Solar heat to heat both Spa and pool

[Billme]

Hi; I'm brand new to pool ownership and this forum.

We have an in ground pool with a spa enclosure, but currently no spa or heating equipment, just a pool pump.

The pump we have is about 5 years old, and made both a lot of noise and sucked down ~13Kwh/day, 8hrs@3500RPM.

I replaced the old pump this week with a new VS pump, and both the noise and electrical use are way down. The next thing I want to do is put the spa area into operation. I'm thinking about reusing the old pump as a spa jet pump, and then adding a solar heating system to heat the spa and pool combination.

The pool is currently plumbed such that the return from the pool pump goes to both the spa area and the main pool. There is a valve that allows me to adjust how much water goes into the spa versus the rest of the pool, wide open it appears to be around 60% to the spa, and 40% to the pool, closed it goes 10% into the spa, 90% into the pool. I'm thinking that if I send the majority of the return water into the spa, and have it flow over the partition into the pool, I can get the spa hot, but also warm the pool. Any obvious problems with this approach?

Thanks,

Bill

 

[JasonLion]

Welcome to TFP!

That approach will never heat the spa up to spa temperatures. You need 100% of the water going both to and from the spa, with no water going to or coming from the pool, in order to get the spa really hot. Also, that approach tends to make the circulation in the pool fairly bad, which can lead to problems.

Your valve should have a setting that sends 100% of the water to the spa. If it doesn't something is broken. It is fairly common for at least a little water to always go to the spa even when in pool mode. But no water should go to the pool in spa mode.

Solar heat isn't great for heating the spa, though it can work. Efficiency drops off quickly as the water temperature goes up, so while it can get the spa up to temperature in the mid afternoon, it requires a fair bit of time and only works during part of the day. Solar is much more appropriate for heating the pool.