Why aren’t chilled ceiling tiles/panels used to cool rooms in North America?
In the Henry Gifford interview, he said “You should add or remove heat by moving water or refrigerant only, not by moving air around.” This reminded me of articles I had read about European HVAC systems that use chilled ceiling panels to cool rooms and have separate dehumidification systems. This sounds like a very efficient approach – especially in hot humid environments. Why don’t you hear more about this sort of system in the US?
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What about condensation on these panels ??
i thought it was not really possible to cool with radiant because of condensation issue in high humidity summer temps ???
Scott,
The ceiling panels will drip with condensation unless the building has very good control of indoor humidity levels. In a hot humid climate (anywhere from Texas to Florida, and north of there), that means that you need a whole-building dehumidifier. Since the dehumidifer is expensive to install and operate, you might as well just install an air conditioner.
There are parts of the US where radiant cooling can work without mechanical dehumidification, but for most of the US the outdoor dew-points are way too high during the cooling season. Most of Europe has much drier summertime air, and lower cooling loads (both sensible & latent) than most of the US.
Where radiant slabs can be used for cooling in the US, adequately insulating the chilled water plumbing to avoid points of condensation is an issue. Insulating the pipes is fairly straightforward, the problem areas tend to be at the manifolds.
Thanks for the insights - that was helpful