Solar power panel for shed fan

Hi all,

I am looking into connect an extractor fan (based on the solar panel output) on my shed to circulate the air inside to minimise mould creation. - Air vent on one side, extractor on the other.

Anyone has experience with solar panels or is using one on their shed that could advise me a "good one"??
There are thousands of them on amazon but then again I don't trust the reviews as these can be manipulated and or paid for.

Thank you

 

Have tried the solar pond pumps and unless its strong sun like this week the flow is almost non existance so expect the cheap solar fans will be similar and next to useless as its during the non sunshine times you really need the fan blowing.

If you have mains power in there, some of the larger USB fans give a decent air flow but use little power compared to a mains powered fan.

Have to ask why is mould etc a problem, is it a metal shed ?

 

Hello @NAlberto,
I run al of my fans from solar power. Some are direct connected to run when the sunshines and when it is most needed. Some run on batteries using power collected by solar panels. Some run pretty constantly like the server fans which are 12" diameter. The overhead dc fans run direct but throuh dc timers to cycle on every half hour for about 6 minutes.

I use dc timers to run the server fans at night and some LED lighting. Batteries come in handy

I use solar power to pump water in the bird bidet.

I use solar power to pump water from the rain barrels into the greenhouse troughs which feed the capillary watering system.

All of mine are one brand, Coleman, which is sold at our Canadian Tire stores. I haven't bought any so,ar panels larger than a few watts through Amazon because I like to pick mine up and inspect the packaging to make sure they are in unopened boxes.

If you're worried about the brand, start with a small test one. If it makes you happy, then you know you're okay.

These are a couple of the fans, server and overhead.



This is one small arrays of 40 watt panels. 4 power batteries in the cellar. 2 go direct to fans. I have 3 more 40 watt panels and 4 panels that are 20 or 25 watts which run direct to the greenhouses during the day.

To me, the fans are most needed when the sun shines or when I am heating the greenhouse at night.

 

The Shed currently has no ventilation whatsoever. windows are screwed , the only way to get "fresh" air is to open the door.
"Plan" is to put some vents on one wall, one extractor on the opposite wall and a fan to move the air in the middle

 

Thank you for this @CanadianLori. it does give me an idea indeed. I guess my main issue will be the sun indeed as @ricky101 says, since I live in the UK. I will start small and will go from there. worst case scenario will have to use usb from mains.

 

If you just give the hot air a place to escape (vent) and an opening down low, the hot air escaping will take care of drawing the cooler air in. The same as for a greenhouse.

You just then need a fan inside to regularly stir the air throughout the structure. Those little overhead fans actually make the plants sitting near the floor, wave around like they're in a good breeze. Quite efficient little things! There's lots of little fans that use low wattage.

You'll have fun playing with this project

 

yea that is why I joined this forum to get some ideas, as like yourself, there is always someone that thought about it
My humble shed , I don't have bobble heads in it though

 

From my own experiences of solar panels, but not related to a gardening application.

About 4 or 5 years ago, I put together a system. I'd calculated that for the use I was putting them to I needed 180w. The dealer I bought the items from told me that I was wrong, and only needed 90w. In the end, it turned out that he was wrong, but thats another story..

The system I ended up using was a 90w monocrystalline panel, charging two 75A batteries through an MPPT controller. When the "primary" battery was charged, it threw a switch and charged the secondary. All of the power electrical systems normally used was taken from the primary, and when it was discharged, the switch returned to its original position. This cycle continued.

If I did the same thing today, then I would do things differently. First off, I would use larger solar panels. Not 90w as before, but 360 watts worth. At the same time, I would not use monocrystallines, but the newer Thin Film types. Although at present these are less efficient to the ones I used, they are cheaper and work better in low light conditions.

 

What about trying a simple passive system to start with, such as a low level wall inlet at one end of the shed and an outlet at the other end just below the ridge/apex.
Plenty of low cost suitable fittings at places like Screwfix etc
https://www.screwfix.com/c/heating-plumbing/air-vents/cat840496

If they do not provide enough airflow then you have everything in place to add a small fan.

 

Hi @CanadianLori

As the forums greenhouse solar fan specialist could we ask you what you think to the possiblity of using solar fans as extractors for a greenhouse where conventional top vents are not used ?

Do you use any fans in this way or think there would be enough flow from such fans to remove all the hot air, aided by passive bottom vents ?

 

Hi @ricky101 you can use them for extraction but the big problem is that you are limited as you would be with any other electrical device. You've got to keep it safe from water.

The solar panels are fantastic for hot weather air moving. Simply because the electricity is only generated when needed- during sunny days when the heat builds up.

I use the "passive system" - low down louvers and top vent during the summer. The fans are what really help keep the entire greenhouse modulated. They simply blow/stir every half hour so that all of the greenhouse air gets circulated. And you can bet I haven't seed a spider mite or aphid in there for years.. They (ceiling fans) blow had enough to briskly flutter the leaves.

I also use server fans that gently move the air 24/7 - not strong enough to flutter leaves but keeps the air moving.

And it goes without saying that in the early spring/late fall, this is essential. I keep the openings shut tight and to keep the heat from being trapped at the ceiling they blow the air down and around. When the heater is on, it certainly makes it more efficient. I get the most for my money.
I used some drapery rail to mount it by grinding some holes in the rail and making angled brackets. Let me see if I can find that old picture.

There is an expensive dc fan on the shelf in the back (white and blue) - don't get one of those. Yes they move air but no, they only last a season or so!

I will be moving my panels this summer to the back fence as it gets longer hours of sunshine than the side of the house and I will be changing how they are wired to various devices. One panel will power three different devices/fans for a period of 20 minutes each and every hour during the sunny parts of the day. It is easy peasy to bury the electric because you only need to go beneath the turf and where you will never be digging again.

Because your climate is so much milder than mine, you could literally keep a deep cycle battery in your greenhouse to be solar powered during the day and run fans and lights at night if you want. I have to keep my batteries indoors if I want to prolong their years. You could have the wiring so that 1/2 of the hour it operates the fans and the other 1/2, it powers the battery. I use DC timers - They are so easy to wire. The only tricky part is making all the feed wires look tidy

Oh, and you will use more water - evaporation really kicks in!

 

Hi @CanadianLori.

Thanks for all that, very interesting.

We are half way up the uk and in the lower Pennine hills so do get some cold compared to many others, though not as bitter as your winters.

Actually have a 80ah deep cycle battery as part of a diy aquarium UPS system so could readily tap onto that as its only activated once or twice a year.

What does surprise us is your comment -
"And you can bet I haven't seed a spider mite or aphid in there for years.. They (ceiling fans) blow had enough to briskly flutter the leaves.

As you said earler in this post just on for 6 mins every 30mins, seems amazing if thats all it takes to deter them, loads better than constant insecticides etc !!

A quick search did not show any of your canavan type of fans here, but will keep looking for something similar with a large blade area as its seems the perfect way to stop them little bug....s

Assume your 40W solar panels came with the electronic control box which you just wire up to the battery ?

edit - just found those fans

 

@ricky101 yes, the panels came with charge controllers although I did change out for ones where I can see a reading for how much charge the batteries actually have gotten.


@Loofah lots of homes here have those for ventilating their attic space but they are much larger than the one pictured. They must have a waterproof casing.They obviously would be no help at night or on cloudy days.