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Thread: Indoor Pool - What should be considered?

  1. Back To Top    #1
    stever's Avatar
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    Indoor Pool - What should be considered?

    Hello,

    My father is wanting to build an indoor pool -- their house is in a very windy area, etc. It'll keep the pool cleaner and used more year-round as well. He'll have solar (of course) for at leeat 100% of the pool area.

    What are the concerns with an indoor pool? Can anybody help with the following (or other issues):

    1) how much venting is needed to keep windows from fogging up/mold & mildew?

    2) what materials should be used and avoided for the construction of the pool-house? He is looking to build a traditional 'house' around the pool (or rather a pool within a house) -- no a pre-fab metal enclosure. Can the walls be paperless drywall with a plaster finish?

    3) what particular chemical balance issues are there?

    4) How much less evaporation/heat loss is there? Will solar be enough to heat (little or no direct sun) the pool alone?


    Thanks!

    ps. the county is making him put fire-sprinklers in the ceiling over the pool..... ***?
    Pool: 625 SF Free-Form In-Ground Shotcrete Pool w/7.5' dia spa.(8 jets), 24" raised bond beam (22,500 gal)
    Pentair Equip: Intelliflo VF Pump, MasterTemp 400 Heater, IC40 SWG, Quad DE 100 Filter
    Automation: IntelliTouch i7+3 (+ extender panel), 6 Jandy Automated Valves (S, R, Spa Bypass, Solar, Cleaner, Spillway)
    Other: 75% Solar, Kreepy Kruiser Cleaner, Tan Hip-Hop Diving Board (a bit curved) on 606 Cantilever Base (SR Smith)
    Links: [TFP Pool Build Thread] - [TFP Landscaping Thread]

  2. Back To Top    #2
    JasonLion's Avatar
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    You really need a professional indoor pool designer to develop the plans for you. Indoor pools are more complex to deal with than outdoor pools. You need massive amounts of ventilation and depending on planned usage you may need massive amounts of dehumidification. Without the dehumidification the air above the pool will tend towards 100% humidity. It is possible to build a room that can survive that but it requires special materials and is generally difficult to do and it isn't all that pleasant to be in. No way do you want that 100% humidity air getting into your living space if the two are connected.

    The pool chemistry gets a little more complicated as well, since CC tends to buildup without sunlight to help get rid of it. There are various strategies to combat that, MPS, SWG, UV etc. In general more attention is required.

    Heating is usually easier. The high humidity reduces evaporation, which is normally the primary cause of heat loss.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  3. Back To Top    #3
    stever's Avatar
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    Quote Originally Posted by JasonLion
    You really need a professional indoor pool designer to develop the plans for you. Indoor pools are more complex to deal with than outdoor pools. You need massive amounts of ventilation and depending on planned usage you may need massive amounts of dehumidification. Without the dehumidification the air above the pool will tend towards 100% humidity. It is possible to build a room that can survive that but it requires special materials and is generally difficult to do and it isn't all that pleasant to be in. No way do you want that 100% humidity air getting into your living space if the two are connected.

    The pool chemistry gets a little more complicated as well, since CC tends to buildup without sunlight to help get rid of it. There are various strategies to combat that, MPS, SWG, UV etc. In general more attention is required.

    Heating is usually easier. The high humidity reduces evaporation, which is normally the primary cause of heat loss.
    Thank you -- it is a seperate structure that wil have a garage and a party room -- but it would still not want to be 100% humid. There is a constant west wind and he'll have windows at the west (and other sides for exit) to keep the air turned around. Of course the more circulation the lower humidity the more evaporation.... I'd ask what the ideal % would be, but there would be no way to achieve it!

    He plans on SWG -- but I'll bet CC can still build up. Less CYA needed I'd bet....

    Steve
    Pool: 625 SF Free-Form In-Ground Shotcrete Pool w/7.5' dia spa.(8 jets), 24" raised bond beam (22,500 gal)
    Pentair Equip: Intelliflo VF Pump, MasterTemp 400 Heater, IC40 SWG, Quad DE 100 Filter
    Automation: IntelliTouch i7+3 (+ extender panel), 6 Jandy Automated Valves (S, R, Spa Bypass, Solar, Cleaner, Spillway)
    Other: 75% Solar, Kreepy Kruiser Cleaner, Tan Hip-Hop Diving Board (a bit curved) on 606 Cantilever Base (SR Smith)
    Links: [TFP Pool Build Thread] - [TFP Landscaping Thread]

  4. Back To Top    #4
    JasonLion's Avatar
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    The big issue with a SWG on an indoor pool is to keep a close eye on the FC level and adjust the percentage as needed regularly. With outdoor pools the FC level is somewhat self regulating. Higher FC levels mean more FC lost to sunlight, so the percentage setting doesn't need to be precise. In an indoor pool the FC lasts longer and setting the percentage too high can drive the FC level up more or less without limit. Thus the percentage setting becomes critical and will need to be adjusted frequently.

    Indoor pools are traditionally run without any CYA. That makes monitoring the FC level even more critical, since it doesn't take that much FC to cause corrosion when CYA is zero. Chem Geek has been suggesting running indoor pools with CYA at 10 to 20. That is tricky to measure but otherwise has many advantages.

    The SWG will take care of some or all of the CC (super-chlorination inside the cell). However that isn't always enough. When CC persists despite the SWG you can add MPS regularly to prevent CC from forming in the first place or use a UV system to help destroy it. UV also wipes out some of the chlorine, something to take into account when figuring the cost of UV, and also helps make the SWG percentage less critical (since you are losing a percentage of the chlorine to the UV system, similar to sunlight for an outdoor pool). Chem Geek believes that CYA will help regulate CC formation, so MPS/UV may not be required with CYA.
    19K gal, vinyl, 1/2 HP WhisperFlo pump, 200 sqft cartridge filter, AutoPilot Digital SWG, Dolphin Dynamic cleaning robot
    Creator of PoolMath and Pool Calculator. Other handy links: Support this site, TF Test Kits, Pool School

  5. Back To Top    #5
    My indoor pool humidity is kept around 45% and never gets higher than 70%max. In the winter it does go lower but that's OK.

    My pool is inside my house and my house is built no different than any other house. I did choose myself to use an epoxy paint in the room since my kids splash everywhere.

    Using special materials for an indoor pool area (residential) is the wrong way to approach things. You must control the humidity and ventilation.
    The room should be handled with a combination of circulating dehumidifier(s) and constant negative pressure ventilation.
    The ventilation should be constant and negative(exhaust) pressure. This ventilation keeps moisture from penetrating the structure and keeps the concentration of corrosive chemicals to a minimum.

    If possible it is a good idea to install an automatic cover for the pool durring construction. They can be totally hidden under the floor. First off I have 2 kids and the safety factor is priceless. Secondly, while the cover is on the pool, I've never had my dehumidifier come on thus saving me a ton of $ on electricity.

    Keeping the air temp in the room atleast 2deg warmer than the pool water also keeps humidity/evaporation to a minimum.

    Another nice feature I did was to install radiant heat in the floor around the pool. There is nothing worse than cold concrete on your feet while relaxing around the pool.

    As for your chemical ?'s you can search for my post on the problems I had with that issue. Bottom line, while using SWCG I couldn't get my CC down along with the salt causing damage. Only thing I can figure out that wasn't ever cleared up was my phosphate levels were way high and that may have been the problem with not being able to get the CC down. Since I've switched to regular water and just add liquid chlorine I've been able to keep my reading perfect and keep CC to 0-.1

    If you have any specific indoor pool questions I most likely may be able to answer them.
    21,000 gal Fiberglass (Indoor)

  6. Back To Top    #6
    stever's Avatar
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    Thank you -- good information.

    As he gets closer to doing this, I'll probably have a few more questions. He is planning (for now at least) to use SWG as his eyes are very sensitive to chlorine (as are mine) -- but it's got to work. The negative pressure is nice to know. He'll have a fair amount of positive pressure with openings to allow the air to get out, but this might not do the job...

    The radiant heater is a great idea! Is your electric or circulating water? I'm afraid in So. California that either way would not be cheap.

    Thanks for the advice,

    Steve
    Pool: 625 SF Free-Form In-Ground Shotcrete Pool w/7.5' dia spa.(8 jets), 24" raised bond beam (22,500 gal)
    Pentair Equip: Intelliflo VF Pump, MasterTemp 400 Heater, IC40 SWG, Quad DE 100 Filter
    Automation: IntelliTouch i7+3 (+ extender panel), 6 Jandy Automated Valves (S, R, Spa Bypass, Solar, Cleaner, Spillway)
    Other: 75% Solar, Kreepy Kruiser Cleaner, Tan Hip-Hop Diving Board (a bit curved) on 606 Cantilever Base (SR Smith)
    Links: [TFP Pool Build Thread] - [TFP Landscaping Thread]

  7. Back To Top    #7
    SWG is still chlorine. My heat is hydronic(water). It uses a gas fired boiler which could also be used to heat the pool water using a heat exchanger but I chose to keep them separate and heat my pool with a regular pool heater.
    21,000 gal Fiberglass (Indoor)

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