Hybrid Car – More Fun with Less Gas

Solar Air Collector - S run of heatign duct as collector?? - Page 3

register ::  Login Password  :: Lost Password?
Posted by Anthony Matonak on October 8, 2005, 1:49 am
 
 > Some prototype pics here:
 > http://solarsponge.com/prototype/

Brian Graham wrote:

than heating air. Or is this just expediancy so you don't have to use heat
exchanger's, tanks etc. to dump the heat back into the house?


through your unit overnight thereby cooling the house..

It's cheaper to build an air heater than a water heater. It has
fewer parts, works under less pressure and a leak isn't a disaster.

Air heaters are typically more efficient because they heat their
working fluid (air) to a lower temperature and therefore there is
less loss out of the front (and sides, a little) of the collector
because there is less temperature difference inside/outside the
thing.

This particular model is a forced air collector because it uses
fans to move the air. When the fans are turned off, it's very
unlikely any air will move through it. The shutoff to keep from
losing heat at night is to turn off the fans. If the fans are run
from PV panels then this happens automatically.

Anthony

Posted by David L. Jones on October 8, 2005, 11:15 am
 
Anthony Matonak wrote:

than heating air. Or is this just expediancy so you don't have to use heat
exchanger's, tanks etc. to dump the heat back into the house?


going through your unit overnight thereby cooling the house..

Correct, it is not a Passive system.


Thought about that, but PV panels would have a payback period something
ridiclous:
One 50W panel is about AU$00, and at 8hours/day operation over winter
period (say 6 months at best) that's about $/year saving. Payback
period about 60 years!
But on top of that, we already have "green power" which means that all
of our home electricy is supplied by wind or solar anyway! :)
So mains power it is.

Dave :)


Posted by daestrom on October 8, 2005, 3:22 pm
 

All true.  And don't forget that it isn't prone to freezing.

But is there any problem in cold weather with moisture collecting on the
inside of the glazing (or even frost)?

daestrom



Posted by David L. Jones on October 8, 2005, 11:06 am
 Brian Graham wrote:

than heating air. Or is this just expediancy so you don't have to use heat
exchanger's, tanks etc. to dump the heat back into the house?


The thought didn't even cross my mind. I want hot air out, and air
collectors generate hot air directly, so just add fans - simple.
Water, tnaks and heat exchanges etc would add *massive* complexity and
cost to the system.
Efficincy? - doesn't matter, simple make the collector bigger and add
more fan power if need.


through your unit overnight thereby cooling the house..

At the moment, no, haven't had time to add an automatic controller yet.
But I will add a temperature sensor directly to the collector plate
which will switch on the fans when the temp exceeds a certain value.
Trivial circuit.

Dave :)


Posted by schooner on October 8, 2005, 12:00 pm
 Just a matter of adding a snap-disc controller to the fan.



This Thread
Bookmark this thread:
 
 
 
 
 
 
  •  
  • Subject
  • Author
  • Date
please rate this thread