reversible cooling fan

spdjnky · 11/16/2017, 09:11 AM

Need help finding fan and parts to install a fan in my new sump cabinet build.
I have the vent to the other room in and want a fan that I can reverse the direction depending on the temp of my house.

slief · 11/16/2017, 09:44 AM

I don’t think you will find any small fan that is reversible since most fan blades are designed to be directional. Your best bet will be to use two fans. One at the vent blowing in and one at the duct hole blowing in. Then use your controller to trigger one fan or the other depending on whether you want to pull air from the room or push air to the room.

spdjnky · 11/16/2017, 10:35 AM

Thx Didn't think of that. Don't have a controller
here are some pics
https://photos.app.goo.gl/8OT2DkUF6qK23GUM2
Hope u can see that the aquarium is in the wall and the living room where the vent is has a pellet stove and then air in the summer so right now while I am wiring everything and setting it all up I figured it would be best so it's there if I want it.

MurphyLong · 11/16/2017, 10:56 AM

https://www.acinfinity.com/quiet-cabinet-fans/

mcgyvr · 11/16/2017, 11:21 AM

Bi - directional may likely not be needed.. (not enough details in the pics,etc..)
But to exhaust air you also have to bring it in from somewhere or you pressurize the room which ain't gonna happen with a circulation fan..

All you need is one direction circulation to mix the air.. It more than likely does not need to be pushed then pulled depending on the season,etc.. as pushing it out is going to pull it in anyways under the door crack,etc....

The "best" direction for the fan would be to push the least humid air into the area of higher humidity to keep the bearings of the fan,etc.. from being exposed to "more humid" air.. But direction really shouldn't matter after that..

d0ughb0y · 11/16/2017, 11:30 AM

fans run on dc. did you try reversing the polarity to see if fan spins the opposite direction?

mcgyvr · 11/16/2017, 11:36 AM

Quote:

Originally Posted by d0ughb0y

fans run on dc. did you try reversing the polarity to see if fan spins the opposite direction?

Depending on the specific fan that may damage its internal hall effect sensors but I'd expect reverse polarity protection if it would.. never know though..
The props are certainly designed for one one direction and I'd expect a large loss of performance even if you did get them to spin backwards..

I still doubt reversing is needed at all.. The warm air from the fireplace room is going to be pulled into the back room even when blowing air out of it..

d0ughb0y · 11/16/2017, 11:40 AM

if you do not need the tach reading and only need on or off, then it may work.

ceiling fans have switch to make them spin backwards, so there are situations where reverse spin is appropriate.

mcgyvr · 11/16/2017, 11:49 AM

Quote:

Originally Posted by d0ughb0y

if you do not need the tach reading and only need on or off, then it may work.

ceiling fans have switch to make them spin backwards, so there are situations where reverse spin is appropriate.

There are certainly fans (motors/electronics) that can go both directions (still may be a difference in performance as far as fan blade geometry is concerned though but ceiling fan pitches are designed to mitigate that because they are intended to work in both directions) ..

And then there are those than cannot or should not.
My comment was mostly about your typical computer type fans which are not the same type of motors or technology that is used in ceiling fans..

But again.. its likely a misunderstanding of how it all works....in this application/situation.. to push air out.. air must go in too..

oreo57 · 11/16/2017, 11:59 AM

Quote:

Originally Posted by mcgyvr

There are certainly fans (motors/electronics) that can go both directions
And then there are those than cannot or should not.
My comment was mostly about your typical computer type fans which are not the same type of motors or technology that is used in ceiling fans..

Quote:

I've worked with DC fans since they started. The standard Brushless DC fan will not work when the polarity is reversed. You may or may not kill it based on the manufacturer. I am not sure if you can buy a DC fan which uses a brush type DC motor, but that motor will reverse direction when polarity is reversed. You will also have the problem of finding a fanblade which blows effectively when reversed. One possibility is to buy two Brushless DC fans and mount them back to back. Then use a switch to turn on one and or the other. A single pole double throw (SPDT) switch will do. The voltage is not critical, but should not be very much higher than allowed by the fan "running" specs. ( A 12 VDC fan will run at 15VDC). Never violate the absolute max specs.

Best fit..
Example:
https://products.sanyodenki.com/en/c...st.php?CNo=269

spdjnky · 11/16/2017, 06:46 PM

wow thx guys now I'm really confused lol Here's a few more pic's mcgyvr. What u see is our small room that we made a laundry room that's also not finished yet. But it is small and with the bifold door closed and my wife has the stove cranked(dam sometimes I come in and it's like 78) up it's cooler. When I had the old sump and the cabinet closed this past summer I had to leave the doors off when it was hot and no air on in the main room. It's only the 2 of us so doing laundry does not really come into play. But small room the humidity was up there, even tried a small air conditioner in the window pain in the a--- didn't work could not regulate. The old doors in the picture will go back on just have not got to that part yet but they are louver doors so they get some air. I just use magnets
to hold works great easy to take out of the way when u need to get in there.

https://photos.app.goo.gl/teNSZDf0Kc6a83rZ2
https://photos.app.goo.gl/af2w5OjvabmDQB0R2

spdjnky · 11/16/2017, 07:01 PM

While I rebuilt the whole underside I didn't want to miss anything and I still new to this hobby I figured that the better I could make the temp in the cabinet stay consistent the better.
I just wanted to be able to control the flow thru the cabinet and I figured that in the summer when it got Hot it might be better to draw air from the front. Bigger room and the air conditioner is right there. But with the room size in the back maybe get a IceCap 4” Smart Fan from BRS and have it exhaust to the from room.

spdjnky · 11/16/2017, 07:18 PM

On second thought thx Murthylong I think one of them a the best and I haven't looked much yet but u can (Fans are set to exhaust air out the frame but this can be reversed to intake air using a screw driver. Includes all necessary hardware to easily mount the unit onto a cabinet and power it through an USB port or standard wall outlet. If I could DIY them right and hook them tru a thermostat maybe. But then again is it worth the extra time and work.

11/16/2017, 09:11 AM	#1
spdjnky Registered Member Join Date: Dec 2014 Location: Schenectady,NY Posts: 165	reversible cooling fan Need help finding fan and parts to install a fan in my new sump cabinet build. I have the vent to the other room in and want a fan that I can reverse the direction depending on the temp of my house.

11/16/2017, 09:44 AM	#2
slief RC Sponsor Join Date: Sep 2009 Posts: 14,173	I don’t think you will find any small fan that is reversible since most fan blades are designed to be directional. Your best bet will be to use two fans. One at the vent blowing in and one at the duct hole blowing in. Then use your controller to trigger one fan or the other depending on whether you want to pull air from the room or push air to the room. __________________ Director Customer Support Royal Exclusiv USA For All Royal Exclusiv & Bubble King questions please refer to our Sponsor forum: http://www.reefcentral.com/forums/fo...play.php?f=745 Current Tank Info: 480G display mixed reef, 90G sump, 90G refugium, 60G display refugium. Check out my build thread: http://www.reefcentral.com/forums/showthread.php?t=1783476

11/16/2017, 10:56 AM	#4
MurphyLong HMFIC Join Date: Apr 2017 Location: Eastern NC Posts: 331	https://www.acinfinity.com/quiet-cabinet-fans/ __________________ Preparing to get my hands wet... again.

11/16/2017, 11:21 AM	#5
mcgyvr Registered Member Join Date: Sep 2003 Location: North Carolina Posts: 20,050	Bi - directional may likely not be needed.. (not enough details in the pics,etc..) But to exhaust air you also have to bring it in from somewhere or you pressurize the room which ain't gonna happen with a circulation fan.. All you need is one direction circulation to mix the air.. It more than likely does not need to be pushed then pulled depending on the season,etc.. as pushing it out is going to pull it in anyways under the door crack,etc.... The "best" direction for the fan would be to push the least humid air into the area of higher humidity to keep the bearings of the fan,etc.. from being exposed to "more humid" air.. But direction really shouldn't matter after that.. __________________ Who me?

11/16/2017, 07:01 PM	#12
spdjnky Registered Member Join Date: Dec 2014 Location: Schenectady,NY Posts: 165	While I rebuilt the whole underside I didn't want to miss anything and I still new to this hobby I figured that the better I could make the temp in the cabinet stay consistent the better. I just wanted to be able to control the flow thru the cabinet and I figured that in the summer when it got Hot it might be better to draw air from the front. Bigger room and the air conditioner is right there. But with the room size in the back maybe get a IceCap 4” Smart Fan from BRS and have it exhaust to the from room. Last edited by spdjnky; 11/16/2017 at 07:08 PM. Reason: change

11/16/2017, 10:35 AM	#3
spdjnky Registered Member Join Date: Dec 2014 Location: Schenectady,NY Posts: 165	Thx Didn't think of that. Don't have a controller here are some pics https://photos.app.goo.gl/8OT2DkUF6qK23GUM2 Hope u can see that the aquarium is in the wall and the living room where the vent is has a pellet stove and then air in the summer so right now while I am wiring everything and setting it all up I figured it would be best so it's there if I want it.

11/16/2017, 11:30 AM	#6
d0ughb0y Registered Member Join Date: Mar 2008 Location: sf bay area Posts: 5,165	fans run on dc. did you try reversing the polarity to see if fan spins the opposite direction?

11/16/2017, 11:40 AM	#8
d0ughb0y Registered Member Join Date: Mar 2008 Location: sf bay area Posts: 5,165	if you do not need the tach reading and only need on or off, then it may work. ceiling fans have switch to make them spin backwards, so there are situations where reverse spin is appropriate.

11/16/2017, 06:46 PM	#11
spdjnky Registered Member Join Date: Dec 2014 Location: Schenectady,NY Posts: 165	wow thx guys now I'm really confused lol Here's a few more pic's mcgyvr. What u see is our small room that we made a laundry room that's also not finished yet. But it is small and with the bifold door closed and my wife has the stove cranked(dam sometimes I come in and it's like 78) up it's cooler. When I had the old sump and the cabinet closed this past summer I had to leave the doors off when it was hot and no air on in the main room. It's only the 2 of us so doing laundry does not really come into play. But small room the humidity was up there, even tried a small air conditioner in the window pain in the a--- didn't work could not regulate. The old doors in the picture will go back on just have not got to that part yet but they are louver doors so they get some air. I just use magnets to hold works great easy to take out of the way when u need to get in there. https://photos.app.goo.gl/teNSZDf0Kc6a83rZ2 https://photos.app.goo.gl/af2w5OjvabmDQB0R2

11/16/2017, 07:18 PM	#13
spdjnky Registered Member Join Date: Dec 2014 Location: Schenectady,NY Posts: 165	On second thought thx Murthylong I think one of them a the best and I haven't looked much yet but u can (Fans are set to exhaust air out the frame but this can be reversed to intake air using a screw driver. Includes all necessary hardware to easily mount the unit onto a cabinet and power it through an USB port or standard wall outlet. If I could DIY them right and hook them tru a thermostat maybe. But then again is it worth the extra time and work.