Canopy fans. Which way should they blow?

JohnnyM2 · 01/30/2007, 04:21 PM

It seems to me that fans in my canopy serve three purposes, to remove heat from the lights to protect the lights, to remove heat from the canopy to avoid transferring it to the tank and to remove humidity. I have a 48" coralife retrofit in the canopy with metal halides and actinics and have installed a fan at one end of the retrofit light, blowing across the length of the reflector. I did not cut a hole in the canopy so this fan draws air from the long rectangular opening across the back of the canopy. I have another fan but don't know where to put it. Here are my choices:
1. cut a hole at the other end of the canopy and set the fan to blow inward where its flow will collide with the flow from the first fan. i.e. blow cool air in
2. cut the same hole but have it blow out. i.e. draw warm air out.
3. mount the fan in the long rectangular opening blowing in or out.
Does anyone have any advice or even another alternative. Not really anxious to cut holes in the canopy.

AZDesertRat · 01/30/2007, 04:35 PM

I prefer one fan in each end both blowing in across the length of the tank and lights. I have equal sized opening on the top of the canopy directly over my reflectors so heat escapes but light does not. By having the holes in top you also take advantage of convection. My fans are 4" (120mm) Vantec Stealths powered by DC adjustable voltage power supplies so I can vary the fan speed according to the seasons and heat load. Power supplies can be found at Radio Shack, WalMart, Frys Electronics or Harbor Freight Tools among others and are only about $4 each in some cases.

elzool · 01/30/2007, 05:10 PM

I just installed fans in my canopy in preparation for a T5 setup I'll be putting in shortly. I put in 4 80mm fans and 2 60mm fans.

One on each side blowing into the canopy (60mm).
Four in the back blowing into the canopy.

As the back of the canopy is open, it doesn't matter if you have fans blowing out, the canopy isn't airtight and air will still escape.

The power supply AZDesertRat mentioned is what I use. It is wired to a Y-Adapter. That Y Adapter has a Y-adapter on each end going from two to four outlets, then another two more Y Adapters are plugged in giving me 6 outlets all together. As long as I don't exceed the capacity of the power adapter I'm good.

aqua_carmen · 01/30/2007, 05:15 PM

2 fans on top shooting the air out. Put holes for cords and such in the back and that will suck in the air for you there is no need for air shooting in. That's how I have my canopy setup which I just installed 1 month ago. It's also better to have the fans on top rather than on the sides because heat rises and you will not see the holes in ur canopy unless your really tall.

I am running 3 - 175 watt Metal halides and a PC.

AZDesertRat · 01/30/2007, 05:23 PM

Fans blowing out are usually short lived due to moist air being sucked into them. I have been down that road with previous tanks.

aqua_carmen · 01/30/2007, 05:34 PM

Oh I see, I'll change them down tonight. Thanks for that heads up AZ.

Im SpSing · 01/30/2007, 05:39 PM

I have had the same fan blowing out of my canopy for about a year.

RicGio · 01/30/2007, 05:45 PM

Had the same fan blowing out my canopy for 4 years, casing shows a bit of rust though.

JohnnyM2 · 01/30/2007, 09:00 PM

Thanks to all. This information was really helpful. I will look into the vantecs and will likely have all fans blow in. The updraft idea however is very good and I may do that if my wife will let me cut holes in the top of the canopy.

elzool · 01/30/2007, 10:16 PM

she play for the WNBA?

if not, she'll likely never notice

treejohnny · 01/31/2007, 11:02 AM

have a silly question for you all....do you have lids on your tanks....between lights and water of course

AZDesertRat · 01/31/2007, 11:06 AM

No. Glass covers get dirty with salt spray blocking light. They also trap heat inside and do not allow good oxygen transfer at the waters surface.

elzool · 01/31/2007, 11:11 AM

eggcrate lid

JohnnyM2 · 01/31/2007, 11:16 AM

I am going to put in egg crate to help keep the fishies in.

ErikS · 01/31/2007, 11:48 AM

Quote:

Fans blowing out are usually short lived due to moist air being sucked into them. I have been down that road with previous tanks

Preach on.............been there done that, got the t-shirt.

If they last 6 months blowing out that's a heck of a fan.

01/30/2007, 04:21 PM	#1
JohnnyM2 Registered Member Join Date: May 2006 Location: Tyler, TX Posts: 98	Canopy fans. Which way should they blow? It seems to me that fans in my canopy serve three purposes, to remove heat from the lights to protect the lights, to remove heat from the canopy to avoid transferring it to the tank and to remove humidity. I have a 48" coralife retrofit in the canopy with metal halides and actinics and have installed a fan at one end of the retrofit light, blowing across the length of the reflector. I did not cut a hole in the canopy so this fan draws air from the long rectangular opening across the back of the canopy. I have another fan but don't know where to put it. Here are my choices: 1. cut a hole at the other end of the canopy and set the fan to blow inward where its flow will collide with the flow from the first fan. i.e. blow cool air in 2. cut the same hole but have it blow out. i.e. draw warm air out. 3. mount the fan in the long rectangular opening blowing in or out. Does anyone have any advice or even another alternative. Not really anxious to cut holes in the canopy.

01/30/2007, 04:35 PM	#2
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	I prefer one fan in each end both blowing in across the length of the tank and lights. I have equal sized opening on the top of the canopy directly over my reflectors so heat escapes but light does not. By having the holes in top you also take advantage of convection. My fans are 4" (120mm) Vantec Stealths powered by DC adjustable voltage power supplies so I can vary the fan speed according to the seasons and heat load. Power supplies can be found at Radio Shack, WalMart, Frys Electronics or Harbor Freight Tools among others and are only about $4 each in some cases.

01/30/2007, 05:10 PM	#3
elzool Registered Member Join Date: Feb 2006 Location: Glendale, AZ. Posts: 1,005	I just installed fans in my canopy in preparation for a T5 setup I'll be putting in shortly. I put in 4 80mm fans and 2 60mm fans. One on each side blowing into the canopy (60mm). Four in the back blowing into the canopy. As the back of the canopy is open, it doesn't matter if you have fans blowing out, the canopy isn't airtight and air will still escape. The power supply AZDesertRat mentioned is what I use. It is wired to a Y-Adapter. That Y Adapter has a Y-adapter on each end going from two to four outlets, then another two more Y Adapters are plugged in giving me 6 outlets all together. As long as I don't exceed the capacity of the power adapter I'm good.

01/30/2007, 05:15 PM	#4
aqua_carmen Registered Member Join Date: Nov 2006 Location: Windsor, ON Canada Posts: 206	2 fans on top shooting the air out. Put holes for cords and such in the back and that will suck in the air for you there is no need for air shooting in. That's how I have my canopy setup which I just installed 1 month ago. It's also better to have the fans on top rather than on the sides because heat rises and you will not see the holes in ur canopy unless your really tall. I am running 3 - 175 watt Metal halides and a PC.

01/30/2007, 05:23 PM	#5
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	Fans blowing out are usually short lived due to moist air being sucked into them. I have been down that road with previous tanks.

01/30/2007, 05:34 PM	#6
aqua_carmen Registered Member Join Date: Nov 2006 Location: Windsor, ON Canada Posts: 206	Oh I see, I'll change them down tonight. Thanks for that heads up AZ.

01/30/2007, 05:39 PM	#7
Im SpSing Registered Member Join Date: Oct 2005 Location: New Orleans Posts: 177	I have had the same fan blowing out of my canopy for about a year.

01/30/2007, 05:45 PM	#8
RicGio Registered Member Join Date: Oct 2002 Location: NJ Posts: 658	Had the same fan blowing out my canopy for 4 years, casing shows a bit of rust though.

01/30/2007, 09:00 PM	#9
JohnnyM2 Registered Member Join Date: May 2006 Location: Tyler, TX Posts: 98	Thanks to all. This information was really helpful. I will look into the vantecs and will likely have all fans blow in. The updraft idea however is very good and I may do that if my wife will let me cut holes in the top of the canopy.

01/30/2007, 10:16 PM	#10
elzool Registered Member Join Date: Feb 2006 Location: Glendale, AZ. Posts: 1,005	she play for the WNBA? if not, she'll likely never notice

01/31/2007, 11:02 AM	#11
treejohnny Registered Member Join Date: Mar 2004 Location: Rockford, Illinois Posts: 335	have a silly question for you all....do you have lids on your tanks....between lights and water of course

01/31/2007, 11:06 AM	#12
AZDesertRat Moved On Join Date: Jan 2002 Location: NW Phoenix Posts: 16,621	No. Glass covers get dirty with salt spray blocking light. They also trap heat inside and do not allow good oxygen transfer at the waters surface.

01/31/2007, 11:11 AM	#13
elzool Registered Member Join Date: Feb 2006 Location: Glendale, AZ. Posts: 1,005	eggcrate lid

01/31/2007, 11:16 AM	#14
JohnnyM2 Registered Member Join Date: May 2006 Location: Tyler, TX Posts: 98	I am going to put in egg crate to help keep the fishies in.