open top reef tank and a 16 inch fan usually blowing in the room, my Temps attempt daily to climb past 84. My alarm goes off at 83 which tells me it's time to add my bottles of ice to bring it back down to 81. My tank is used to the swing and have seen no ill effects but i hate feeling like my reef teeters on me catching a temp rise on time.

The room itself tends to be warm but cooler than the tank. Do you suggest building a canopy using your two fans in and vents above design? Or am I better served just trying to throw fans at the open tank?

I like the clean look of a canopy but always feared heat. Wondering if the canopy would allow more of a controlled environment and give positive results. Any thoughts?

Wanted to include a T5 hybrid but kinda scared. Lol. A chiller isn't an option unfortunately. Cant afford one as importing it alone would be over its cost.

 

[Brad Miller]

Possibly build an “open top” canopy that looks nice and mount fans inside it that would blow over the tank surface water on a temp controller

 

[Saintnovakai]

Possibly build an “open top” canopy that looks nice and mount fans inside it that would blow over the tank surface water on a temp controller

Cooling is my major goal. Canopy or no canopy is fine by me. I need a way to keep my Temps down so I'm wondering if a canopy would work better than open top.

 

[Brad Miller]

I was thinking to build a canopy above your tank at your light level to be an open top for dissipating heat from the lights while mounting fans inside the canopy and blow over the water surface......
open top, fans hidden from view.

If I understand you correctly, a canopy with fans blowing in and vented out wouldn’t have the same evaporative cooling effect since they would essentially be bringing in room air and mixing the heated air from the lights across the water before it exited the vents.

Best to move 100% room air over as much of the water surface as possible by blowing directly on the water for the best cooling effect.

 

[Saintnovakai]

I had that same suspicion but what I realized is that more often than not, the room is cooler than the tank. It's as if the water won't let the heat go even an hour after the room cools off.

I did read an article however that stated that cooling fans on an open reef has the detriment of trying to cool the entire room vs just the water. Presumably, with an open top or canopy, it's the same air being moved from inside out no matter the design. I was just banking in the fact that the tank may not have all the room air being sucked into the water but a concentrated amount. That's where I'm stuck. I've never in a canopy so I need the experience of those who have before I commit to a build.

My lights will move lower if I run a canopy, no biggy.

 

[JasonK84]

Central A/C

My house is 72 year round.

 

[motortrendz]

Could you run a chiller? I have a canopy and had to put holes in the top to try and vent the hot air from the leds. That helped a little. But even with my house at 74 the tank gets up to 79 (that's where my chiller comes on just to stop it from getting hotter) it's way undersized but it's enough to stop the temp climb in the middle of the day

 

[Brad Miller]

I had that same suspicion but what I realized is that more often than not, the room is cooler than the tank. It's as if the water won't let the heat go even an hour after the room cools off.

I did read an article however that stated that cooling fans on an open reef has the detriment of trying to cool the entire room vs just the water. Presumably, with an open top or canopy, it's the same air being moved from inside out no matter the design. I was just banking in the fact that the tank may not have all the room air being sucked into the water but a concentrated amount. That's where I'm stuck. I've never in a canopy so I need the experience of those who have before I commit to a build.

My lights will move lower if I run a canopy, no biggy.

I’ve been in the industrial HVAC trade for over 35 years and deal with “evaporative cooling on an almost daily basis.
There is no “detriment” to blowing air across the water surface, it’s the only way to cool off the tank water...same as what we do with “cooling towers”

 

[Saintnovakai]

I’ve been in the industrial HVAC trade for over 35 years and deal with “evaporative cooling on an almost daily basis.
There is no “detriment” to blowing air across the water surface, it’s the only way to cool off the tank water...same as what we do with “cooling towers”

So with that knowledge and being unable to run a chiller, how would you do it? Most times the room is just a bit cooler than the tank but the tank seems to just suck up the warm air and compound the heat issue and doesn't readily let it go. Either way I'm blowing the room air over the tank. Question is, would a confined environment (canopy) be more effective at maintaining and lowering temps vs exposing the tank to the whole room?

 

[Brad Miller]

Evaporative Cooling = The cooling effect produced by changing water from a liquid to a vapor.

BTU/HR = a specific measurable amount of heat being added to or given up by your tank.

This is influenced by all of the by following;

Tank water volume
Amount of top surface area of the tank water
Tank temp
Room temp
Room humidity
Salinity of tank water
Heat given off by your Lighting
Type and amount of air flow over the water surface

Put simply, we can calculate the exact length of time it would take to cool down or raise the temp of your tank water under any given arrangement of all of the above parameters.

The less humid it is in the room the more evaporative cooling effect you will have by moving room air over the water surface.

Some will only place a small clip on fan hidden over their sump and that may do the trick if it’s a small tank volume, but many will need to blow room air over the tank water top surface because the more water surface the fan air can contact the more cooling effect you will get.

Some will build a canopy to put the fans in for that clean look.

No matter how you may do it, the best results will be if you allow room air only to be blown across the water surface. You’d be surprised how little air flow is necessary to achieve good results using a temp controller to turn on and off the fan.

With no fan in use, when you notice the tank water getting warmer even though the room air is less than the tank temperature, this is telling you that you are adding more heat to the tank by your lighting, power heads and pump than the cooler room air can cool the tank water off by means of attracting the tank water heat through the aquarium glass. (Warm will flow to cold)

It’s a balance of BTU/HR of heat added to the tank versus BTU/HR of any cooling of the tank water.

Throw a fan into the equation and you now can cool the tank with “evaporative cooling” just like a chiller would.

Of course you will be evaporating the tank water more, this is a given.

You may need a lot more air flow than computer fans.

I hope this answers your initial question.

 

[Saintnovakai]

Evaporative Cooling = The cooling effect produced by changing water from a liquid to a vapor.

BTU/HR = a specific measurable amount of heat being added to or given up by your tank.

This is influenced by all of the by following;

Tank water volume
Amount of top surface area of the tank water
Tank temp
Room temp
Room humidity
Salinity of tank water
Heat given off by your Lighting
Type and amount of air flow over the water surface

Put simply, we can calculate the exact length of time it would take to cool down or raise the temp of your tank water under any given arrangement of all of the above parameters.

The less humid it is in the room the more evaporative cooling effect you will have by moving room air over the water surface.

Some will only place a small clip on fan hidden over their sump and that may do the trick if it’s a small tank volume, but many will need to blow room air over the tank water top surface because the more water surface the fan air can contact the more cooling effect you will get.

Some will build a canopy to put the fans in for that clean look.

No matter how you may do it, the best results will be if you allow room air only to be blown across the water surface. You’d be surprised how little air flow is necessary to achieve good results using a temp controller to turn on and off the fan.

With no fan in use, when you notice the tank water getting warmer even though the room air is less than the tank temperature, this is telling you that you are adding more heat to the tank by your lighting, power heads and pump than the cooler room air can cool the tank water off by means of attracting the tank water heat through the aquarium glass. (Warm will flow to cold)

It’s a balance of BTU/HR of heat added to the tank versus BTU/HR of any cooling of the tank water.

Throw a fan into the equation and you now can cool the tank with “evaporative cooling” just like a chiller would.

Of course you will be evaporating the tank water more, this is a given.

You may need a lot more air flow than computer fans.

I hope this answers your initial question.

Ok so to test the theory of my computer fans being underpowered, although when I step in front of the tank I can feel the strong breeze, I've ordered one of the 6 inch fans like from home Depot that some people swear by. I'll see how that goes and report back. Thanks guys.

 

[Brad Miller]

To compliment your test....
See if you can measure the amount of top off water being added to the tank in a 24 hour period as it is now, then do the same with more air flow and see what the difference is in the amount of evaporation taking place.