Delta T Winter settings Questions?

[solarhotairpanels]

Originally Posted by Acuario

Have you measured the entry/exit temperatures of the water passing through the tank? And the temperature at the lowest point of the heat exchanger?

What is the delta across the heat exchanger? The water from the panels should enter at the top of the tank heat exchanger (I assume this is what you have).

If the exit temperature is the same as the temperature at the lowest point of the heat exchanger then you have removed all the heat somewhere in the heat exchanger. Try increasing the pump speed until the exit temperature is slightly higher, then reduce it a little, then you know that you have the maximum possible flow rate to get the maximum transfer from the heat exchanger.

Thanks for the response..
NO, I have not measured temps to/from tank heat exchanger but I will now that you mentioned this..

Water from collector enters heat exchanger at lowest point I believe then returns to collector out the higher side of the heat exchanger. I'll double check that.. next time I go down to the basement.

I like your idea about testing temps at higher pump speed to neutralize in/out temps.. makes sense I'll give that a try. Thanks again for your input.

[Acuario]

If your connections are as you say then they are the wrong way around.
Heat always travels from hot to cold, never the reverse.

You need to feed the hottest water to the hottest point of the tank for it to transfer otherwise you will find the water leaving the top of the heat exchanger may well be the temperature of the hottest water in the tank.

[solarhotairpanels]

Originally Posted by Acuario

If your connections are as you say then they are the wrong way around.
Heat always travels from hot to cold, never the reverse.

You need to feed the hottest water to the hottest point of the tank for it to transfer otherwise you will find the water leaving the top of the heat exchanger may well be the temperature of the hottest water in the tank.

Everything is good.. just checked.
Water from collectors goes to the top connection of heat exchanger / returns from the bottom of heat exchanger.

Been so long since I looked at it.. couldn't remember.
You pursuaded me into putting my fresh coffee down to go check.

good to go!

[dremd]

I’m in no way an expert here, but my guess is you are drawing max out of your collectors by keeping them cooled by your tank thus maximizing collection, maybe some math involving tank outlet / inlet temp and electric cost to run pump is in order. That way you are also taking into account losses in plumbing. Again, I’m no expert.

[solarhotairpanels]

Originally Posted by dremd

I’m in no way an expert here, but my guess is you are drawing max out of your collectors by keeping them cooled by your tank thus maximizing collection, maybe some math involving tank outlet / inlet temp and electric cost to run pump is in order. That way you are also taking into account losses in plumbing. Again, I’m no expert.

Thanks for your input...

so far so good where I have it set right now.

The 2 - 20 evac tube collectors are heating the storage tank water up above ground water temp which is my main goal.

Pump isn't running constantly.. shuts down and cycles now and then.

12 degrees here today and it's coming on then off to accomplish the mission.

I love it.