THERE INSTALLING RADIANT COOLING PANELS IN THE CEILING ,AKA CHILLED BEAMS ,IN A 7 STORIE HIGH RISES WERE I WORK. IVE SEEN SOME ENGINEERING DATA ABOUT THE PANELS, 60 DEGREES WATER,= X # BTU REMOVED . NEW AHU'S TO HELP CONTROL HUMIDITY. I' VE READ THAT THE PANELS WORK WELL IN EUROPE FOR YEARS?
NOW WHAT THE REAL STORY? WHAT TROUBLE SHOULD I EXPECT? OR IS IT ALL GOOD & GREEN, LEED!
All I can think of is the possibility of condensation forming on the panels. So if they are 7 stories up, it will really be like its raining. Liebert uses a chilled liquid refrigerant system to handle the high density heat loads in computer rooms. The difference is that in the server rooms is that the server room is designed to be maintained to +/- 5% of the RH setpoint . I can't imagine that an AHU can maintain the RH without being designed for the worst case senerio. You know that won't happen as value engineering always reduces the capacity for the 90% instead.
The Dew point is kept well below the temperature of the panels. The rejected condensor heat dries the Dessicant, that is pulling the humidity out of the the make-up and recirculated air. Very efficent design with lower than traditional air conditioning humidity levels. Seen it in labs where they need good control over humidity, with low airflows.
works really well, serviced a building before with it and no problems just make sure set points are correct. Just like anything else. People in Europe are way ahead of the game compared to the US, sorry to say it. I was over there twice this year and I noticed most buildings used chillers and boilers, didn't seem like they used these crappy RTUs
most building with chilled beam use an air exchange unit, with a dessicant wheel, and a cooling coil to condition outside air prior to entering the occupied spaces. low dew points and high water temps work well. issues that need to be considered are chilled water control, and dewpoint control of the air. this is not a do it yourself project for sure. in all of the ones we have started, we have seen chilled water typically in the 45 degree range leaving the machine, and going to the coil in the air exchange unit, with 60 ish water in the chilled beam loop piping. this is accomplished using a three way mixing valve. the untis are typically active, using air supplied via the energy recovery or air exchange unit to the chilled beam. have seen no rain forests yet......
I've always wondered how these would work in someplace like D.C.
We keep hearing of chilled beams, both active and passive, and I know the HVAC engineers get real nervous when you ask about the extra dehumidification required, since you are running 60 degree supply to the "chilled beams".
I think you'd have problems in my area, let alone places where they have "real' humidity.
Last edited by Randy S.; 01-22-2010 at 09:09 PM.
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We did some in Dallas, Texas not long ago. I was pretty sceptical considering the high humidity levels down here. I figured these things would be like a rain forest. However they have been working well. We are monitoring space dewpoint and controlling the beam temp to 2 degrees above the space dewpoint. This allows the beam temp to float with the dewpoint.
maintaining rh sensors will be the real chore. the closer you get to "perfect" efficiency, the less tolerance you have for non-standard conditions...so keep that sensor accuracy up!
one of the advantages (disadvantage in my opinion) is less room between ceiling on one floor and the floor above it.
i have not personally seen one of these systems, however, after reading about them, they are somewhat complicated so get everyone in one room and don't let them leave until the whole thing works!
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Where at ?
Originally Posted by lwarren
It takes three people to do anything around here. Two do the work, one explains to the crowd of people who showed up when they seen smoke and flames.
The Wyly Performing Arts Theatre.
Originally Posted by thegoodlistener
Anyone ever use the version with a drain pan?
Called valence cooling:
I WAS ALSO INFORMED ,THE BUILDING WILL HAVE "JCI" CONTROLLES
I have seen this used very successfully. They run radiant heat through the floors and switch to chilled water through a valence in the summer. The humidity is very low in his part of the country so condensate isn't so much of an issue but what there is just drains away. His original plan was to run chilled water through the floors in the summer. That didn't seem like such a great idea.
Originally Posted by bbaumer
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