Fans blowing in or out
- Thread starter lm
- Start date
T
thomas712
Guest
One on each side of the canopy, one blowing in and accross to the one blowing out.
Thomas
Thomas
mikegronholz
Member
All in, the air will find a way out (or your canopy will levitate) !!! I use peg board in the backs of my canopies. Reduses the amount of light lost, and as I said, the air will find a way out !!!
Doing the push/pull thing, you create a draft of a single stream of cool in/cool out.
Doing the push/pull thing, you create a draft of a single stream of cool in/cool out.
saltynewbie
Member
another bit of info... the salty air you pull out tends to ruin the fans pretty quick... i would recommend (through experience) that you make the fans blow dry air in.. HTH 
broomer5
Active Member
Lots of good opinions on fans ~ whatever works for you is best.
Personally - I've got two Icecap variable speed 4" fans mounted in the top of canopy.
Both mounted blowing out and up.
As mentioned - heat in the canopy will rise.
My aim was to remove the hot/warm air ~ get it out away from the water surface, and allow cooler ambient room temperature air to be pulled in at the lower back of the hood.
My canopy measures 48"L x 19"W x 15"H
That's roughly about 13,680 cubic inches of air - give or take.
Approximately 8 cubic feet of air.
The Icecap fans each run at a speed that is determined by the air temperature at the sensor.
According to Icecap specifications ~ they each run anywhere from 50 to 90 cubic feet per minute with the guards in place.
I've not read where these airflows are "actual" ACFM or are listed at standard conditions "SCFM".
With just the 440watts of VHO powered up - they both run at lower speed.
When I have the 440watts VHO and the 500 watts of MH running - both fans are going full throttle.
If I assume the specs are right - the 90 CFM x 2 = 180 CFM.
Assuming once again ~ that would lead me to believe that the air is being exhausted at a rate of 20+/- times the total canopy volume per minute.
I've yet to take any measurements - because I don't feel the need.
The tankwater temperature has not risen over 82 degrees in the last 5 months.
Room temperature air is normally around 70-75 F.
I'm a big fan of having both fans mounted so that they both blow air out of the enclosure - up and away from the water.
It works for me ~ so I'm pleased with the set up.
My 2 cents
Personally - I've got two Icecap variable speed 4" fans mounted in the top of canopy.
Both mounted blowing out and up.
As mentioned - heat in the canopy will rise.
My aim was to remove the hot/warm air ~ get it out away from the water surface, and allow cooler ambient room temperature air to be pulled in at the lower back of the hood.
My canopy measures 48"L x 19"W x 15"H
That's roughly about 13,680 cubic inches of air - give or take.
Approximately 8 cubic feet of air.
The Icecap fans each run at a speed that is determined by the air temperature at the sensor.
According to Icecap specifications ~ they each run anywhere from 50 to 90 cubic feet per minute with the guards in place.
I've not read where these airflows are "actual" ACFM or are listed at standard conditions "SCFM".
With just the 440watts of VHO powered up - they both run at lower speed.
When I have the 440watts VHO and the 500 watts of MH running - both fans are going full throttle.
If I assume the specs are right - the 90 CFM x 2 = 180 CFM.
Assuming once again ~ that would lead me to believe that the air is being exhausted at a rate of 20+/- times the total canopy volume per minute.
I've yet to take any measurements - because I don't feel the need.
The tankwater temperature has not risen over 82 degrees in the last 5 months.
Room temperature air is normally around 70-75 F.
I'm a big fan of having both fans mounted so that they both blow air out of the enclosure - up and away from the water.
It works for me ~ so I'm pleased with the set up.
My 2 cents
chainsaw5vent
Member
hey broomer! cool hood setup. i've been looking at revamping my old tired, broken down hood and i've never seen anyone w/ the fans installed on the top. they've always been mounted on the sides or the rear.
mikegronholz
Member
I have 6 4.5" fans on mine. 1 on each side and 4 on top.
tyr-sog
Member
JBJ's have 2 fans blowing out if this helps at all. Maybe they researched it a bit .
In my own opinion I would think out just because I would think blowing in would just shuffle the hot ait around more so before blowing it out. Blowing out would create a constint airflow across the whole case.
In my own opinion I would think out just because I would think blowing in would just shuffle the hot ait around more so before blowing it out. Blowing out would create a constint airflow across the whole case.
cyslyde
Member
I have Two 120mm blowing up out of the top, and two on each side, Left and right, 90mm blowing cool air in, I all these are hooked to an old 250watt computer power supply, using a fan buss to select how much power to send to them... used to keep my cpu pretty cool, figured it'd do ok on the tank. I decided not to have any on the back of the tank because after dooing tests i found that quite a bit of hot air collected back there.
just how i did it.
just how i did it.
broomer5
Active Member
cmpowell
Thanks - the canopy set me back some bucks.
All items purchased online - and built the unit in the garage - summer project.
Equipment list:
(1) PFO MH 250Watt HQI Dual Ballast
(2) Ushio 10K 250 MH lamps
(2) Mogul Sockets w/reflectors
(1) PFO Extension cord
(4) URI 46.5" 100 watt VHO lamps
(1) PFO 4 lamp VHO ballast / Retro with 3-piece end caps
(4) Timers
(2) Icecap 4" fans
Wood
Hardware
Paint/Fishish
It's expensive no matter how you do it
Thanks - the canopy set me back some bucks.
All items purchased online - and built the unit in the garage - summer project.
Equipment list:
(1) PFO MH 250Watt HQI Dual Ballast
(2) Ushio 10K 250 MH lamps
(2) Mogul Sockets w/reflectors
(1) PFO Extension cord
(4) URI 46.5" 100 watt VHO lamps
(1) PFO 4 lamp VHO ballast / Retro with 3-piece end caps
(4) Timers
(2) Icecap 4" fans
Wood
Hardware
Paint/Fishish
It's expensive no matter how you do it
pyro383
Member
mine blows in with a semi open back. Without the 115cfm fan air temp inside hood is 97, when fan goes on air temp is 70. Water without fan is 86 when on is 80. I evaporate 2g a day. I have read that you should pull air in as long as its not over 90. You want fresh air coming in due to the fact is pushes air out the canopy, blowing out tries to gather the air from a large area to a smaller area and is less effective. Also for those that have 1 in 1 out, this is very ineffective if they are level to each other on opposite sides because you create a lane of air and does not grab air around it. So put both going in or remove the one blowing out and just put a grill there as it will suck air in also.