View Single Post
Old 04-27-21, 04:43 AM   #28
Hong Kong
Join Date: May 2010
Location: Hong Kong
Posts: 108
Thanks: 20
Thanked 17 Times in 13 Posts

Originally Posted by solarhotairpanels View Post
Ok, sounds good and good luck with your new business.

Try to stick with 3/4 pipe because the water will drain back much faster with the larger diameter.

Haven't had any air issues corroding my pipes. System has been functioning now since 2010. System can be flushed with vinegar using a sump pump submerged in 5 gal bucket.

Similar to tankless water heaters your system should be flushed at least once per year to remove rusty water and contaminants. Red hot water passing thru copper creates rusty water.

When building your piping install flush kits. All a flush hit is is a water valve with a shut off allowing you to connect a garden hose to the flush valve. You want to install 2 flush valves total. One on the outbound pipe leading TO collector, one on the return pipe FROM collector.

How to flush solar hot water drainback collector system:
Drain system
Dump 3 gallons of vinegar into 5 gallon bucket
Put sump pump into bucket
Connect a garden type hose from sump pump to pipe (flush valve) that goes out to collector
Connect another hose from collector (flush valve) return pipe back to 5 gal bucket
Turn on sump pump and pump vinegar thru system for 30 minutes
Dump bucket and replenish with fresh water
Run the pump again with the fresh water in bucket to flush out remaining rusty contaminated water

All done!

Take care and don't forget to post pictures back in here of your system especially whatever your plans are for the parabolic setup. Like to see that.
Update here is that I am still working on it. Not many pictures to show just yet.

Right now, part of the focus is on installing ducting in the house, and the pipes for hot water. Since there are 3 floors and rooftop, and all hot water comes from local electric instant water heaters, we need to route the pipes also (for hot water).

The A/C ducting will be built by isolation board (like styrofoam), with wooden on top of it (I think 3/8 inch). I won't even paint the wood, it will be a visible feature of the house. Which is not a bad thing, as the house will be some kind of proof of concept anyway.

Sourcing parts is not easy. We buy from various places, either local shops or online. For several challenges, there are so many ways to do it, and so many products, that the decision becomes hard by simply having to pick parts/methods! Here is an example:

The ducting will have variable control to dampen the flow to rooms where conditioned air is not needed. Also, bathrooms and the kitchen fan will have fans replaced by valves. Sensors of temperature, humidity, CO2 level and more will modulate inlet or outflow valves.

Initially, we were looking at which motor controlled valves we would use inside the ducting. Now we decided to combine louvre registers and valves. This means it will be much cheaper, and also simpler to build and maintain. Those louvres with servo modulation costs around 25-30 USD including register, motor and all. And they are silent (the ducting valves were surprisingly noisy, probably from the gear box).

CO2 sensors will help detect occupancy, and thus guide air where it's needed the most. Humidity will be used especially in bathrooms and the kitchen. And we are working on a solution where one or more sensors will detect foul air, to ensure bathrooms are vented as needed, also when it's not from humid shower air (!!!).

It will all be automatic, comfort, clean air and hot water year round.

And there is much more. Dishwasher will be installed, and it will use hot (solar) water. The same for laundry, it will be switched to dual cold/hot. It will all save lots of energy. And to ensure minimal water waste, a return pump will run in certain cases to ensure hot water is available throughout without having to let the water run for a while to become hot.
Space heating/cooling and water heating by solar, Annual Geo Solar, drainwater heat recovery, Solar PV (to grid), rainwater recovery and more ...
Installing all this in a house from 1980, Copenhagen, Denmark. Living in Hong Kong. Main goal: Developing "Diffuse Light Concentration" technology for solar thermal.
osolemio is offline   Reply With Quote