[NA]homemade solar pool heaters again[NA]

Let'sgoflying!

Let'sgoflying!

Touchdown! Greaser!
Joined
Feb 23, 2005
Messages
20,316
Location
west Texas
Display Name
Display name:
Dave Taylor
I have a tiny pool, 100' of black plastic tubing, and an aquarium pump. Works well but takes monitoring.

I want to have some kind of thermal switch that turns the recirculating pump on and off so that we are never pumping cold water into the pool.

Can I have a temp detector which senses pool temp and compares it to outflow temp when the pump is off?
Maybe I will just have to have a detector on the plastic tubing?

One problem I see is I can set a simple thermal switch on the tubing to come on at 80F, but once the pool gets up to 80F, I have to adjust it upwards again.
 
Not exactly what you want, but why not a timer set to run the pump between <say> 10 AM and 4 PM. That is probably an 80/20 or 90/10 solution that is easy to implement with a $10 timer.
 
Thanks kyleb. We get unpredictable afternoon tstorms here where the temp drops by 20F and when the pump is running, the pool is unusable by the time I get home from work. Appreciate you putting your neurons to my problem.
 
Dave, they make controllers that do exactly that. We had one on our pool in Ohio for the solar heaters we had. It also let you set a particular temperature so that you could also decide if you only wanted it, say, 80-85F. Additionally, you could set it to cool the pool (i.e. only run when the outside temp gets colder than the pool). Obviously the latter isn't what you want, but might be worth looking into a controller of that sort. No idea what they cost, when we had the solar heat put in that was part of the package.
 
Actually I think I need two sensors so that the differential determines the on and off points.
That only has one sensor.
 
Last edited:
Are the linked sensors water temperature sensors or air temperature sensors? I thought the OP was looking for a water temperature sensor.

Of course, without flow, I'm not sure if a water temperature sensor is gonna give the information you really want, which is "What's the outlet temperature with the system operating?"
 
I was thinking I'd have one sensor in the pool water, and one in the case which holds the solar collector piping (in air but could be plumbed in if needed).
Thanks
 
I can't help you with specifics, but such a device should exist. We had it on a solar water heater system on our house in the Denver area 35 years ago. Once the collectors got to 20 degrees (F) above the storage tank the pumps started. When delta T dropped below 4 degrees (F) they shut down. Worked great. I don't know who Grumman got the controller from. Yes, the system was by the Grumman Iron Works.
 
You must log in or register to reply here.
Back
Top