Pump and Automation for Solar Attic Heat Exchanger

[Airbus]

I'm strongly considering putting in an attic heat exchanger (Solar Attic) as we have high attic temperatures and by putting that heat in the pool we would also cool our house and reduce air conditioning cost. In theory it makes a lot of sense and our attic/pool stats seem to work well for the system. I'm trying to figure out an automation solution (it operates like solar heating) in conjunction with buying a new variable speed and/or flow pump and would appreciate some insights. I am interested in reliability and were thinking about a Pentair pump. We don't plan on adding a spa or other crazy features. There is an old paragon light that is busted and will need to be replaced at some point and I want it to be able to automate the pool cleaner as well. Phone control would be nice but not necessary. We are trying to keep costs down but want to do it right and future proof.

The cheapest pentair solution seems to be the Solar Touch which (on page 11 of manual linked) states that it is recommended for the Intelliflo VS 3050 (011018) but not for the VF. It doesn't mention anything about the newer VSF pump. Initially I thought that regulating the flow and having a slow constant flow rate through the heat exchanger would be best but after doing some research it looks like a faster rate causes more turbulence which increases heat transfer. Also, I found THIS article which suggests that variable flow pump can be problematic with with solar systems. Other Pentair automation options are the Suntouch (which I have been told to stay away from), Intelliconnect (but I do not believe it works with solar systems), Easytouch PL4 (522355, which should do all but is more expensive). I'm also open to non-pentair automation options.

Please help guide me as to recommendations for a pump and automation system. Should I just get the old VF (011018) pump or newer VSF (011056) pump? Which automation system would you recommend?

I'm excited to join the forum and thanks in advance for any responses.

 

[Jimrahbe]

Airbus,

I have serious doubts that any system installed in the attic will do much to heat your pool.. Logically, it just does not make much sense to me...

In the winter or cooler months, when you need the pool heated, the attic would be too cold to have much heat transfer.. In the middle of the summer, the attic would be hot enough, but then so would the pool...

As far as pumps go, the older 011018 is the gold standard of pool pumps.. It is being replaced with the 011028... Any of the IntelliFlo pumps, except the ones with the SVRS options, would would work for what you want to do..

From the solar point of view, all of the automation systems just tell the pump to run at some preset speed when the solar kicks in...

Thanks,

Jim R.

 

[Airbus]

Jimrahbe,

Thanks for your reply. I completely understand your thoughts. I have had the same concerns. The temp differential, however, is quite significant (at least 20 degrees hotter even at quite cool temps (85 degrees in attic if 65 outdoor ambient). We dont want to be spending loads of money with gas to heat the pool. We just want it to be a bit more comfortable and extend the season by a few weeks. The solarattic company claims that we should be getting at least a 15 degree increase in pool temp. Even if we go from 75 to 85 it would be a big difference. After install the system would cost next to nothing to run. The benefits over solar would be that it is less likely to leak or have issues, would be more durable, no panels in roof, less dependent on sun, and would cool the house better. I’m certainly open to other thoughts or ideas as I haven’t made any firm decisions yet.

Any thoughts on the benefit/need for the VSF over the older VS?

 

[CaptainCannonball]

A failure would be catastrophic... imagine 10k gallons of pool water in your attic. I’d confirm with your homeowners policy that something like that would be covered.

 

[Airbus]

I do plan to check with homeowners insurance. That was my first thought too but not really any different than having pipes through your walls currently. There is only one connection in and out and flexible PVC going to and from (the greatest sight of a potential leak is at connection points). It is a low pressure system so less likely to leak. There is also drip pan with an automatic shutoff.

 

[CaptainCannonball]

I love the idea, especially a gable or soffit mount. I’m not sure how much it will impact cooling of your house if your attic is already insulated, but should give a nice boost to your pool heat. I’m very curious how much heat.

I remember when I was exploring ideas, I even thought about locating a pool heat pump in our attic.