120 VAC Cooling Fan for Generator

wagwar · August 07, 2012, 08:55:06 AM

On a recent thread regarding bus wiring, ATS' and the proper type of wire to use in a coach, mention was made by Sean of a 120VAC cooling fan could be used more effectively than low voltage DC fans for cooling the generator head. My genset has its radiator for cooling, but I wanted to supplement that with additional cooling on the gen. head.

That reminded me that I had exactly that little project on my list. However, a search of Grainger and other vendors has not revealed a suitable direct drive squirrel-cage fan that fits the bill. All of the ones I find are less than 1HP, but still have a 10 - 12 Amp rating. That seems rather high for what I am trying to accomplish and I'm not sure I want to sacrifice that many amps on a single 30A leg:

1. To put an immediate stabilizing load on the generator.
2. To pull air into my inverter bay and blow air onto the generator head for cooling.

Can anyone suggest specs such as HP rating, CFM, Amp rating, etc. for a suitable fan for this purpose? Or maybe you have solved this one before and can recommend a make and model.

Tenor · August 07, 2012, 11:30:05 AM

I just got a used one from a furnace installer. This may seem obvious, but you do want one with the interior/integral motor. Not the belt driven external motor model. Mine serves 2 purposes. It draws air over the generator from one side, the other pulls air through the radiator. FWIW!

Glenn

gus · August 07, 2012, 01:09:53 PM

I got a small 120v, cheap, used squirrel cage blower on theBay that was around 300 cfm as I remember. I use it the same way you intend to and it does a great job. It draws less than one amp.

CFM is the key, not HP - the more the better.

wagwar · August 07, 2012, 05:00:50 PM

Thanks!

How many amps do your fans pull?

TomC · August 07, 2012, 11:31:16 PM

My 10kw 4 cylinder Kubota is in a very tight engine compartment next to the front seat like a front engine on my transit. The radiator is remote mounted. I use an 8" 250cfm inline bathroom ventilator (to withstand moisture). It blows directly on the alternator head intake and the exhaust out of the compartment is at the other end to take the heat with it. With the ducting capability, you can mount the blower anywhere and just run a 8", or like I did and split the 8" into two 6" ducts. Works well, TomC

desi arnaz · August 08, 2012, 02:38:20 AM

I use two $18 radiator fans from eBay attached to the screen door of the old a.c cage.works great and powered by the 12 volt battery charge port on the generator.

luvrbus · August 08, 2012, 04:40:04 PM

Inline duct fans work good you can purchased a 500 cfm 3/4 amp draw for less than 30 bucks

wagwar · August 08, 2012, 05:31:08 PM

50 cfm? Less than an Amp? Less than 30 bucks?

That sounds perfect!!!

A quick look at Grainger, ebay, amazon and google tho' revealed a cost more like $100. Still not bad at all.

Do you have another source to suggest?

Quote from: luvrbus on August 08, 2012, 04:40:04 PM
Inline duct fans work good you can purchased a 500 cfm 3/4 amp draw for less than 30 bucks

luvrbus · August 08, 2012, 05:59:50 PM

I bought from Rockler the regular price was 35 or 36 bucks I paid 25.99 on sale and their sales are like everyday prices most places lol

good luck