Geothermal radiant, AC and pool heating

Discussion in 'Geothermal Heat Pump Applications' started by Rick, Mar 22, 2012.

  1. Rick

    Rick New Member

    We are planning on building a recreation and entertainment building on our country property in central VA. It will have an indoor pool a great room and plenty of space. It will be built on a slab so it would seem to be natural to think about radiant heating. But we are in central VA so we will need air conditioning as well as dehumidification for the pool room.
    This past summer we had two split geo units installed in the 1925 house and so far we love it. I talked to HVAC contractor that installed that system to get some info about doing our pool building. I was asking about doing radiant heating and they said that the only way to have radiant would be to get the heat off the desuperheater when the air conditioning is running. Not exactly what I was hoping for.

    What I want to know can you have radiant heat and have air conditioning with one unit?
    If not one unit is it economical to have separate heating and cooling units? Could they share loops?
    Can you heat an indoor pool with a cover year around and if so who makes the pool heaters?

    We have plenty of land for the loop field so that is not a problem. The building is 4500 sq ft so if we can keep the heating and cooling reasonable without fossil fuels it would be great.
    Thanks for your help.
    Rick
     
  2. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Some replies

    What I want to know can you have radiant heat and have air conditioning with one unit?

    Hybrid units by Hydron, Waterfurnace, Climatemaster can do radiant hot water and hot/cold air with one unit

    If not one unit is it economical to have separate heating and cooling units? Could they share loops?

    You can do individual heat pumps tied in to one loop as well. Comes down to load matching. A hybrid unit may/may not be a good fit depending on the individual demands.

    Can you heat an indoor pool with a cover year around and if so who makes the pool heaters?
    Same companies as above (and others) can do pool heaters. BUT for an indoor pool you are heating a building - not the pool. Unless you want different temperatures in the building than the pool. Then things get complicated and expensive. Also dehumidification plays a strong roll.
     
  3. Rick

    Rick New Member

    Thanks for the information I will research to see who works with these manufactures in my area.
    We would want to heat the pool in addition to the room. I realize the upfront cost will be expensive because of the loop field addition but in the long term would it be more efficient then an air to water heat pump? The pool is about 10,000 gallons. I am willing to pay the upfront cost if it will pay for itself in the long term.
     
  4. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    Heat loss

    I should have been clearer. You, of course, will be heating the indoor pool, but the main heat loss then becomes the building - not the pool. But airflow across the pool is important (for breathing), dehumidification, etc. And if you now want the pool water at a different temperature than the pool room, it gets complicated.
     
  5. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    If you wanna feed the beast a wood boiler isn't a bad fit for this job......
    WTW geo might be your best fit because you will need very little cooling. Most times you keep the enclosure 2* warmer than the pool so not much AC is needed in a pool house.
    Storage tanks full of heated or chilled water can be used to heat pool, pool room, DHW and cool recroom in the summer virtually at the same time.....payback is another question you will need a good designer for.

    In a home with indoor pool, mycustomer used geo for heating and cooling the house and wood boiler for heating pool and pool house. Conventional AC cools when needed in summer.
     
  6. Rick

    Rick New Member

    Thanks for your ideas. Down here in VA we will definitely need AC and humidity control for the main part of the building. Last summer we had 37 days above 90 with humidity. Up your way probably not as hot. The pool room will need humidity control or we will have a rain forest. Has anyone used geo to heat a pool in a moderate climate. I have read about people using it down south. Is the biggest drawback of using it for the pool having to have a much larger loop field and slow response time?
    What would one look up to find someone to design a HVAC system that included geo? I was not impressed with the local HVAC installers plan.
    Thanks again.
     
  7. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    Nearly all pool heating load arises from sensible and latent loss from the pool's surface to the air above.

    Having the pool indoors changes everything.

    In theory you could use waste heat from dehumidifying the pool house air to heat the water, but of course that just drives more water into the air.

    You may want to hunt down a frequent poster here or at GreenBuildingTalk - "Brock" from Wisconsin. He has an indoor pool and geo.

    Since you are in VA and presumably want to use the pool year round you may want to consider insulating the walls of the pool itself.

    If the pool walls are insulated and the pool house reasonably tight, maintaining pool temperature should require fairly low capacity once the water is up to temperature.
     
  8. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Ha ha ha.

    Do not forget about dehumidification. You will need heating and cooling year round.

    I bid the HVAC service contract for a city with an indoor pool and an indoor ice rink. I lost the bid to a major national player because no one saw the heat transfer. They paid to heat the pool and building. They paid to cool the ice rink and building. They just transferred the heat and cool away.

    Very sad.

    Mark
     
  9. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    I missed

    Radiant cooling.

    My bad.

    I do stuff like you are looking for all the time.

    Radiant cooling is possible with proper attention paid to dew point. The rest can be done with air handlers.

    I think that you can dig up a bunch of land is a plus, but what I see is a big heat sink called a swimming pool.

    I am a "wet head" so my favorite way to move heat is with water.

    Do you have drawings?
     
  10. Rick

    Rick New Member

    Mark and Curt
    Here are some plans for you to look at. We plan to insulate the footings at the perimeter of the building and the pool will have a cover on the pool most of the time to reduce the heat loss.
    You say in theory you could use the waste heat from dehumidification to add heat to the pool. Is this something to really think about or just an idea. I am willing to think outside of the box and consider anything beside just a basic water to air system. So far I am sold with the system in the main house after this winter although it was not that cold this year.

    Radiant cooling. Is it possible in a humid climate? I can just imagine coming in one day that we missed on the dew point and having dripping wet floors.
    You will say after seeing the pictures that this looks like a barn. Well it is. It is what we have to work with since because of where we are it is very difficult to build new. Long story. We will insulate and plug all the holes and make it like new.
    Rick
     

    Attached Files:

  11. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    Rick

    You have mail.
     
    Last edited: Mar 26, 2012
  12. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    If you have a closed loop geo system, ground loops would cool while heating the pool and warm while cooling/dehumidifying the enclosure. With storage a water to water could do both simultaneously (heat pool with water in a storage tank while cooling through a DX fan coil or with chilled water stored in another tank) once cooling set point is met, the storage tank can be brought back up to temp. This scenario is very efficient though may require back-up boiler or significantly more ground loop for winter.


    Radiant cooling is possible anywhere, the question is whether it is a good fit anywhere. Because you already need to move air for dehumi, forced air cooling seems like a better fit.

    My aforementioned client had natural gas available so geo did not have a terrific ROI, but if your faced with propane, oil or resistance electric, geo may be worth it. Make sure you don't take tax credit for granted without a heart to heart with your accountant.
     
  13. Rick

    Rick New Member

    Thanks

    Everyone has given me much to look into. I appreciate your help. When I get more questions I will be sure to come back to you all. As I move forward with this project I will let you know how we are doing.
    Rick
     

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