Fans for Greenhouse

[martybg]

Hello I have 12 Box fans that work at 110V like this one:

http://www.amazon.com/Holmes-HBF2010A-WM-Inch-Box-White/dp/B0037W4YD2/ref=sr_1_5?ie=UTF8&qid=1400267009&sr=8-5&keywords=box+fan

From what I found they Each draw 80Watts

that I wanna power completely from Solar with a battery.

Can someone help me to figure out this.. can I power 12 of those fans with

4x250W solar panels + 45 AMP charge controller + 1 12v battery + 1500w inverter

Panels: http://www.ebay.com/itm/Sharp-250W-S...item3a809e26e7

Charge controller: http://www.ebay.com/itm/Morningstar-...item233951bce3

Inverter: http://www.ebay.com/itm/EXCEL-1500-W...item338ef4a641


Also I wanna hook up a thermostat but I don't know where in the chain I suppose to hook it up -> Before or After the Inverter and also What kind of Thermostat do I need.. forgot to say that I wanna make this system 110V AC

and Would it work at all?

Thank you in advance guys.. I'm all for green so powering my g house with this would be great, any ideas would be greatly appreciated!

[SunEagle]

Hello I have 12 Box fans that work at 110V like this one:

http://www.amazon.com/Holmes-HBF2010A-WM-Inch-Box-White/dp/B0037W4YD2/ref=sr_1_5?ie=UTF8&qid=1400267009&sr=8-5&keywords=box+fan

From what I found they Each draw 80Watts

that I wanna power completely from Solar with a battery.

Can someone help me to figure out this.. can I power 12 of those fans with

4x250W solar panels + 45 AMP charge controller + 1 12v battery + 1500w inverter

Panels: http://www.ebay.com/itm/Sharp-250W-S...item3a809e26e7

Charge controller: http://www.ebay.com/itm/Morningstar-...item233951bce3

Inverter: http://www.ebay.com/itm/EXCEL-1500-W...item338ef4a641


Also I wanna hook up a thermostat but I don't know where in the chain I suppose to hook it up -> Before or After the Inverter and also What kind of Thermostat do I need.. forgot to say that I wanna make this system 110V AC

and Would it work at all?

Thank you in advance guys.. I'm all for green so powering my g house with this would be great, any ideas would be greatly appreciated!

Sadly to say you will need a very large battery bank and and more than those 4 x 250 watt solar panels to power 12 of those fans.

Check out this post on sizing an off grid battery design. It will help you get an idea of how big (and costly) it will be to run your fans.

http://www.solarpaneltalk.com/showthread.php?5334-Solar-Off-Grid-Battery-Design

[martybg]

How much more I do not understand? The solar panels will use 950W? I will have 1KW on top of everything the Fans will only work when the temperature is Above 85F degrees

[Mike90250]

So the best thing is to install a Grid Tie system. It will feed power to the grid, and you can use your fans as you please.

OR if you are off-grid, you will need a PV array, battery bank, charge controller, and pure sine wave inverter.

12, 80 watt fans (call them 100w for rounding ease) 1,200 watts You need to put a Kill-a-watt meter on them and figure out what the power factor is, I'm sure it's not 1.0

1200 watts of delivered power, would need about 2,000w of PV panels just to run them. If heat continues past power production hours (3pm) that has to be powered by batteries till the place cools to 85 and the thermostats shut off. We need to know how many hours that is, 2 or 6 hours, makes a big difference in the battery and recharging needed.

A generator may be needed to prevent your batteries from being damaged from deep discharge when the sun is not full.

The power consumed will be for hours, so a stout inverter will be needed, so it will last.

The thermostat(s) should be offset a couple degrees so the entire load of 12 fans does not switch on at once, which may crash the inverter.

This much power, you will need to run a 24V system - you will be pulling over 60amps on the wires at 24V (including system losses)
A 48V system would be more practical, IMHO.

[paulcheung]

First thing you need to find out how many hours a day you need to run the fans, if is 24 hours a day, you will need at least 6kw panels and 800 amps hours battery bank at 48 volts. you are talking about 23kwhs.

Good luck

[martybg]

I'm off grit.

I have put Kill-a-watt and it rounded up to 872Watts the P.F. is 5.4

The RUN hours each day is 6 hours, what kind of backup generator do I need? Can u give me exact generator and installation guide?

What is Stout inverter?

So by 48V you mean that I need 2x24V batteries? What is your suggestion Brand and Model?

So the best thing is to install a Grid Tie system. It will feed power to the grid, and you can use your fans as you please.

OR if you are off-grid, you will need a PV array, battery bank, charge controller, and pure sine wave inverter.

12, 80 watt fans (call them 100w for rounding ease) 1,200 watts You need to put a Kill-a-watt meter on them and figure out what the power factor is, I'm sure it's not 1.0

1200 watts of delivered power, would need about 2,000w of PV panels just to run them. If heat continues past power production hours (3pm) that has to be powered by batteries till the place cools to 85 and the thermostats shut off. We need to know how many hours that is, 2 or 6 hours, makes a big difference in the battery and recharging needed.

A generator may be needed to prevent your batteries from being damaged from deep discharge when the sun is not full.

The power consumed will be for hours, so a stout inverter will be needed, so it will last.

The thermostat(s) should be offset a couple degrees so the entire load of 12 fans does not switch on at once, which may crash the inverter.

This much power, you will need to run a 24V system - you will be pulling over 60amps on the wires at 24V (including system losses)
A 48V system would be more practical, IMHO.

[paulcheung]

When is the 6 hours run? is it during the shining hours? if yes then you are in luck, it would cost a lot less to setup. but if is in the night then it will be much mire difficult.
You said is to cool down the green house, so I am assume is summer time as winter you don't need to cool down. So you will have more sun hour during summer. you can get 6 250 watts panels and 4 6 volt 400 amps hour batteries like the Rolls S530. set up at 24 volts. 1 40 or 60 amp MPPT charge controller and one of the good Inverter which has a battery charger built in like Magnum 3000 watts. Get a 2000 watts generator for cloudy day.

Cheers.

[Mike90250]

Power Factor is always 1 for a perfect system. Motors are always less, usually lower than .85 5.4 is not a power factor.

http://en.wikipedia.org/wiki/Power_factor

A "stout" inverter is like a heavy tree branch that will not break. It's not a brand, it just implys that something is rugged or strong. It will be working hard for long hours, and auto parts store & wallmart inverters, will fail quickly. My guess is you would need a 2,000 watt inverter to run the fans.

48V would be 4, 12v batteries, or 8, 6v batteries, wired in series. These will be large batteries, 12V would be around 100ah, 6v would be 200ah golf cart batteries. These are not car batteries, but deep cycle batteries.

Each solar install is unique, and the loads have to be carefully calculated, so the proper gear can be bought, without making a mistake of under-sizing the system and having to start all over, or overspending for way too large of a system.

That's why we need to know how many non-solar hours the fans are expected to run, so we design for enough batteries, and enough PV to charge them.

When the batteries get too low, the inverter shuts off. What will this do to the greenhouse? That's why you need a generator. Offhand, I would say you need a 3,000watt generator to run all the fans, and recharge the batteries a bit too.

Way too soon to talk about wire diagrams.

[russ]

What are you growing in the green house?

[Robert1234]

I would suggest you take a good hard look at your greenhouse design before designing the solar. Minimize your power requirements first. Doing so will save you tons of pain and $$$. Box fans are horribly inefficient for linear air flow use in green house design. They make some very efficient small fans you can hang in the greenhouse designed specifically for this use. Positioning is also key. Any way you cut it, off grid is going to be very expensive. Good luck.

[Robert1234]

What are you growing in the green house?

A natural question to ask when off-grid and green house are mentioned at the same time

[Mike90250]

What are you growing in the green house?

A natural question to ask when off-grid and green house are mentioned at the same time

It does not really matter, as long as it pays the bills !

[Sunking]

I'm off grit.

I have put Kill-a-watt and it rounded up to 872Watts the P.F. is 5.4

That is not possible. PF or Power Factor is a number of 1 or less. With fans I suspect you meant .54 872 Watts for 6 hours = 5232 watt hours. If you have a 5 Sun Hour day will require a 1600 watt Solar Panel Array, 80 amp MPPT Charge Controller, and a 500 pound 24 volt 250 AH battery.

[martybg]

Can you give me specific links from Ebay?

When is the 6 hours run? is it during the shining hours? if yes then you are in luck, it would cost a lot less to setup. but if is in the night then it will be much mire difficult.
You said is to cool down the green house, so I am assume is summer time as winter you don't need to cool down. So you will have more sun hour during summer. you can get 6 250 watts panels and 4 6 volt 400 amps hour batteries like the Rolls S530. set up at 24 volts. 1 40 or 60 amp MPPT charge controller and one of the good Inverter which has a battery charger built in like Magnum 3000 watts. Get a 2000 watts generator for cloudy day.

Cheers.

[paulcheung]

I don't have a specific link for these parts and also this forum is not allow to provide clickable links. You can go Amazon to check out these parts or google them. if you have a problem for a specific part, you can come back here to ask. I only tell you those part from my limited experiences. Please find out which parts you want and come back here to ask if they can work together before you buy any of them, also the Sponsors of this site has most if not all these parts.

Cheers.