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Thread: DIY Heater tuning/setup

  1. Back To Top    #1

    DIY Heater tuning/setup

    Aloha all, I have a few odd problems with my DIY setup as described below: I am using a 1/8 hp pool pump for my 7800 gallon pool so I get very little or no pressure on the filter gauge, so it is hard to figure out how much water to divert to the solar heater. If I adjust much under 4 gpm I seem to get a lot of air burps every 10 seconds or so. I think it is that air is sucking back from the 2" return line to the pool. Am I asking too much from a 1/8 hp pump? The flow is really good going 8' up to the "panels" on the roof. (actually no degradation in water volume). It was sunny for 1/3 and overcast for 2/3 of today and the water was running at 6gpm to the panels (and 6gpm to the pool from filter) ranging from +1 degrees to +4 degrees depending if the sun was out. I raised the pool 3 degrees. Pool is covered with a white tarp roof and the most the ambient daily heat raised the temp before was 1-2 degrees, so I feel the heater boosted the temp by a solid 1 degree.

    Questions/Comments

    I put a valve on the return line to throttle down the flow a bit and it seems to help the water/air burps.

    I am going to install an air relief port on both of the 2" headers (and elevate the headers on that end by an inch or so) as I think maybe air is getting trapped and the pump does not have enough "push" to expel the air. And some of the 33 tubes are hotter than others. Maybe some are running dry?

    Anyone here had experience with this tuning phase?

    thanks
    Francis

    Here is the heater setup
    1: used 2 x 2" headers and 33 1/2" x 45' tubes
    2: NO LEAKS !!!
    3: I used a hole saw and drill press to drill out the 66 holes
    4: Used a 1/2"x1/2" joiner coupling that I turned down on my lathe to tightly fit the 66 holes made above
    5: Bought irrigation 1/2" compression fittings that glued into the couplings @ .22 each

    Total cost about $150.00 parts

    Labor intensive and probably not as good as the Ebay panels (2 x 4x20' ones are coming tomorrow so will be able to A/B test the effeciency. So better idea to buy store bought panels unless $ is a real issue.
    I can adjust from 6gpm @ 2 degrees to 2gpm @ 6 degrees.
    7800 Gal. 8' wide x 20' long x 7' deep
    Hayward 1200 Cartridge 7200 GPH, Waterworks 1/8 hp 2400 GPH
    Made from 20 Container Lined with "PolyUrea/Rhino Lining"
    Workshop, welding etc,+office+living area running off grid on 10kw PV

  2. Back To Top    #2
    launboy's Avatar
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    Jun 2008
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    Re: DIY Heater tuning/setup

    How many GPM does your pump put out total? I'd imagine with a smaller pump like that, and all those parallel coils, you should be able to divert the full flow through the panels.

    The air bubbles are to be expected as the water fills the tubes and empties them of air. These should go away after a while. Also, all the panels should be about the same temp.(can you take a pic. of all of the panels mounted???) If some are mounted higher then others or have longer runs to the maifold, I'd expect those to be slightly warmer due to less water flow(possibly) but if there are say, three panels on the same level, with similar lengths of pipe to the manifold, one shouldn't be warmer than the other two.

    HTH,
    Adam
    18' x 42" Intex Easyset Pool, with 16' x 52" deep end in the middle. Approx. 5500 Gal.
    Hayward Power-Flo LX 1 HP, 100# Jacuzzi Brand Sand Filter(Piped underground so it looks nice) 8)
    3 - 2' x 20' Solar Pool Heater Panels(roof mounted)
    Goin' on 9 summers...NOBODY thought it would last this long.
    Buried Portable Spa sharing pumps and water with pool (Almost complete project)

  3. Back To Top    #3

    Re: DIY Heater test results

    Aloha, pump puts out 24 GPM, but I have measured 18 gpm after filter and after lifting the water from the 8' depth. After lifting another 8" to the panels I can get up to 15 gpm through the heater discharge.
    Yes, I think all the water will go through the panels. I installed an air drain petcock on both the inlet and discharge header and raised the headers 4" on one end. That did the trick to purge the air.
    Since the pump is so small I need to give a little back pressure so it does not suck air back up through the heater 2" discharge into the header.
    Right now I have 79.5 pool temp and 83.4 heater discharge @ 10gpm. Will see if I can go to 12gpm without sucking air back. Nope, 10 gpm is the max before air migrates back up into the discharge header and at 10gpm I am seeing 6# pressure at the filter.

    SATURDAY TEST RESULTS mostly overcast

    09:30 am Pool 79.5..........1/2 sun
    10:30 am Pool 79.7..........no sun outlet is 2.0 degrees hotter than pool @ 10gpm
    11:30 am Pool 79.9..........no sun
    12:30 Pm Pool 80.1..........1/2 sun
    1:30 pm Pool 80.2..........no sun
    2:30 pm Pool 80.4..........1/2 sun
    3:30 pm Pool 80.8..........3/4 sun outlet is 3.6 degrees hotter than pool @ 10gpm
    4:30 pm Pool 81.0..........full sun but weakening, sets at 7pm
    6:00 pm Pool 81.1..........thats all. Pool settled at 81.0 and heater dropping to 81.0 too.
    One hour before sunset the solar energy is about nil.

    SUNDAY TEST RESULTS Mostly sunny
    7:30 am Pool 79.5...........sunny (back to where I started yesterday!)
    9:30 am Pool 79.7...........1/2 sunny Heater @ 82.8 @ 10gpm
    11:30 am Pool 80.0...........sunny
    3:30 pm Pool 81.1...........sunny

    MONDAY
    leaving solar heater off today to try figure out how much temp is increased by ambient and determine if the water temp drops 1.6 degrees from whatever it ends up today until tomorrow morning as it has been doing the last 2 days
    7:30 am Pool 79.5
    1:00 pm Pool 79.5 Although ambient is 87.5 and 15mph breeze, and you see I have a "chuckwagon cover" so sun does not hit the pool, temp is not rising much
    2:30 pm Pool 79.9
    4:30 pm Pool 80.1
    6:30 pm Pool 79.9 We will see if it drops 1.6 degrees to 78.3 overnight

    TUESDAY
    Solar will be off. Taking the "Chuckwagon" cover off the pool to see how much the direct sun heats.
    1/2 sunny
    8:00 am 78.4 Dropped the 1.5 degrees overnight
    4:00 pm 80.8 sun direct most of the day, not using panels

    Wednesday
    Open top for direct sun, both solar panel systems up and running
    7:30 am 78.8 mostly sunny today
    12 noon 81.5 solar running 35 gpm @ 2.9 degrees solar heat increase, mostly sunny.
    3:00 pm 84.2 high clouds
    5:00 pm 84.8 mix sun and clouds TOTAL WATER temp gain today 6 degrees

    francis

    Here is a link to see the system
    http://i431.photobucket.com/albums/qq39 ... age244.jpg
    http://i431.photobucket.com/albums/qq39 ... age242.jpg
    7800 Gal. 8' wide x 20' long x 7' deep
    Hayward 1200 Cartridge 7200 GPH, Waterworks 1/8 hp 2400 GPH
    Made from 20 Container Lined with "PolyUrea/Rhino Lining"
    Workshop, welding etc,+office+living area running off grid on 10kw PV

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