Here is a system I have been trying this summer. With 5 collectors in a drainback I can keep about 150 gallons of my system around 160- 170 in the summer, easily. In the winter it will be heated by solar and wood. So far I have not need to supplement the DHW this system produces.
Basically when any hot water faucet is turned on a Sika flow switch turns on a small circ to circulate the DB water thru the A side of the HX. The cold well water flows thru the other side and is heated instantly. It takes about 5 seconds to get up to temperature after the faucet is opened.
The next Caleffi I-dronics 11 will be on DHW, here is a preview of some of the concepts.
The 5X12- 30 HX is exactly what I used on mine and it supplies 3 GPM non stop, easily.
The main goal it to not have to store DHW, and eliminate the possibility of Legionella potential in a DHW tank that falls below 120F.
There are codes in Europe that regulate DHW production. Most folks have tankless. If a tank style DHW is used, it must be elevated every 24 hours to 60C (140F) for 60 minutes.
I notice more and more of these pre-plumber DHW heat exchanger systems arriving over here. Viessmann offers a nicely packaged instant DHW HX box to be added to their boilers.
The solar drawing credit: Appropriate Design
hr
Basically when any hot water faucet is turned on a Sika flow switch turns on a small circ to circulate the DB water thru the A side of the HX. The cold well water flows thru the other side and is heated instantly. It takes about 5 seconds to get up to temperature after the faucet is opened.
The next Caleffi I-dronics 11 will be on DHW, here is a preview of some of the concepts.
The 5X12- 30 HX is exactly what I used on mine and it supplies 3 GPM non stop, easily.
The main goal it to not have to store DHW, and eliminate the possibility of Legionella potential in a DHW tank that falls below 120F.
There are codes in Europe that regulate DHW production. Most folks have tankless. If a tank style DHW is used, it must be elevated every 24 hours to 60C (140F) for 60 minutes.
I notice more and more of these pre-plumber DHW heat exchanger systems arriving over here. Viessmann offers a nicely packaged instant DHW HX box to be added to their boilers.
The solar drawing credit: Appropriate Design
hr