computer fans

[droid_ca]

How quiet are computer fans and how much air can they move as I was thinking of ducting 2-into-1 and using them for circulating air in a tiny house but don't want to listen to a loud noise whining all night. and are they reversible so I can change the direction that the airflow's in

[zipz71]

There is some information here

http://www.circuittest.com/Media/Data/CTCAT-27.pdf

I don't know of any computer fans that are reversible.

[Shadow Catcher]

I used Antec three speed case fans and they say 100 CFM on high which I doubt. Our experience is we run them on medium to low and they are very quiet and quite sufficient. I wired them with a DPDT switch so that one or both can be run. The frame with the fans can be turned upside down to blow out or you could mount one or more fans blowing up and one or more blowing down. We have not felt the need to turn ours over, works great.

[Lgboro]

Google quiet computer fans, there are a couple of companies that specialize in quiet computers and sell most parts. I built mine into a regular non powered RV vent and couldn't be happier. I have 6 80mm fans that blow out and 2 larger fans that blow in and still had room to build in some custom led lights. I have the fans wired in pairs to a toggle switch so I only have to run the ones I need and also have a dimmer switch ahead of toggles so I can run at any speed. This system allows me to conserve battery is I need to so I am not completely without lights or fans.

[droid_ca]

I like the idea of a dimmer switch before the toggle switch that is a good idea...I might need to borrow that one. I googled reversible fans and it basically lt said that I could set up one fan to blow air and one fan to suck air I guess I'll just order a couple and try them out and see what happens cause I'd like to place 2 in a heat vent and the have the adapter that goes into a smaller pipe and have that go down towards the bottom of the trailer and go into another adapter so I could have 2 more fans there and if I can get them to reverse then I'd have to install a 3way switch one at both locations with a dimmer at both locations so I can control the air flow but I'm thinking that if I have 4 fans moving roughly 400cfm then it might be noticeable...who knows might have to do more then one vent setup like that and then really get the air moving ..Thanks for the information

[Shadow Catcher]

A dimmer switch may not work (they work with AC not DC), and if you use a variable resistor you waste power. The three speed Antec fans use less power on medium and low than on high, a variable resistor wastes the power as heat.

[eamarquardt]

These should work.

Gus

http://www.ebay.com/itm/CPU-Cooling-Fan ... 2ec0fb6d54

http://www.ebay.com/itm/STW-6051-5-25-P ... 4abca50586

http://www.ebay.com/itm/3-Channel-PC-Fa ... 3cc99a714a

http://www.ebay.com/itm/4-Channel-Fan-S ... 4ab974c9e8

http://www.dealaboo.com/usa/Sunbeam-PL- ... 86985.html

[droid_ca]

Thanks Gus good ol ebay I'll check them out

[working on it]

Of course, it makes a difference in what one considers quiet or noisy http://www.makeitlouder.com/Decibel%20Level%20Chart.txt. I am going to use two high static pressure performance Corsair SP-120 fans set up to blow out thru screened butterfly vents (2) , full-time, when my trailer is stored (in my unsealed garage/shed that has lots of dust and insects year round). I want to create negative pressure in the trailer to keep out dust, insects, and mold by doing so. The fans will be hinged to the wall and can be swung in and out of position, used in tandem, at full or half speed (an in-line adapter with resistor can be plugged in to go 1/2 speed). When camping, the fans will not be needed, as a Honeywell fan http://www.homedepot.com/h_d1/N-5yc1v/R-202182997/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=honeywell+fans&storeId=10051will be used and the computer fans will be off and swung away from the opened vents, and/or with opened windows. I am also considering this fan http://www.skycraftsurplus.com/12vdcfan235cfmcomairrotron.aspx as a 12vdc alternative (and I don't mind a few decbels, now and then). As further info, here are some charts I found that compare various fans and cfm airflow, that I basd my choice of the Corsair fans mentioned above:

Fan Noise at 12V.jpg (118.74 KiB) Viewed 2475 times

12V PQ Curves.jpg (114.24 KiB) Viewed 2475 times

7V PQ Curves.jpg (113.6 KiB) Viewed 2475 times

[Lgboro]

I used pulse width modulated switches for the variable switch to control both led lights and my computer fan set up. They were a little pricy but could not perform better. On a 6 week cross country trip just completed my 55 ah battery never got below 70% running lights as needed, fans, and radio all night to off set noise when over night at truck stops or other parking lots. Never stayed where electric was available so my only means of power was an 80 watt solar panel and I had more power than I used on a daily basis.

[droid_ca]

That is some great information I just was thinking I'd need fans for air circulation draw the hot air from up high and move it down low and possibly on the opiste side of the trailer so I'd have it at a consistent temprature since it will be going in a Tiny House