holmes twin fan

billd6373

What watt panel would I need to use solar for summertime run of this fan I was looking at 40 watt

BB.

Re: holmes twin fan

Do you want to only run the fan when the sun is shining? Or do you want to run it in the evening/night.

If you want to run it at night, with a battery bank, then we need to know how many hours a night you want to run the fan and (roughly) where the installation will be (hours of sunlight).

For example, say 10 hours a night for the fan at 40 watts. And it will be 6+ months of the year with 4+ hours of sunlight (assume 52% system efficiency with a AC inverter to run the fan):

• 10 hours * 40 watts * 1/0.52 system eff * 1/4 hours of sun = 192 watts of solar panels minimum

Assuming 1 or 3 days of no-sun backup power and maximum of 50% discharge for a 12 volt battery bank:

• 40 watts * 10 hours * 1/0.85 inverter eff * 1/12 volt battery * 1 day of no sun * 1/0.50 max discharge = 78 AH @ 12 volt battery bank for 1 day of storage
• 40 watts * 1/0.85 inverter eff * 1/12 volt battery * 3 day of no sun * 1/0.50 max discharge =235 AH @ 12 volt battery bank for 3 days of storage

Anyway--some starting information.

-Bill

westbranch

Re: holmes twin fan

Walmart's page lists the fan at 61W
looks like they have misprinted the amps though... 47A??? .47A maybe

Slappy

Re: holmes twin fan

If this helps, just put a holmes twin fan on a kill-a-watt. It read (both motors running) on HI ---> .47 amps/ 54.3 watts....MED --> .36 amps/ 40.6 watts....LOW --> .32 amps/ 34.2 watts.

cant find the model # but it is the 9" twin, 6 blade, reversible, with manual thermostat.

billd6373

Re: holmes twin fan

thanks thats a lot of info but just want to run fan during summer heat wave probably will get battery not to waste ,but still dont know if 40 watt will do the trick

mike95490

Re: holmes twin fan

forget buying a battery and inverter and solar PV for a 60w fan, the fan will run for pennys a day, and you have a $100 battery, $300 PV and $50 charge controller and $40 mod square wave inverter , all that cash spent, will buy more electric from the grid, than the fan can use, it will die of old age before you can feed it $500 worth of grid power.

But if your power is intermittent, the fan running off a battery is priceless.

billd6373

Re: holmes twin fan

Im looking at a 40 watt panel just to run the fan cost 100 why should i pay if the sun will provide

mike95490

Re: holmes twin fan

billd6373 wrote: »

Im looking at a 40 watt panel just to run the fan cost 100 why should i pay if the sun will provide

The panel produces DC, and your fan needs AC. Also, panels seldom produce "nameplate" output, and your fan needs about 60W to run. (see the measurement someone made)

Only way to get AC from DC is with an inverter. Or you may want to consider a couple of 12VDC computer case fans.

Mike

BB.

Re: holmes twin fan

There are also low voltage DC ceiling fans

and they can draw less power.

Tony/Icarus has one in his place.

-Bill

Slappy

Re: holmes twin fan

Build6373, another route that you can take, is to use 2 radiator fans from an automobile, build window box, air filter, wire fans in series, use dash board dimmer switch, on/off switch from radio shack, fuse, with fans wired in series, they will pull very few amps. And they will be quiet, and push a heck of lot of air. that is what I did, and only used the AC of a total of 3 days last summer. (Just went to check the AMP on my set up, and it pulls 3.3 amps total on high). but mount the dimmer in front of one of the fans to keep it cool......

this way you can keep the set up simple, with out any conversion loss by using inverters. But the size panel will be your choice. You might not wont to do it this way, sense you got (or thinking to get) the holmes twin fan. well I just threw this out their any ways, just to give you an alternitive idea.

icarus

Re: holmes twin fan

Remember, a 40 watt panel (harbor freight or Northern tool) panels are not very good products. Any Pv will only produce ~80% name plate rating under nearly ideal conditions of full sun and low temps, so your 40 watt panel, best case will only produce ~ 30 watts on average, and that for ~ 4 hours a day.

Add in inverter loses, especially a cheap MSW inverter, wiring loses, and the net/net is likely to be closer to 20 watts out of the inverter! There are 12 vdc paddle fans out there, as well as a you can get for free or nearly free 12 vdc computer fans that will move a lot of air, drawing as little as ~ 5 watts, with no need for an inverter. You could wire them directly to a Pv panel with no controller or battery. The worst that will happen is you might burn them out due to low voltage, but at free, what's the risk.

Quite frankly, define what it is that you are really trying to accomplish, and then design a proper system to do that. Bottom line, like Mike suggests, you are probably not going to save money. As an interesting start to a hobby it may be a fine place to start.

Tony

billd6373

Re: holmes twin fan

the panel I saw on youtube was from Harbor and it showed a small fan working well It only drew a little from the inverter

mike95490

Re: holmes twin fan

billd6373 wrote: »

the panel I saw on youtube was from Harbor and it showed a small fan working well It only drew a little from the inverter

What inverter ? Many small fans can run directly from the PV panel. I've NEVER seen a
"small panel * inverter * appliance"
work without a battery somewhere to deal with surges or clouds.

billd6373

Re: holmes twin fan

Thanks for alternate view does this work with a panel and what wattage would it be. The fan I have fits perfectly can It be adjusted

Slappy

Re: holmes twin fan

to use the holmes twin fan, you will need a complete solar set up that will convert D.C. to A.C. For a D.C. fan to run at night time, you will need a battery base solar set up. But just to run during the day time, a panel will work if matched properly. So.........
1) to run a A.C. fan you will need ---> panel, charger controller, battery, inverter.
2)to run a D.C. fan (day and night operation) you will need --->panel, charge controller, battery.
3)to run a D.C. fan (day time only) you will need panel.

and dont forget to add in the cost of proper wiring and fuses. and also on a battery based system, you have to compensate for cloudy rainy days with little to no sun.

so any way you go, it will be very expensive just to run a fan. But all the parts to do any of the steps 1,2 or 3 need to properly matched to work correctly, so it comes to play on your "load" and how and how long that it will be in use?

Shadowcatcher

Re: holmes twin fan

One alternative might be to use computer case fans. Some will do 100CFM or better. I am using two Antec three speed in our Teardrop trailer. My experience with Holmes is lots of noise and very little air movement because of a very shallow blade pitch and poor design.

icarus

Re: holmes twin fan

Shadowcatcher wrote: »

One alternative might be to use computer case fans. Some will do 100CFM or better. I am using two Antec three speed in our Teardrop trailer. My experience with Holmes is lots of noise and very little air movement because of a very shallow blade pitch and poor design.

See post #11 below,,,

tony