Real world results say otherwise though. In the morning, the water in the water heater is around 60-65, after morning showers and stuff, (the geothermal will heat it up to about 110-115 during the night). The temps are freezing outside and as the sun heats things up the system will run off and on till it stays on continuously. This is when I have the aquastat set to about 80 degrees before it will turn the pumps on. So it is actively taking it from 60-65 degrees up to 85-90 degrees. This is more than 2 degrees.At the rate you are pumping you can only can only raise the temp 2 degrees if you have a square meter of collector which you do not have. You need to use a PWM speed controller for the pump, not a potentiometer. Your heat exchanger needs to be insulated too.
Right now I have it hooked up like this (see drawing).This heat exchanger is configured to be hooked up with either concurrent flow direction or counter flow direction. I have it set up for counter flow connection right now.I agree with collector is to small, needs insulation, needs glass, also make sure your flow is correct through the heat exchanger. Solar input ( hottest fluid ) should be at the hottest water. Mine is DIY tube in tube with flows in opposite directions.
Second loop built. Should have it hooked up tomorrow.Hello to any one who reads this! Lol.
I built my first solar water heater!
It's 1/2" pex under a piece of Polyethylene terephthalate glycol, or PETG plastic.
Inside the pex I have RV fluid/antifreeze so it doesn't burst at night with freezing temps. I have an Aquastat attached to the pex loop so the pumps won't turn on till the loop temp reaches a user defined value. Currently i have it set to about 85 deg F. The RV fluid is pumped through the loop via a solar powered pump to a plate heat exchanger. On the other side of the plate heat exchanger is the domestic hot water. I have two water heaters connected in series and the first one is turned off. The water from the first (powered off) water heater is what is pumped through the plate heat exchanger. I was hoping to use this setup to heat or at least pre-heat the hot water. I suppose i have half of that goal accomplished because it will circulate and get the water temp in the first water heater up to about 87-90 degrees.
My question to all of you: if i build a second loop and connect it to the first would it get higher temps...
A) if connected in series with the first loop
B) if connected in parallel
Or
C) won't matter, thats the best temp I'm going to get?
Side note, cause i know someone might ask. The piping in the photo also goes to our geothermal hvac system. When it is running it heats the domestic hot water. I have check valves on each side so the geo won't pull water backwards through the plate exchanger and vice versa. Typically, right now in the winter, the geothermal heats the water at night and the solar loop heats it during the day because the geothermal doesn't need to run during the day.
I appreciate any feedback good or bad. And thanks for your help!
I've learned that i can't get true parallel flow unless i do what's in the attached drawing. So I'm going to connect in series.That is what I would expect from the piping. Is there room on the right of the first. Then tee where piping is balanced. Parallel with give you the most capacity. Series will produce the higher outlet temperature but will not produce as many BTUs. The colder the entering water the more BTUs it will absorb. I don’t recall is this a open system or closed. If it is closed be sure to have a T and P valve and expansion tank. Mine is basically open (2 lb pressure relief) in the summer when it boils it sounds like a kid practicing on a horn.
I'm not sure what you mean. The temps i just talked about are normal temps for where i live. Its really cold outside, i feel like anything above 95 at the water heater is good enough for the middle of winter.I have researched but never used vacuum tubes but you should look at adding some in series if those are normal outside temperatures.