Hybrid Car – More Fun with Less Gas

Re: solar heater on flat tar roof

register ::  Login Password  :: Lost Password?
Posted by nicksanspam on November 26, 2007, 2:11 pm
 
 

Using the top as the back? I can't picture that geometry. Greenhouse UV
polyethylene films have 4 and 5 year guarantees. They might last longer
in a vertical orientation or covered with shadecloth in summertime.
Vertical polycarbonate ($.50 vs 5 cents/ft^2) might last 20 years,
with more framing (in 4' vs 40'-wide rolls) and a lot less IR loss.


You might heat water as well, with a car radiator and its 12V fans.


Wintertime solar heating requires height. A 10' tall x 60' long structure
could collect an enormous amount of heat.
 

I'd leave it in place all year.


There might be a vertical absorber inside the greenhouse, eg a few layers
of black fiberglass window screen with house air to the south and solar-
heated air to the north of the screen.


Plastic film greenhouses survive these well if they have steep slopes
or center supports to shed or hold up the snow.


Yes. As an air heater, it might be 2' or 4' deep and 32' long and 8-10' high,
with some sort of ballast foundation vs roof penetrations. Or put a 14-30'
wide plastic film greenhouse or half-greenhouse (a quarter cylinder) with
steel pipe bows on 4' centers over the whole roof. Cheap, at $/ft^2.

Here's one way to heat the house and water (view in a fixed font):

    upper                                      g
    greenhouse                                  l
   |           |                                 a
   |           |                                  z
   ~           ~                                   i     south -->
   |           |                                    n
   |  vertical |       motorized   /                 g
   |    duct   |          damper  /
   |           |                 /
   |           |            day /
   |    |      |               /
   |    v      |              /
   |           |             /   night                    roof
---|            -------------............----------------------------------
   |           .            r            .
   |           . d    room  a           d.
   |           .  a    air  d f         a. f
   |           .   m   out  i           m.
   |    ==>    .    p       a a ==>     p. a <== room air in
   |           .     e      t           e.  
   |           .      r     o n         r. n
   |           .            r            .
    -------------------------------------
               |            |
               | duct to    |
               | room floor |
               |            |
               |            |
               ~            ~

To collect heat, open the motorized damper and run the radiator fan.
To distribute heat, close the motorized damper and run the room fan.
The passive dampers could be plastic film over hardware cloth.

The motorized damper could be polyiso foamboard with an auto windshield
wiper motor and limit switches or Honeywell's $0 6161B1000 damper actuator,
which only uses 2 watts as it moves up to 45 in-lb. The room air outlet would
also have a passive damper that opens out of the page into another vertical
duct or closet to move warm air down into the house.

Here's a simpler way, with 2 motorized dampers hinged at points H,
shown in a horizontal position:

            upper                            g
            greenhouse                        l
           |           |                       a
           |           |                        z
           ~           ~                         i     south -->
           |           |                          n
           |  vertical |                           g
           |    duct   |                    
           |           |                                
           |     |     |                            
           |     v     |                                
           |           |                              
           |           |                                   roof
-----------Hinletdamper|outletdamperH------------------------------
           =\          r           /=            |
           =           a f          =            |
  room     =           d            =            |
   air ==> =           i a  ==>     =            |
           =           a            =     |      |
           =           t n          =     v      |  
           =           o            =            |
           =           r            =            |
            ------------------------|            |
                                    |            |
                                    | duct to    |
                                    | room floor |
                                    |            |
                                    |            |
                                    ~            ~

To collect heat without heating the room, lower the inlet and outlet dampers
to vertical positions to cover the openings (=) below H and block room air
and run the radator fans and a pump to an unpressurized heat storage tank.

To distribute heat, raise both dampers and run the fan and pump.

With 140 F water, we could make pressurized hot water for showers with
a $0 1"x300' 13-gallon piece of pressurized black PE pipe in the heat
storage tank and a simple graywater heat exchanger (eg 2 uninsulated
55 gallon plastic drums) to add heat to the house.

Nick


Posted by nicksanspam on November 28, 2007, 1:57 am
 


I can read them correctly on my unix system and in outlook express,
after selecting text size: "fixed."

Nick


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