Solar Heating

This is using solar evacuated tubes

Alternative using Active air system which is very very cheap to build. This system uses solar thermal air collectors, and mates to a district heating system. All it does is heat the INPUT pipe to the district heating system. Its remarkably simple and effective. There is no storage, and a large surface area air to water exchanger is needed. Link

why ?

• Saves you alot of money in running costs for your home.
• Commercial systems are very expensive and also hard to integrate to other systems in your building.
• You can control it from a web browser or integrate it with another system easily because the controller is running open code. Yeah !!

how ?

The solar tubes are very simple. They sit on the roof and soak up the heat energy of the sun and transfer that energy into plumbing pipes that reach down to an accumulator tank (in the basement).

The systems water needs to have glycol ( anti-freeze ) in it to prevent freezing up in winter. Important.

The controller is a simple linux box connected to a temperature sensor and a valve actuator. Its job is to compare the temperature reading from the roof plumbing with a reading from your water tank. If it's warmer on the roof, the controller turns the pump on so that the hot roof water gets pumped into the accumulator and back around. Simple.

The accumulator tanks needs to have copper coils in the top and bottom inside the tank. Warm water from the roof goes into the bottom part of the accumulator. Water from the accumulator (at the very bottom) is pumped up to the solar collectors on the roof.

The top coil is used to exchange the heat into your Domestic Hot Water (DHW) tank (which is pressurised at about 5 or 6 bar) or into your Space Heating (SH) system for radiators or floor heating.

Parts

You need to size the accumulator and solar collector to your needs. You can always add more of both later though too.

Pex tubes are easiest instead of copper, and much cheaper. You can run them down the side of your house into the basement. Just insulate them well and cover in a zinc alum metal to make them look a bit nicer. You can run them down the inside of your house too, but most people dont have a vertical riser shaft unless they designed it in the from the start.

• Pex tube (100 meters). 1000 sek from Dahl [http://www.dahl.se/]
• Accumulator tank (800 liters). 5000 sek. [http://www.alibaba.com/product-free/217150656/AccumulatortankTS.html]
• Expansion tank. Looks like a "football" to handle pressure differentials in the system as the water expands and contracts. [http://www.dahl.se/]
• Temperature sensor on the roof plumbing. Need to find supplier.
• Actuator valve. To open and close the pipe. Just simple Open or Off, not regulated. Needs to have analogue control, so Linux computer can control it.
• Flow sensor. If you want to really monitor the systems throughput. Not required, but nice to have. Needs to have analogue connection so it can be controlled. Looking for supplier.
• Water Pump. 1000 sek from Dahl [http://www.dahl.se/] +. Linux computer for control. Get one with a wifi so you can control it from your web browser.

These guy is awesome: http://www.ourcoolhouse.com/scada.htm