I was asked by one of the folks posting in this thread to add thoughts to this ROI/risk/functionality debate (a great debate I think), since I had written several lengthy posts to one of the more ‘original’ FPH related threads based on a few years happily using my FPH. Before writing I reviewed that original thread, over 200 posts across 13 pages (as of today), plus the 50 or so posts in this thread, and I know there are several other FPH related threads I’ve not yet reviewed. Yikes, it can be dizzying
Here’s my take: Indeed, agreed, the ROI is questionable and at the very least situational. The trade-offs are probably innumerable. And the system can get very complex, especially if you read through all the ways folks have implemented protections for water flow, delayed compressor start, system integration, etc etc. And indeed adding DIY portions from the likes of AliExpress is dicey like everything else from that marketplace.
But for someone like me (and perhaps for bluedolphin), wherein at the time I did not already have another source of pool heat, had a wife who wanted the entire pool (not just the spa) in the 90’s for as many months as possible, who runs AC in Florida basically 7x24x365, who had an older AC unit so no warranty issues, it was
a lot of fun to accomplish that ‘for free’ while reducing my AC costs (admittedly just 10-20%), and reducing the noise from my AC condenser unit (by a lot, nearly silent w/o cooling fan). All for an initial investment of about $4-5K.
Sure we could do roof mounted solar water for perhaps $5K but that only works during the day if the sun is out. Could buy an electric or gas heater for another $5-7K and that works anytime but cost to run is high and rising, especially for gas or propane units, probably soon for electric too. Could do Solar PV and run a heater from that, $30K minimum but useful for other things (unless you use much pool heat and consume all 20+ Kwh heating the pool – and only during the day, on sunny days, when the grid is up, unless you don’t grid connect and/or add another $30-$50K in battery storage.
I might be overstating the numbers above, but in any case I think the largest FPH downside is system complexity. When your AC stops working, *
someone* has to debug the AC, the FPH, the pool pump and any other controls. If you’re smart and that person is you, and you’re home, and you have the time, and you find it ‘fun’, you’re golden. Finding an expert to do that can be another matter. Perhaps the second biggest downside to FPH is, even with 7x24 AC in South Florida, the AC usage is reduced November through February, so FPH gets you 8-10 months or so of that ‘free pool heat’ – not usually all year. That is, unless you add still more complexity to the ductwork to direct / louver the cold air outside when it’s too cool to need AC. LOL. Those are perhaps the two biggest reasons why - when I sold the home with the FPH - the new owner tore it out.
My newer home already had an electric pool heater so the FPH ROI is less favorable and I’m not likely to add FPH. But I have a new idea that is much less expensive so I’ll start a new thread on that soon.
That FPH ‘original thread’ I referred to is here:
Hotspot FPH AC heat reclamation pool heater - a review!
Thanks to all for all the contributions. Happy decision making! -- Joe
. They laugh uncomfortably when I tell them my plans because they are not sure how serious I am ….
