Hotspot FPH AC heat reclamation pool heater - a review!

[setsailsoon]

Actually I made a typo, it's actually 12-24 v I believe. I would think it just inserts the signal to the existing data stream in the Pentair format. But that's just a guess. You could probably see if it has a connection for the RS 485 input also. That might indicate it could take both. On my V-Green motor digital inputs have priority over the internal timer. The manual is a little fuzzy on how serial inputs fit in but it looks like they could take second priority to digital and higher than internal timer.

Chris

 

[drglanton]

The brain was mostly as supplied by the FPH folks - a "PID" that you set to desired temp., then it senses pool temperature and drives some relays, some that are internal to the FPH control box and other relays and valves that must be installed in the AC condenser unit. (A relay added to the condenser unit also feeds back to the FPH to tell the FPH controller that the AC is running).

How close to the AC unit is your pool?

Where did you position the thermastat on the FPH? At the AC or closer to the pool and pump?

 

[kmheid]

What do you mean works well MOST of the TIME> Why have you chose not to use it with your VSP?

I use the automation control cable from my VSP to the Intermatic Z-Wave controller, so I can use automation to control my pump. My pool never gets too hot, even with 2 FPHs, so I leave them on all of the time unless I don't have my pump running, and then I manually turn them off.
A couple of times, my pump stopped unexpectedly because there was a problem. That caused my compressors to overheat, and shut down. I only knew there was a problem because the house was getting warm. My HVAC contractor installed some safety switches on the compressors to shut them down if this happens, but they must not be installed correctly because they have never proactively shut down the compressors. It has always the internal compressor safeties that get triggered. If things are running properly, this is not an issue.
Overall, the system has worked well for me. I mostly only use my gas heater in the spring and fall. My pool gets a decent amount of shade, so I keep it covered when not using it and it stays comfortable. During the 5 or so hottest weeks, I leave it uncovered. I feel less guilty about running the A/C, and the pool stays at a more comfortable temperature.

 

[drglanton]

I use the automation control cable from my VSP to the Intermatic Z-Wave controller, so I can use automation to control my pump. My pool never gets too hot, even with 2 FPHs, so I leave them on all of the time unless I don't have my pump running, and then I manually turn them off.
A couple of times, my pump stopped unexpectedly because there was a problem. That caused my compressors to overheat, and shut down. I only knew there was a problem because the house was getting warm. My HVAC contractor installed some safety switches on the compressors to shut them down if this happens, but they must not be installed correctly because they have never proactively shut down the compressors. It has always the internal compressor safeties that get triggered. If things are running properly, this is not an issue.
Overall, the system has worked well for me. I mostly only use my gas heater in the spring and fall. My pool gets a decent amount of shade, so I keep it covered when not using it and it stays comfortable. During the 5 or so hottest weeks, I leave it uncovered. I feel less guilty about running the A/C, and the pool stays at a more comfortable temperature.

Thanks for the feedback. I am close to making a decision. Do you have any pics of your system?

 

[drglanton]

I took the plunge and am installing the Hotspot FPH and a new air conditioner at the same time. The AC techs just came to my house yesterday to look at all the equipment and review the installation guides. There seems to be quite a few things that are "field provided". Meaning someone has to go buy them. Having new AC unit moved about 20 feet from pool shed so my water runs shouldn't be too long. I have a shady pool that I estimate is about 15,000 gallons. Live in Michigan and last year had roughly 2 days the pool got to 80. I know I should have a solar cover but I hate them. Hoping this can keep my pool useable during the summer months without a stupid cover. I will update what looks to be a complicated install process once more has happened. I will also uploads some pictures if this site allows it. This thread was helpful and convinced me to give it a try.

How do you like your system? How is it working out for you?

 

[drglanton]

I live in Tampa, FL and had the hotspot for about 6 months. We did have compressor going bad during that time, so the FPH probably was not working at optimal efficiency. The compressor was not maintaining constant pressure.

After we had the compressor replaced....UNDER WARRANTY (House is 3 years old, just had to pay for labor). The FPH dumps a ton of heat into the pool throughout the day.

Yes there are temperature set points, which can be modified up or down.

Yes I would install it again, but with caution:
1. You need an expert installer, possibly commercial experience. One that understands that you will call them a few times after installation for questions, assistance, issues, etc. It tool a few questions back and forth between HotSpot, me, and the installer to get it dialed in.

2. You need to monitor the hotspot and the installation to ensure its dialed in and working properly. After the compressor was replaced, Hotspot is on autopilot.

3. Collect data before you install and after. Every location and environment is different. for example, the orientation of your pool (ie north, east, west, south), amount of shade, screen or not, location (ie. FL versus Colorado cannot be compared) etc.. So everyone's results will obviously vary. For me in Tampa FL, I wanted to not only make my water comforatable during the swimming season (ie +4-5 degrees), but also wanted to extend swimming season to almost year round. I think now that its dialed in I will definitely almost get year round swimming.

4. I have heavy Hayward automation. So we added a independent pump for the HOTSPOT. I've seen some, that just have their primary pump run 24/7 on low speed, but I don't like that idea for various reasons (ie if you have a heated spa...the temp will exceed safety margin for cooling Freon, running the pump 24/7, etc). I didn't like the way it was plumed to the same outflow pipping to the pool, bypassing the filter and working against my primary pump when on. So I took a Saturday installed a separate filter for the FPH pool pump we installed and also isolated the outflow return to the ones on the floor. The extra filter was great idea, as I get extra filtration while the FPH pool pump is running This great, the primary pump does not have another pump creating head pressure, I visually see the water ripples from the bottom pipe...telling me the FPH is on, it also concentrates the heat better (higher temp on the outflow the better, the other way diluted the temperature), and now my automation/spa has no issues (we could not use the FPH during spa mode, so we either turned off the A/C inside or turned off the FPH controller....no we don't need to do that).

5. Ensure you install a Water FLOW cutoff valve. It does not come with the HOTSPOT FPH but the controller does have a spot for the cutoff wires. This will ensure that if it does not sense water, the controller will default to AIR COOL on the condenser. This would essentially stop any of the overheat complaints from the other post. I learned this from oneamaruluv...he is also here in Tampa, and we worked together to get out systems dialed in....by sharing in lessons learned.

- - - Updated - - -

All my neighbors love our constant water temperature in our pool water, and are looking into getting a HOTSPOT FPH. Especially, since they had issues with their previous solar installation due to roof leak.

I will tell you that its comparable to solar heat. My other neighbor has solar heat, and he an I are always comparing temps. His pool faces south (all day heat) and mine faces north (and shade from house). So I still think I come out ahead, as he has an advantage with all day heat from the sun.

Once we get into the cooler months, we will determine which works better between the two. Again our location is Tampa, Fl....which is crucial to understand, that there are several variables to consider....not each installation or application is the same.

What size shut off value? Where did you install it? How has it been working for you ?

 

[xr4ticlone]

Ok, without going through 9 pages & trying to piece together an answer I figured I'd just ask.

We're in San Antonio. 11k +/- gallon pool that is way too often in the shade. Only 5ft deep and much is 3ft.
A/C is 3 years old but basic unit, not a HE model 5 ton. We have updated insulation & radiant barrier in the house. 2800 sq ft, most of it 2 story.

Even after a week of 90+ degrees the pool was 76 degrees last night...in mid June. : (

I know that it'll heat up the pool. But realistically how much, if any, will it cut A/C bills?

We don't know how long we'll stay in this house, possibly looking to leave it in two years & build outside of town. I'm guessing it's going to be $3000 to install. I'm not sure if it would make sense taking the unit with us or or not? Highly doubtful that we'd have another pool in the shade like this one as we'd have land and pick where it went.

But right now the pools isn't much fun to be in much of the year...which is stupid given where we live. I think we'll do it regardless, I'm just curious if I should expect any savings.

Thanks in advance for your time & info.

 

[Joshii]

I don't think it's worth it for you. You can't take it with you, mainly because of the surgery you do to the AC, it won't significantly reduce your AC costs, and you would be way, WAY better off just getting a $150 solar cover. I imagine the biggest issue with your pool temp is evaporation.

 

[nuttyp]

There is a wealth of info in that 9 pages, but I'll bite with a quick answer too I agree with Joshii, it won't be worth it. As stated somewhere in the volumes above, I got about 17% savings on AC cost. Knowing what that really saves you means knowing what % of your power bill is due to the AC cost (the condenser/fan unit cost specifically). Let's be generous and say it's 15% savings of 80% of a $300 monthly bill, you might save $400/year - ROI break-even is perhaps 10 years.

I'd be jealous if you got it all done for 3K, as mine was 4K many years ago and I did a lot of the work myself. Except for the folks who discussed building an FPH from scratch with parts, I'm guessing at least $5K or 6K soup to nuts, pushing the ROI to 14 years. Of course that only compares to a "do-nothing" scenario - it does not include more savings from alternatives like installing an electric pool heater or a passive roof system.

I'm with Joshii too regarding "taking it with you". Then you have to pay for removal and reinstallation at the new place, which might be $2K on each side and ROI starts over. That said, if I knew the guy who bought my home was going to rip it all out to install a HE system, I might have considered taking it with me or at least asking him to save the parts for me after removal.

I too had some luck with a solar blanket, saving a few degrees of loss every night from evap/heat loss. Rolling it out daily leads one to getting a reel assembly and that all tends to work out. Downsides being the appearance when it's covered, the reel mechanism appearance/obstruction when it's covered or not, and the deterioration of all that over a couple years. Also tried one of those chemical "liquid solar blanket" things that allegedly dispenses a film to slow heat loss at night, that did not work at all for me.

My last solution was to purchase a home with the pool unshaded and south facing (in south FL). That helped a LOT, but I might still add some clever thing for the coolest nights - Nov thru Feb more or less.

Good luck!

 

[xr4ticlone]

Our A/C runs from March to October (clearly much more in the summer). I'm guessing we could have a 80 degree plus pool for most of that time given the small size?

I figured ROI was going to be low. But the pool is a weird shape and putting a cover on it would be a PITA given the waterfall and how little room there is around the other sides.

I suspect that it'd be a selling feature, but at the same time it's a hard feature to sell...so???

I just have zero room for a solar heater, don't want to spend a fortune heating it with gas, don't want to F around before every swim with some other heater.

 

[nuttyp]

Understood, xr4, good thoughts.

Yup, I think the pool covers are a pain from almost every vantage point. They work to some degree, but have so many issues and downsides. And even with a 10 year warranty on a "high quality" one that you manage to cut to fit, clean and retract and reroll daily, they last 2 or 3 years and plead for replacement. Just my opinion of course.

Our scenarios are not so different from one another, just that your cooler season is perhaps a bit longer in San Antonio than mine in Naples FL and my pool is south-facing so I need far less heat. Anyway I would fully expect your statement to be true, that you could get an 80 degree or better pool temp for most of that time. And much higher for a lot of that time if you wanted to. We like our pool at about 85-86, but for fun we set our FPH up above 90 for awhile - my wife wanted the whole pool to be spa-like - until we decided that was less refreshing and set it back down. Of course the higher settings work well when the AC is running a lot.

Then I think the question becomes, and ignoring a bit of ROI from the AC savings, do you want to spend 4-5K in order to swim comfortably for 8 months or so "for free" (less than zero runtime cost), and not use the pool for the other four months? In an ideal case, you might also have that gas or electric heater as backup, only using it when desired and/or needed, or if you had a spa you wanted to heat quickly. Of course, tack on another 4-5K plus runtime rates.

Before we moved from the FPH home (east facing pool with the same problem you have), in the winter and if folks were visiting I would heat the pool using FPH by running the AC more so the pool would be comfy when we had guests from the North - and maybe open the windows/doors to warm the place up while keeping the AC on. I considered getting fancy (geeky) and installing a plenum damper that would redirect the AC airflow outside so I could have pool heat in the winter, without adding another heater and without freezing us out of the house. But that seemed like overkill, or else I just never got around to it.

Having sold the FPH home, now I'm in a new place that came with an electric pool heater but of course no FPH. And I've been asking myself that same question, do I want to spend 4K on FPH to slightly extend the swimming season and to avoid using my electric heater to do so. So far my answer has been "no". But here, with a south facing pool, we swim daily in June in 85-86 degree water without any heat. (maybe only 80 if I hadn't run the heater to get it to 85, but then it stays at 85 for many weeks now). But in your situation with a pool that won’t self-heat much (and/or loses too much at night), I think I would go with FPH. Well, that's what I did when that situation applied to me.

And it only took me three home purchases to figure out that next time a South facing UNshaded pool was a requirement. We find, especially during these troubled times, a daily swim is really REALLY good for the soul. I have a neighbor who refuses to buy a pool heater unless his wife commits to swimming in it. She says she won't swim in it unless he heats it. They have been stuck on that for several years I hope a solution works out for you.

 

[Joshii]

xr4ticlone, the FPH will work great for you. But you will never "get your money back" if you're planning to move in 2 years. If that's not a factor, by all means go for it. It will work and do exactly what you want it to. Just don't think of it in terms of ROI. It would be an investment in your happiness, not your bank account.

 

[Soupy]

At that point, a traditional heater might be worth considering.

 

[NJdiy]

Hey guys. Up here in NJ. 26 K gallon in ground at least half shaded. Looking to DIY this FPH thing. House ac is 5 tons. Found all parts. Can anyone share the installation manual for ac (not heat pump). Thanks a million !!

 

[swamprat69]

As an HVAC tech I would be curious if anyone could post an Installation/Service manual for the FHP. Due to retirement and Covid-19 I have plenty of time to peruse it ( also my poker rooms haven't reopened here yet )!

 

[drglanton]

Glad to share this schematic I created based on the manual.

 

[jerryt]

Kmheid "A couple of times, my pump stopped unexpectedly because there was a problem. That caused my compressors to overheat, and shut down "

I was very uncomfortable not to have a pump failure safety device for the FPH. I have a Condenser with two separate compressors and so I run two different pump speeds. I have added; 1. current sensors that verify that a pump is running, and 2. a automatic switch over to pump two in case pump one fails and 3. liquid line temperature controller which shuts down the compressors in case of pump or fan failure, and also 4. a water flow switch.

Something to realize. When the FPH switches from water cooled to air cooled, freon is trapped in the FPH balance coil (Water cooled condensing line), so the compressor(s) run lean as it takes a few hours of running for that freon to be recovered back into the air cooled condensing coil. So I try not to have the unit switch back and forth between air and water often...

I have Brultech Energy monitor graphs of the compressor(s) running after switching modes and the compressor current draw drops for a few hours as the freon is recovered. 20% drop in watts, slowly returning to normal current draw as the sight glass shows the charge returning. Also you can see the sweating of the balance coil where the liquid freon was trapped.

@ Swamprat69 - Attached original install manual.

 

[swamprat69]

I did note at least one ommision in the section about brazing refrigerant lines that is essential as good standard practice that most homeowners are not aware of and many HVAC contractors do not practice regularly. When brazing copper refrigerant lines a low reactivity gas such as Nitrogen or Carbon Dioxide (with a constant flow rate) should be used to purge air from inside the system and prevent cupric oxide from forming inside the copper tubing. This is especially true with the newer refrigerants that use POE oil rather than mineral oil as a lubricant, as POE oil tends to dissolve/loosen cupric oxide to form sludge/gunk that can plug parts of the system that are restrictive and can also be abrasive to parts of the compressor. This should be standard practice on all refrigerant systems! Please reference this for more information. http://www.rses.org/assets/rses_journal/0714_Nitrogen.pdf

 

[swamprat69]

Thank you guys for the info provided.

 

[NJdiy]

Thank you guys for all the help. So far the hardest part to find is the pump out flow resistor. Any ideas where to find it ? Also a few of you installed a flow sensor cutoff. Which flow sensor to use ? How did you install it and where does it connect to the FPH controller ?