Carlb,



Carl, how do you dump your heat in summer.?
My plan is to tarp cover the panels. or...push the heat to an external radiator mounted on the outside wall.

Veggie

With the angle of the shed and parabolic trough they are most efficient at winter solstice so they are much less efficient in the summer.   the controllers have high limit settings and will turn off water flow to the parabolic reflector and shed wall when temps reach the high limit.  Sitting stagnate will not hurt the parabolic trough.  In the summer i usually just turn off the linear actuator and leave it sit facing east and it will only add a little amount in the very early day.   The shed wall will provide all of the hot water needed in the summer without the use of the parabolic trough.  Again with the angle it isn't all that efficient in the summer     

our two air heaters are powered by small blowers .80 amps @ 115 vac  each.  The design does not take a lot of power to move the air since convection is doing most of the work.  Good sunny day outside temp 25 degrees F  indoor air 72 degrees output from air heater at 100 cfm is 145 degrees f.

its a 21" linear actuator that i got for  30 dollars and a Tiny Tracker for the electronics.  the tiny tracker works great.   I could afford to move the mounting point on the actuator to get a little more travel but it is only missing about 1/2 hour of sun in early morning.  I have some constants based on the location of the trough to the house but it was my best option for the installation.   The collectors are feeding a 275 gallon tank in the basement.   I decided to opt for keeping the collector close to the house to minimize heat loss moving the water from the basement to the collectors.  Both are drain back systems 

I only use it to preheat our domestic hot water, the tank has a 250' copper coil in it that city water circulates  through heating the water before it gets to our electric water heater.   While we have natural gas at our house we generate so much electricity with our solar (33 Mwh a year) that we never need to use natural gas unless the outside temp dips below 0 degrees F or we get freezing rain which renders our air source heat pump almost useless.

We also have about 150 sqft of solar air heaters which do a fantastic job of heating our house during the day in the winter time.   On a sunny day at 25 degrees f outside the house (2675 sqft not counting the basement)will heat to 74 degrees by late afternoon. solar air heaters are very easy to build and very inexpensive. I have had zero problems with them.  I built the first one in 2004 and the second one in 2006

I took a few pics of my 8' x 12' solar shed wall and 4' x 8' parabolic trough I will try to upload them.  

http://s1203.photobucket.com/user/carlb2323/library/?sort=2&page=2

Hi Carl,
I'm not surprised that you have a DIY, technically savy solar hot water setup; your projects are always smart, and technically impressive.  Reflector systems have the advantage of being able to produce useful temperatures on hazy or cloudy days (at reduced rate), which my flat panel doesn't. 

What did you use for reflector material, and did you glaze over the parabola or leave it open?  Did you use evacuated tubes?

Bruce

The reflector is made from 4 2x4' mirror grade stainless steel sheets. the parabola is not covered and i couldn't get an 8' long evacuated tube so i encased the receiver in a Borosilicate Glass tube sealed it up good at both ends  and vacuumed the air out with a air conditioner vacuum pump to 10" of vacuum.
i has leaked some of the vacuum out but it seems to have stabilized at 6" which is fine by me.  I am using a simple cheap Chinese pump (12 dollars) with a cheap adjustable voltage regular (less than a dollar) to adjust the dc pump speed for optimal heat transfer and flow. a simple old laptop power supply is more than enough to supply the pump.

I would remove that doghouse from on top of the generator and mount it on the elsewhere where it wont get shaken to death.

While i have no issues with starting my lister with the de compressor i will not attempt to try to start it without it for fear of breaking my arm or something else.  That being said we only use our lister for backup and i have an air starter on mine and 100 gallons of compressed air on hand at all times.

Sorry low gear i was looking at Bruce's post lol.