Another try at discussing swimming pool heat exchangers

Discussion in 'Swimming Pools and Hot Tubs' started by Waukman, Jan 16, 2009.

  1. Waukman

    Waukman Member

    WaterFurnace IntelliZone operation question

    Here in Wisconsin we hit a low of -18 and the system finally hit the point where it couldn't keep up. I got up this morning and the desired temp of 75 on the first floor was not held (we had dropped to 73). The short story and question is:

    Specific details:
    Zone 1 (1st floor) Making a call for stage 3 heat
    Zone 2 (2nd floor) Making a call for stage 1 heat
    First floor setpoint 75, actual temp 73
    2nd floor setpoint 70, actual temp 70

    I found that if I made a call for 2nd stage heat on the 2nd floor THEN the zone unit would make an emergency heat call. It would seem that something is configured wrong on the zone unit. I don't see many settings that might impact this. The zone unit has the zone percentage settings and currently both the 2nd floor and the 1st floor are set the same at 70%.

    Anyone have ideas? Is this a configuration issue or is the zone unit defective or is this the expected behavior (which I wouldn't expect since it means that a zone would drop below the desired set point).

    Ok, the software engineer in me is digging deep into the intellizone install manual. It discusses staging options. It is currently set to Normal (as shipped). I see it talks about Faster with timer which leads me to believe that if I select this staging option it might engage the electric heat if only one zone needs it. However, the documentation puts in bold that this be avoided. Anyone have details on the exact operation behaviors for the various staging operations?
  2. engineer

    engineer Well-Known Member Industry Professional Forum Leader


    Running stage 3 is really expensive so perhaps Intellizone won't call for it until more than 1 zone requires it.

    It has the ability for quicker upstaging that might get you what you are after - aux heat for only one zone.

    Looby recently posted a link to Waterfurnace Engineering docs - navigate it to find Intellizone info.

    If you are not comfortable changing dip switches, please don't - review the docs - and request your installing contractor to make the change or suggest other options.
  3. Waukman

    Waukman Member

    I would think it wouldn't operate that way since it could allow one or more areas to drop below the desired setpoint, as in my case.

    I assume that is the staging options discussed in the DIP switch setup section of the install manual. The problem is that the manual fails to go into detail. The options are: Normal, Quicker, Faster, Faster with Timer. The manual discourages Faster with Timer. If I choose quicker will it allow the electric call to happen if only 1 zone is needing it? The documentation fails to say.

    :D I am a embedded engineer by trade so I play with hardware on a regular basis. That is why I have the cover off the zone unit as I want to be able to 'see' what the system is doing. So flipping dip switches....
  4. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    I remember skimming the manual and seeing that a quicker setting lowered the aggregate zoning percentage needed to upstage from 50 to 40 percent. Not sure that is relevant to your situation or applies to aux heat

    Another option might be to deemphasize upstairs zone to the 45% setting, allowing downstairs zone to dominate the aggregation calculation

    I always power Intellizone down before messing with dip switches - not sure necessary but seems prudent. Avoid the one marked "release factory-installed smoke"

    Also keep this timeless general tech support advice in mind:

    Alles touristen und non-technishen looken peepers! Das machine is nicht fur der fingerpoken und mittengrabben. Is easy schnappen der springenwerk, blowenfusen und popencorken mit spitzen sparken. Das machine is diggen by experten only. Is nicht fur gerwerken by das dummkopfen. Das rubbernecken sightseeren keepen das cottenpiken hands in das pockets. Relaxen und watchen das blinkenlights.
  5. Waukman

    Waukman Member

    I have heard from my installer and he contacted WaterFurnace directly. It seems the system is operating as intended. If a zone system is setup ALL actives zones must be calling for at least a stage 2 heat before one zone can call for stage 3 and have the Aux heat unit enabled.
  6. Boomer

    Boomer New Member

    I saw a couple of post last year on swimming pool heating. I live in NW Florida and am ready to start designing a system for my house. I studied Andrew Chaisson, P.E. article from the Geo-heat center and he hit on exactly what I want to do. I need about 4 wells to cool my downstairs 3.5 ton area. Because of my Southern latitude, my system loads will be cooling. So I desire to reduce my wells from 4 to 3 by passing my GSHP exit water through a water-water heat exchanger at my pool center (right outside the house where the well loops will pass). I would think I would wire the pool pump to run whenever the GSHP is running in the house-cooling mode. I have searched the internet and see some heat exchangers mostly discussed in terms of heat pumps. Does anyone out there have experience with pool-as-a-loop design? I've heard of flat plate and tubular heat exchangers...but who knows how to design there usae in GSHPs?
  7. hardchines

    hardchines Member Forum Leader

    If you decide to do it,I bought a heat exchanger for a job some years ago and never used it, paid about 6K, its yours for 2K. + shipping if you want it. I would think your pool will get pretty warm pretty quick, and in the south it would remain hot,sorta like a real big hot tub. :p JMHO.
  8. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Running a pool pump whenever unit is on in cooling may result in many many more hours of pool pump operation than necessary for filtering pool water. Pool pumps use lots of power and some are oversized, underpiped, or both.

    You could wind up with a system substantially more costly to operate with limited benefit

    A modest flat plate heat exchanger should suffice, and I would look into a much smaller pump dedicated to circulating pool water for the geo only. Perhaps tee into your present piping and add a check valve to avoid short circuiting the water
  9. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Sounds like you have a good grasp of the issues.

    I don't agree that a 3-4 ton GSHP typically needs a 1 hp pump for closed loop circulation - more like 1/6-1/4 hp.

    If you need 8 hours of pool pump operation per day (I'm a bit skeptical of that figure) there might be a way to run the pool pump only when the geo runs. There would be an issue of guaranteeing minimum pool pump run times during times of low geo system use such as in spring and fall.
  10. jennyleis

    jennyleis New Member

    A swimming pool heat exchanger could be so great for winter. Maybe I just need it some better reason to use it in my pool.

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