Solar furnace project needing advice

Discussion in 'The Projects Forum' started by joulian, Dec 6, 2009.

  1. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    I am needing some advice. I have a solar furnace i have built and have come to the conclusion my little 100cfm cpu fan is not enough. I am needing about 200-300 cfm fan.

    Annnny suggestions.

    I need something I would rather run off a solar panel ( say a 50 watt or less) if necessary any ideas.

    My other problem is i have a thermostat that needs to be powered as well.

    Any ideas on how to go about this in a proper manner.

    I had considered an oven hood fan if need be. Its 110 but that would ok
    I have an older spare parts computer i considered using the power supply to power fan.
     
  2. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    Why does a solar furnace need 200-300 CFM fan?? :eek:
     
  3. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Well, I have a 100cfm fan on it now. The room is cooling down faster than its heating up.
    The fan is not pumping the hot air out fast enough to keep up.

    After thinking about it I think something equal to a cheap oven hood fan would be about perfect.

    Anyone got one?
     
  4. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    That must be one screamer of a CPU fan. Most are ~10 CFM or less.

    Ken
     
  5. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    not really its about 4 inches by 4 inches and its pretty quite
     
  6. beenthere

    Retired Moderator

    Apr 20, 2004
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    There must be a basic misunderstanding here. A furnace is typically designed to create very high temperatures, such as for melting metal ores. Possibly, your application is a heater?
     
  7. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Thats what they have called em on Youtube I guess out of habit i am calling that too.
    Its getting up to 200+ degrees so call it what ever you want its free...


    As mentioned in original post.... any suggestions?
     
  8. THE_RB

    AAC Fanatic!

    Feb 11, 2008
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    I still don't get it.

    You say it's heated by SOLAR. But the room is "cooling down faster than it is heating up" so you need a bigger fan?

    Is the furnace the room? Do you want it to be hot? Are you in the room?

    The best I can guess is that the sun heats a "furnace box" then you are using the fan to deliver that hot air to the room you are in as a form of room heating?
     
  9. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    visit Youtube and type in solarfurnace.

    I thought this was the project forum?
    How bout some help on the electronics part of the question.
     
  10. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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  11. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Its perfect. its 2 more dollars than i paid for the 100cfm fan :(.

    Where were u 3 weeks ago ? lol

    the thermostat is just a cheap old fashion style round knob style
    I bought at Home Depot about 2 years ago ( knowing i had something like this solar project in the works)

    Its 24vac
    Similiar to this one.
    http://www.homedepot.ca/wcsstore/Ho...talog/15329.TS321W_WallMount_Thermostat_4.jpg

    Got any suggestions on a solar panel that would power that fan and thermostat?
     
  12. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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  13. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Ah that fan is AC.

    It can be run off DC right? I have taken DC at a local community college this semester but not AC as of yet. That will have to come when i have time or get very experienced at the DC. These projects are just a hobby at the moment.
    I have hooked 3 9v batteries in series to power the fan i have now on 24v's

    I am looking for a simple project ( not sure what it would be called) that would regulate the voltage. For example the solar panel comes into the batteries to store energy and then the simple project monitors the voltage out and like a switch turns off the fan BUT keeps power to the thermostat.

    The 9v's I had on the fan the other day ran down and I noticed after walking back outside 10 minutes later the fan was rocking back and fourth but not able to spin. I came to the conclusion thats not good for the fan motor. Can anyone suggest a simple schematic for regulation. I have a gerneral understanding of IC's from taking Digital...
     
  14. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Hmmm

    No, but i did speak to a tech at the company that produces it the other day.
    Just to make sure I had everything right (my first time hooking one up :) ).

    Lets use this I did a quick Google search for wire diagrams.

    http://farm3.static.flickr.com/2422/3564153071_0be2144a4e.jpg

    He said to hook up the RH ( which is the Heater vAC)
    and the Y for the Air Compressor switch and leave the rest with out anything hooked up.
    In the picture if u look at the HUNTER wiring diagram not the trailer one ( at top ) its just like the diagram in the manual that came with mine.
     
  15. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Ah so i need a relay. I know what they do but i have never built anything needing one so its not always fresh on my mind when trying to figure these things out. I had a Homer Simpson moment when i saw the link you posted for relay :) lol...
     
  16. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    The fan will not run on DC!...only 110VAC The 24VAC transformer is to power the thermostat and the relay.The relay is to switch the 110VAC from a wall outlet to the fan.

    Sorry, the wiring diagram doesn't tell me anything... I'm not an HVAC person so I can't visualize it.

    Solar panels?...batteries?...It looks like you are throwing a lot of different ideas together that are not directly compatible. I think you need an overall plan so you can select components and power sources that work together.

    Ken
     
  17. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Ken

    I am! this is the first attempt at something like this. I am dealing with thermodynamics and electricity and trying to find a favorable medium to make this work to my advantage.
    I am not quite sure where or how ( I am moving it around a little in yard) to source the heat from the furnace just yet.
    It seems when i pump it through a clothes dryer duct hose into a window ( experimental purposes only at this point) the heated air is cooled rapidly before reaching and then exhausting into the room. This data is from some fairly limited sunshine days we have had in the last 4 days other than rain. I have come to the conclusion that this thing needs to be mounted on roof and pipe or hose needs to enter directly into roof with minimal exposure to outside cold temps.

    I think to be on the safe side a 300 cfm would be perfect to compensate for several twist and turns that might be a rather lengthy amount of plumbing to get it from where it needs to be to get the most light to the inside of the house.

    I found this
    https://www.surpluscenter.com/item.asp?UID=2009120809111648&item=16-1383&catname=

    I think this is a better match for what I think i ultimately need.
    Would that transformer work with this and the other things I said need to run off 24v
     
  18. KMoffett

    AAC Fanatic!

    Dec 19, 2007
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    Getting the heat from the collector to the room without cooling through the duct would be my first concern...insulate...insulate...insulate. Well, we're expecting a blizzard and sub-zero temps tonight so insulation is on my mind. ;)

    Are you looking ar DC fans because you want to power them from solar charged batteries?

    Ken
     
  19. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    I think DC is better for me at the moment for several reasons ( sort of mentioned before ).
    I am in south MS so we have uncomfortably cold weather for only about 2.0 months net. I would like to switch as much as possible to solar or something like what I am doing now.

    Your getting what I am trying to do, keep as much power in a battery of sorts ( i am going to start teaching myself next year how to make batteries ) so for example I can store it from a solar panel or some other source of power plant ( perhaps a wind turbine) and then have it where it's supplying something like a fan for my solar furnace or a solar hot water heater or something like that.
     
    Last edited: Dec 8, 2009
  20. joulian

    Thread Starter Active Member

    Aug 27, 2009
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    Ken that relay is a DC relay will that work with the transformer you specified? which is AC...

    Couldn't I just use the thermostat to kick in the fan instead of the relay? Bacically just get transformer and run it into thermostat and then to fan
     
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