Solar powered fan

[rosinante]

Being a pensioner , old , miserable and very tight, would a 40w solar panel drive a fan to ventilate my workshop to have a more of an air flow to help keep it drier , (lots of timber stored in there), I am not worried about temperature.
I know it wouldn't be much but any would help, I have the solar panel already ,or should I just cut holes and fit vent louvres front and back? Or both?
Any solutions , advice gratefully received
Chris

 

[mike os]

louvres would be the simplest and most reliable

 

[123hotchef]

I go with vent louvres too fan would not run at night when the temp drops lourvre would work 24/7

 

[brightspark]

as above put one low down and one high up and u will get convection air movement

 

[123hotchef]

ideally at both ends too so you get some natural flow and maybe the sides as well

 

[rtbcomp]

Low down at one end, and high up at the other so air flows through the building end to end. Put the lower ones on the windward side.

 

[gaz1]

how about this

 

[cumbriasteve]

I have louvres in my workshop, both in the walls and the door and in the correct layout and still get condensation on still winter days.

I am in the process of designing a low voltage, cost virtually nothing to run fan system... well I will when everyone else stops pestering me to do things.

 

[cumbriasteve]

Have a read towards the back end of this thread, the guy's contributed some good advice and suggestions.

http://www.mig-welding.co.uk/forum/threads/wooden-workshop.60901/

 

[rosinante]

Hi vent louvres it is ,fan later if they don't make much difference,
chest for replies
Chris

 

[rosinante]

Another thought, whilst having a d,cogitation it occurred to me that part of one wall of my garage has a lean to green house built against it so my idea is to extract air from the green house into the garage ,my theory is that the air would be relatively warmer than that in the garage and assist with ventilation,the 40 w solar panel can live in the greenhouse along with the fan, I just can't find a suitable fan of about 20w ,can any one help? I have considered a used car rad fan but they are all 80w plus, so any ideas welcome, unless some one has a cart load of computer fans for cheap, Cheers
Chris

 

[gaz1]

have a look at this came across it a while ago

http://woodstoves.forumotion.co.uk/t547-solar-kiln

the other way is via black plastic tubs used as a thermal store

but everything points to a south facing greenhouse and also if the sun is out during the winter months

other than that its use a water heater as a back up plan

 

[ukracer]

Another thought, whilst having a d,cogitation it occurred to me that part of one wall of my garage has a lean to green house built against it so my idea is to extract air from the green house into the garage ,my theory is that the air would be relatively warmer than that in the garage and assist with ventilation,the 40 w solar panel can live in the greenhouse along with the fan, I just can't find a suitable fan of about 20w ,can any one help? I have considered a used car rad fan but they are all 80w plus, so any ideas welcome, unless some one has a cart load of computer fans for cheap, Cheers
Chris

What about the large one of these? http://www.maplin.co.uk/p/80mm-240v-main-axial-fan-yp46a

 

[rosinante]

Hi, done a bit more thinking, also found a job lot of fans for cheap 12v dc, the fans are rated at 38 cu ft a minute at full speed, so assume efficiency of 25% then each fan would move about 10 cu ft a minute,if 4 fans fitted then 40 cu ft min X 60 = 4000 cu ft per hour for approx 6 hours a day ,24000 cu ft
My garage is about 3200 cu ft 20 X 20 X 8 , so approx 7 total air changes a day in addition to that via the new vents, this may be total bo//0x or of some use.
The fans may be more efficient but I am assuming the worst case I think,it's not much but for a few quid better than nothing.
The garage doors are north facing,all three other sides are sheltered by a large hedge at the rear,a fence and neighbors shed on the left and a lean to shed and green house on the right so even when it s blowing a hoolie the garage is in the lee of all three and barely a candle flickers inside even with the doors open.
UK racer that fan is 240v unfortunately, the tight old git in me wants to use my solar panel.
I have made a lot of assumptions so please let me know where I have boo booed ,
Cheers Chris

v

 

[ukracer]

What's wrong with a cheap inverter? ?

 

[rosinante]

I doubt 40w would drive an inverter with a meaningful output at 240v ,plus the cost of an inverter would be more than several computer fans,cheers
Chris

 

[the snooper]

I doubt 40w would drive an inverter with a meaningful output at 240v ,plus the cost of an inverter would be more than several computer fans,cheers
Chris

You would also lose some energy in the power conversion, so wouldn't be as efficient

 

[rosinante]

I have just ordered 8 x 92 mm computer fans from the bay for £6.80 delivered, spec sez 38 cu ft per min at full speed, so assuming they run at 25 % efficiency for 8 hours a day I reckon that I should get approx 8 X 9 x 60 minutes = 4320 ÷ 27 = 160 cubic yards per day, volume of garage is about 80 cu yds so at the least I should get at least 2 air changes a day in the worst case + any natural vent,
The air will be drawn in via the lean to greenhouse with 4 fans and blown out with the other 4 on the other side thru a vent ,now having said all that all of it is my assumption ,if there are any ventilation guys on the forum please put me right,
As said this is all being done for as little outlay as possible which is part of the challenge and I have assumed worst case I think re the solar panel output.


Cheers
Chris

 

[gaz1]

because you have a south facing greenhouse i would have built it like a solar kiln with holes into the garage at the top and also at the bottom other end of the gararge side as that would create natural convection without any electricity needed

 

[rosinante]

Hi ,well job done , bought 8 off 92 mm fans from the bay for six quid delivered, hole made in back of shop, fans super glued to form bank , wiring commoned up and connected to solar panel, fans run even though panel facing West and sun not out today ,so on sunny days they will give good flow and in the summer help with cooling a small bit, also as a natural vent when stationary.
Chris