Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Radiant cooling

Wayco Wayne_2
Wayco Wayne_2 Member Posts: 2,472
We have a nature center we take care of and the capacity of the A/C is marginal. It has high dome like ceilings with stuffed ducks hanging from strings as is they are flying. There is a big long picture window with a  view of a lake, that lets in a lot of heat. By the end of the hot day with the unit running non stop we can be as high as 82 degrees. Not the end of the world but not great either. We could find a place for a mini split I suppose, but with the windows wrapping around most of the room our options are limited. We have two Poly Ethelene pipes left over from a previous ground source heat pump whose loop is in the lake. The previous People didnt know how to work on it and were  askeered of it so they upgraded to residential equipment. What a bunch of maroons. I was thinking of reusing the pipes with a water to water heat pump and find a way to do some radiant cooling. My problem is the distribution side. What could we use tht we could run cool water through to top off our cooling capacity. Use your creative brains Nothing is too outrageous at this point.  

Comments

  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,472
    I remember

    at one of the Solar Decathalons I went to, Colorado used copper tubing to make a decorative room divider that they ran chilled water through to get the radiant cooling. I remember asking them why there wasnt a drip pan in under. They said the humidity in Colrado was so low they didnt have to deal with it. I remember thinking, "well dont run it here in DC, cuz our humidity is seriously high."
  • SWEI
    SWEI Member Posts: 7,356
    Radiant cooling controls

    take dewpoint into account.  With proper design and control strategies, you can remove most of the sensible heat using radiant, leaving you freedom to optimize the MUA and latent loads.



    In the southwest, we can often skip dehumidification.  One afternoon last month we hit 95ºF with a dewpoint of 14ºF.  I've seen spreads over 20ºF bigger in Phoenix.
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,472
    Thanks SWEI

    I googled radiant cooling distribution and founds lots of different devices that might fit the bill. It would be nice to hear from someone with experience though. I might just go figure it out and do it. Then I'll be the one with experience.
  • icesailor
    icesailor Member Posts: 7,265
    edited July 2014
    Radiant Cooling:

    There's something odd about radiant cooling. I once saw something about radiant slab cooling on a slab at the Bangkok, Thailand airport. Thailand is about the most humid place in the world. The issue was controlling humidity in the building where people were constantly coming and going. And that the slab didn't become a sliding pond and passengers slip, sliding away. It wasn't mentioned in the article how they controlled the humidity. I guess if you read it, you were supposed to know how they dried it out.



    Worth looking in to or maybe ME can add to it.
  • icesailor
    icesailor Member Posts: 7,265
    Funky Link:

    That's some kind of funky PDF link. It loads 3 megs and stops.

    Can you send it again?
  • Mark Eatherton
    Mark Eatherton Member Posts: 5,839
    Best resource on the interweb...

    Is Robert Beans web site, www.healthyheating.com



    Typically, radiant cooling is set to handle the sensible loads only, and depending upon the actual loads, possibly not ALL of the sensible loads, but in most normal cases, can handle all of it. A typical installation requires tubing at 6" O.C.,and an approach fluid temperature of 55 to 70 degrees F.



    If the tubing is at a wider center (typical) then it will carry half as much as it would at 6" centers, but in your case it would still help offset the loads.



    The possibility of creating condensation using fluid temperatures greater than 55 degrees F are slim to none.



    Chris, the airport in Bangkok uses a DOAS (Direct Outside Air System) to control the HUGE transient latent loads and environmental humidity that they see in that environment. They use large surface area finned heat exchangers, along with super cold water to wring the humidity out of the air coming into the building.



    Radiant cooling is just like radiant cooling in that it affects the Mean Radiant Temperature. On the heating side, we use the "standing outside on a cool day in the sunshine" to give people an idea of how it affects us. On the cooling side, it is like "standing in a basement on a hot summer day". It "feels" cooler.



    Having ceiling fans with a floor is a good idea to break up the stratified air to avoid a muggy feeling.



    Radiant cooling is no longer a "theory", but instead is a p proven method of delivering excellent human comfort. Shedding as much load as possible in the first place using off shelf technology (reflective window coverings, operable screens to keep fenestration gains out, over hangs, etc) makes excellent sense, but radiant cooling is a possible option.



    Robert helped Uponor in the development of the programs they use for calculating its ability to cool.



    If you've never been to healthyheating.com, plan on spending some time there to educate yourself. Robert does a fantastic job.



    If you join the RPA, we can teach you all of these things :-)



    ME
    It's not so much a case of "You got what you paid for", as it is a matter of "You DIDN'T get what you DIDN'T pay for, and you're NOT going to get what you thought you were in the way of comfort". Borrowed from Heatboy.
  • icesailor
    icesailor Member Posts: 7,265
    Slip Sliding Away:

    ME,

    I understand the concept when I saw mention of the Bangkok airport. It wasn't a comprehensive article. It only mentioned the radiant cooling slab. Made perfect sense to me. It mentioned that they didn't have "conventional" artic air cooling, just the slab to do it. I understood that too. And in order to keep the floor slab from becoming a summer sidewalk on a foggy morning, how did they get rid of the humidity? That was the problem. Great big dehumidifiers placed up high would seem to be just the ticket. Warm, moist air coming in from the outside, and sweat off the humans, rises up as lighter air/heat when it comes in the doors. Rises up and gets sucked into the dehumidifier and spits out cool dry air which falls to the floor. The cooler air falls through the warmer air and the warmer air gives off heat and humidity which ends up back in the dehumidifier. The moisture never gets to the floor.

    Paddle fans can be a guys best friend with high ceilings.  I hate paddle fans. I don't like that constant wooshing over my head, and sometimes shadows if light. The smarter ones than I never put ventilation ducting in to suck hot air off the ceiling and return it to the floor. Where the warm air disburses across the bottom of the floor and rises up for circulation. Instead, they put in paddle fans because they are a cheap fix. They push some air partway down. Especially in the modern AC/Heat Combi systems where all the registers (supply & return) are on the floor so in cooling mode, the cold air supply runs right across the floor to the return.

    They must take a lot of water out of the air in that airport.
  • hot_rod
    hot_rod Member Posts: 16,347
    would that condensate

    water be the same a desalinated water. Able to be treated for drinking?
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • SWEI
    SWEI Member Posts: 7,356
    Uponor RCDM

    Direct link is a bit of a hairball.  Go here http://www.uponorpro.com/Technical-Support/Manuals.aspx then click on Radiant Manuals to expand the category.  Roughly midway down the list is "Radiant Cooling Design Manual (RCDM)"
  • Radiant Cooling

    I'm lounging in 73 degree radiant cooling comfort right now. The comfort is the equivalent of radiant heating. I remove humidity much in the same way conventional ac does, with a large fan coil unit, but my fan coil and radiant surfaces are chilled only using well water. No mold, no condensation, just incredible comfort. The well water then goes out to water my garden, been doing this since 2000, it was as easy to do as it is Green, we should be doing this more, instead of making excuses about condensation.



    Thanks, Bob Gagnon LEED AP
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,472
    What about radiant cooling from above?

    I have an existing wood/ plywood sub floor floor. I was thing it might be better to hang panels up above for the cooling, or even wall panels.
  • Bob Gagnon plumbing and heating
    Bob Gagnon plumbing and heating Member Posts: 1,361
    edited July 2014
    That Would Work Wayne

    My ceilings and walls are heated/cooled with radiant, less thermal resistance than a wood floor, I built a large fan coil unit, out of 100' of baseboard element, that provides lots of cooling and dehumidification. This would give you the biggest bang for your buck. My bedroom is 68 degrees right now with just this fan coil running.



    Thanks, Bob Gagnon
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,472
    edited July 2014
    Bob

    You're a mad scientist and I love it. I have to remark though that that coil is butt ugly. To anyone but a plumber. :) I need something more pleasing to the eye since it will be in a parks nature center and open for view by the public. We have a domed cathedral ceiling with stuffed ducks hanging from strings. What could I hang up there to top off my cooling capacity?
  • icesailor
    icesailor Member Posts: 7,265
    Radiant Cooling:

    It would seem to me that if you used something that was along the lines of a fan coil cabinet set up for heat and AC, it has the condensate containment system and condensation wouldn't be a problem. If you used Radiant "Panels", condensation would form on the panels and then rain down on the stuffed dead ducks and living people.

    A chilled water/heat fan coil should work well. It isn't any different than installing a Mini-Split evaporator unit on a wall up high. And for cooling, that's where you want it.

    Or so it seems to me.

    Are there wells on site? Is the water OK and not need to be filtered? It might be possible to use groundwater as a source of cold water. You just need a place to get rid of the warmer used water.
  • Rich_49
    Rich_49 Member Posts: 2,692
    New

    Ultra Aire SD12
    You didn't get what you didn't pay for and it will never be what you thought it would .
    Langans Plumbing & Heating LLC
    732-751-1560
    Serving most of New Jersey, Eastern Pa .
    Consultation, Design & Installation anywhere
    Rich McGrath 732-581-3833
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,472
    Ice sailer

    I have a loop out running along the bottom of a 250 acre lake installed 25 years ago before the lake was filled in. I'm wondering if the water would be cool enough to use with a fan coil if not some kind of thermal distribution.
  • RobG
    RobG Member Posts: 1,850
    Geo Loop

    The only way to find out is to pump water through it and see. I would use a 50 gallon drum and circulate the water to see what temp you can maintain. There is no point in going further until you know what you are working with. They could have damaged the loop when filling in the pond. (and pressure test as well).



    Rob
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,472
    in my plans

    to do just that. I was thinking of putting an fan coil right in the exhibit area and put a sign on it. Sustainable Air Conditioning. Uses Lake water to cool. We'll have to prove the temp first. It use to support 9 tons of geo. I'll have to prove it viable and temperature worthy first.
  • RobG
    RobG Member Posts: 1,850
    edited July 2014
    Back fill

    Did they really back fill a 250 acre lake? That doesn't sound like much of a nature preserve :)

     How deep and how long is the loop and what kind of tubing and size?



    Rob
  • Wayco Wayne_2
    Wayco Wayne_2 Member Posts: 2,472
    Sorry

    I wasn't clear. It's a man made lake. They filled it with water 25 years ago. Before they did they ran a big long tube which is now at the bottom of the lake. The deepest part of the lake is 60 feet deep.
  • James Day_2
    James Day_2 Member Posts: 191
    radiant cooling

    I'm in the process of finishing up a radiant cooling system in my house right now. We are using geothermal as the source. Tekmar 406 house control to control the radiant cooling. Should be finished in about 2 weeks.
  • RobG
    RobG Member Posts: 1,850
    James

    Can you start a new thread on your system when it's complete and let us know how it works out? Pics would be great as well.



    Thanks,

    Rob
  • Bob Gagnon plumbing and heating
    Bob Gagnon plumbing and heating Member Posts: 1,361
    edited July 2014
    Radiant Cooling

    Fishing the last couple of days, no time to respond, we caught an 8' shark yesterday. Wayne, the fan coil is ugly but I put mine in a closet and just have a finished grate on the sheetrock wall you can see, and the water I pump out of the ground is 56 degrees, to give you something to go by on the Lake Project. My well is only a point driven well, I don't filter the water, but I run it through a heat exchanger to protect my heating system from the corrosion of all the ground water pumping through it. After the ground water cools my house, the water goes out to a 12 zone sprinkler system. Ice Sailor, I have a drip pan under the fan coil, and this removes enough humidity to lower the dew-point in my house, enough so the radiant floors, walls, and ceilings don't sweat.I tried cooling just my floor radiant first and they did sweat without a fan coil to remove humidity.  This is no big deal where I live because we only use our cooing a couple of weeks a year, but further south where cooling costs are much higher, it could be a really big deal.



    Thanks, Bob Gagnon
    To learn more about this professional, click here to visit their ad in Find A Contractor.
  • RobG
    RobG Member Posts: 1,850
    Well

    Bob, I understand that you are in NH so your cooling needs are allot lighter than mine in VA. How much water does that system use? You must have the greenest lawn in town. Is there a reason why you don't just dump it back in the well? with the cooling needs in my area my well would run dry in a matter of days.



    Rob
  • Harvey Ramer
    Harvey Ramer Member Posts: 2,221
    Rich

    That looks like a solution. IAQ in one neat package for Radiant Cooling and heating.

    Do you know anything about the manufacturer? Are they building their own stuff or is this a labeled product?



    Harvey
  • I'm in Northern Massachusetts

    Close to NH Rob G., I use about ten gallons a minute to cool my house, and yes the lawn is greener than ever. I water and run my Radiant Cooling only 2 or 3 weeks a year, and that's the only time I water. But I water deep, for hours at a time, encouraging deep root growth and the trees, gardens, and lawn seem to love it. We have a high water table here with unlimited water, but you could use a closed loop system, circulating water through a system of pipes underneath the ground, that would pick up the cooler temps, without pumping any actual water. It costs less in electricity to circulate water through a closed system, compared to pumping, like I do, but you don't get the water. I built my house in the late 80', with 2X4 construction and no air sealing, so you can expect a newer, better insulated home to perform even better.



    Thanks, Bob Gagnon
    To learn more about this professional, click here to visit their ad in Find A Contractor.