On my solar tank for my solar panels , I plan on keeping the tempature around 150 to 160 now with almost 100 feet of copper coil in the tank my effinceny of DMH leaving the tank will be close to the tank temp . So I really dont want 150 deg water headed to the shower . I havent seen to many diy systems that have a mixing valve installed .Well I went ahead and installed one , was it needed ? , just wondering .
Thanks
Jarrod
Hi Jarrod,
It was probably a good thing to do, but...
If you are using the tank for both space and water heating, the tank is not likely to be up at those high temps in the winter when there is a space heating load.
In the summer, there is (I think) not much point in running the tank this hot, as you will pretty much get a 100% solar fraction with a large tank like that if you limit the tank temp to around 140F. Its probably a little easier on on the components and liner to keep the tank a little cooler.
We have a system similar to yours, and have not found the lack of a tempering valve to be a problem. On rare occasions the tank gets up into the 150's. Its not like the instant you turn the water on the its coming out at 160F -- there is cool water in the pipes and backup heater is not going to run as hot as the max solar water temp -- so it takes a while to build up to a temp that is uncomfortable and gives you plenty of time to adjust some cold water in -- at least, that's our experience.
Certainly not encouraging anyone to do something unsafe, and if you have kids using the water, or maybe guests that might be taken by surprise its probably a goo thing to have. I guess this is a good time to put it in while you remember where all the pipes go
Gary
