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nicalisa
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# Posted: 16 Apr 2012 12:26am
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hi there everyone and happy belated easter
question for my smart cabin virtual buddies....any ideas for a very low wattage fan to move air from the loft window in to beat the heat in the summer??? It is smoking hot up there winter and summer esp. when the wood stove is going. I am looking for a very energy efficient fan we can place in the window to bring in the cool ocean breeze....
any suggestions?? Thanks in advance eh?
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sparky1
Member
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# Posted: 16 Apr 2012 08:35am - Edited by: sparky1
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Hello
All computers have 12 volt DC fans. some have (4)
they draw very little power, Radio Shack & the internet sell them.for real high speed---go to Car parts place Vehicle radiator Fans 8" & larger-they Move some air too.
sparky1 in s.Va.
also RV vent Fans 40--50 dollars.
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Martian
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# Posted: 16 Apr 2012 09:00am
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Nicalisa, you may find it more efficient to suck the hot air out; the natural convection flow will help. Trying to suck air in means working against the natural flow.
In my "treehouse", it was very warm in the loft until I put in the ceiling fan. Even though the fan was located in the lower area, it helped move the air around.
Tom
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MtnDon
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# Posted: 16 Apr 2012 10:50am
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Part of the question is how much battery capacity and how much re-charge capacity you have or are willing to spend money for. How much time would the fan have to run is another question to figure the battery question? That may be difficult to gauge. ???
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dscrick
Member
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# Posted: 17 Apr 2012 03:43pm - Edited by: dscrick
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I would try and modify an RV vent fan for your application. They run on 12 volts, and there are some highly efficient ones (One brand is the "Fan-Tastic" vent fan). I have a Fan-Tastic in my RV. It's quiet and moves quite a bit of air. Power consumption is low, mine will run for days at low speed and hardly make a dent in the house battery charge. Just the fan running with a few windows open will cool my RV interior very noticeably. I also agree that you want the fan to "Exhaust" out instead of blow in.
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Rifraf
Member
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# Posted: 17 Apr 2012 04:01pm
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SOLAR DESK FAN
http://www.alibaba.com/product-free/115799442/Solar_Fan_DC_12V_Fan_Solar.html
SOLAR CEILING FAN WITH BATTERY & SOLAR CELL
LINK HERE
I just googled the term
12v solar ceiling fan
then clicked on the search images button and looked around.
some neat gadgets out there
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sparky1
Member
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# Posted: 17 Apr 2012 08:04pm
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can't buy (1) must buy in Quantities...
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Rifraf
Member
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# Posted: 17 Apr 2012 08:05pm
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from those folks perhaps, maybe there are other sources to get ahold of similar fans
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nicalisa
Member
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# Posted: 17 Apr 2012 11:56pm
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Thank you all so much for the ideas.
We are going to vent out from the front of the building (small independent solar vent fan with Batteries to run when sun goes down), and then bring cool air in from the other side of the building which is just above the loft.....and on the still side of the cabin from a wind perspective....bad planning I guess on our part.
Our solar array is a series of 20W panels (total 120W of panels) they are located in an area which gives us a half day of full sun and half day of indirect sun. We are running 2 12 volt solar batteries, and have a 3000W inverter (as we plan on adding another 130W panel and 2 more batteries so that we can upgrade sometime in the future to a solar fridge and switch out the propane one to reduce lugging in of propane canisters via boat At this time our inverter reads 12.7 or so.....12.3 earlier in the year, and with where the sun is in May we should be over 13. We run max of about 60W hours total in a full day for our lights (usually run for 4/5 hours for between 3 and 13 watts an hour depending on what we are consuming and much less as the light lasts longer in the day) So we should have plenty for an energy efficient fan which we would need to run for maybe 4 hours in the late evening to cool the loft before bed.
The most energy efficient ceiling fan I found was about 40Ws an hour, and for a small fan to put in front of a window about 30Ws.....I was hoping for something closer to 20W but I may be being too greedy on power conservation
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Martian
Member
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# Posted: 18 Apr 2012 07:32am
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If you want to build a truly solar powered vent, you might try this idea.
Add a chimney to the loft area. Since its not for hot gases you can use pretty much any material like large diameter, light weight, plastic pipe. Build a surround and insulate it. Paint it black. The sun will heat up the insulation and this will create a draw. Put some kind of closure device on the bottom inside the cabin. When you need to vent the hot air, open it, and the heat will be sucked out drawing cooler air in from the outside.
This is not something I've done, but I can't think of any reason it wouldn't work. The hotter it gets, the better it'll work.
Tom
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trollbridge
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# Posted: 18 Apr 2012 08:00am
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That is a good option...it is the same idea as painting the vent pipe coming out the roof of an outhouse black. The black color attracts the sun-the sun heats the pipe- heat creates a draw.
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Bzzzzzt
Member
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# Posted: 19 Apr 2012 09:52am
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Here's just a different idea for summer heat relief. Try a solar powered roof mounted attic exahust fan. Install it and forget it. You can turn most of them on and off with a switch in the attic but most people leave them on all the time. I bet that would work pretty well in a cabin loft.
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groingo
Member
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# Posted: 21 Apr 2012 12:57am
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Look at some building plans of homes from the late 1800's, it is all about convection and sometimes pulling air from under the house.
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SE Ohio
Member
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# Posted: 21 Apr 2012 11:04am
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How about a solar fan?
http://www.lowes.com/pd_269916-228-NPSP8WW_0__?catalogId=10051&productId=3122395&User Search=solar+fan&Ntt=solar+fan&N=0&langId=-1&storeId=10151&rpp=24#BVRRWidgetID
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dfosson
Member
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# Posted: 29 May 2012 09:43pm
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Its been 90 outside and 80 in the cabin. Although it cools down to upper 60s at night, the cabin doesn't cool down quickly. I found these little fans for $15 at WalMart that will run 80 hours on charged batteries that keep the sleeping area cool. Additionally, Coleman provides a battery powered (rechargeable) bug zapper.
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