Solar heaters - low flow

[mas985]

Also, you should only need to just open the hose clamp a little bit. Not enough so it comes off. Only enough so you can see/hear a leak.

 

[dschembri]

When I do this, its air for the first few seconds until it becomes a water leak if I keep opening further (i guess this is normal).

I did notice however, that quite a few bubbles started coming from the pool. I've left this running like this for a few minutes until all bubbles have cleared, and even backwashed the pool and tried it again.

No bubbles at all now, but still the same really. I'm now trying to test with solar at 100%, and chlorinator valve open at around 30% and the psi is at 16. Does this make sense? Water is definitely flowing through the solar but i cant really measure it to be honest. I can feel warm water from all 3 inlets at the bottom of the pool and can see water passing through on the roof. Maybe I should wait a couple of days and measure temperature change?

 

[mas985]

When I do this, its air for the first few seconds until it becomes a water leak if I keep opening further (i guess this is normal).

Is the air coming out of the pipe or going into the pipe?

I did notice however, that quite a few bubbles started coming from the pool. I've left this running like this for a few minutes until all bubbles have cleared, and even backwashed the pool and tried it again

This could mean it is priming. Did this happen after you opened the pipe?

.No bubbles at all now, but still the same really. I'm now trying to test with solar at 100%, and chlorinator valve open at around 30% and the psi is at 16. Does this make sense?

You are creating an alternate path around the solar so there is less flow rate going to solar and less head loss overall so pressure decreases. But the lower the flow rate in solar, the less efficient it will be and the more heat that will be lost to the environment.

Water is definitely flowing through the solar but i cant really measure it to be honest. I can feel warm water from all 3 inlets at the bottom of the pool and can see water passing through on the roof. Maybe I should wait a couple of days and measure temperature change?

I always figured there was flow to/from solar. The real issue is getting enough flow rate to maintain the solar efficiency.

But for sizing purposes, it is important to know if the plumbing is getting fully primed or only partially primed.

 

[dschembri]

Is the air coming out of the pipe or going into the pipe?


This could mean it is priming. Did this happen after you opened the pipe?


You are creating an alternate path around the solar so there is less flow rate going to solar and less head loss overall so pressure decreases. But the lower the flow rate in solar, the less efficient it will be and the more heat that will be lost to the environment.


I always figured there was flow to/from solar. The real issue is getting enough flow rate to maintain the solar efficiency.

But for sizing purposes, it is important to know if the plumbing is getting fully primed or only partially primed.

I would say the air was being pushed out.

In reality, the chlorinator still needs some sort of flow anyway right. I guess the alternative would be to run x hrs solar only, then x hrs chlorinator, but isnt it more efficient to have both running in parallel?

is there an easy way I can measure the efficiency of the panels? To determine whether I should be decreasing or increasing flow to them?

I currently only check the temperature increase which is good imo - 3 or 4 degrees higher coming out of the panels after going in, but of course it entirely depends on the flow.

 

[mas985]

I would say the air was being pushed out.

In reality, the chlorinator still needs some sort of flow anyway right. I guess the alternative would be to run x hrs solar only, then x hrs chlorinator, but isnt it more efficient to have both running in parallel?

is there an easy way I can measure the efficiency of the panels? To determine whether I should be decreasing or increasing flow to them?

I currently only check the temperature increase which is good imo - 3 or 4 degrees higher coming out of the panels after going in, but of course it entirely depends on the flow.

Is that C or F? 3-4F degree delta is about right. I would get concerned when the delta gets above 5F degrees.

 

[dschembri]

Is that C or F? 3-4F degree delta is about right. I would get concerned when the delta gets above 5F degrees.

That is in celcius. Bear in mind however that is is averaging 30 degrees at the moment during the day (86f).

 

[mas985]

That is in celcius. Bear in mind however that is is averaging 30 degrees at the moment during the day (86f).

Air or water temperature? What is the water temp at the start and end of the solar run period?