Hydronic Radiant Cooling & Heating

[gerrha]

Hello Everyone,
I am new to your forum and have a general question about hydronic radiant heating and cooling from ceiling panels. I am designing our new house, which will be in Oregon, and love the thought of radiant, but I do not think it will be that compatible with our flooring choices, wood, cork, and carpet. Now, I see that it might be possible to both heat and cool from hydronic ceiling panels. Assuming that you are able to maintain tight monitoring/control of the dewpoint for cooling, are these systems really effective when compared to in-floor radiant or even forced air?
Thanks

[johnsp]

I don't see the logic in hydronic cooling for residential use. While it might cool a space, how do you handle high humidity? Also the cost of a chiller system is much higher. In large buildings it's still done with heat exchangers (evaporators) with blowers just like a standard AC system. Radiant flooring is still best on tiles floors and thin engineered wood flooring. Cork is an insulator and would make radiant heating tough. Go with a hybrid system: radiant floor under hardwoods and tile, panel rads where carpeting and cork is used. A standard split AC system for cooling.

[RBean]

All floor coverings make great radiators as long as they are not highly polished ie: mirror like surface.

This is a function of the materials emissivity.

The combined R value of the floor including the coverings influences the required tube spacing and operating temperatures to deliver the design surface temperature but all typical floor covering operating at the same surface temps will have simliar emittance values.

The surface temperature of the floor covering is determined directly from the sensible cooling and heating load.

As far as the hardwood floor you can download a free copy of our guide to hardwood floors and radiant systems http://www.healthyheating.com - head over to the solutions page.

Radiant cooling can only take care of the sensible load ie: solar gains, lighting, heat from fridge/freezer compressor,dryers, ovens etc...The latent load from cooking, showering, and humidity in the air can only be properly addressed with an air system. Depending on your location and building efficiency it’s possible the latent load can be handled in the ventilation system leaving the radiant system to handle the sensible loads. Lots of energy saving and comfort benefits to this type of hybrid system depending on your project.




[Edited by RBean on 04-22-2005 at 11:04 AM]

[millerman]

Where in Oregon? I'm in Eugene.

[gerrha]

Thanks for the responses everyone.

The house will be in Corvallis so my climate will the same as yours Millerman, but I am a Beaver fan!

If a complete hydronic heating and cooling solution was feasible, it seems to me that humidity control for a house, especially in our rather mild Oregon climate, could be achieved through the ventilation system.

However, it now looks like hydronic cooling is not yet a mainstream product - at least in residential applications. Therefore, correct me if I am wrong, but it also seems a bit hard to justify having hydronic heat, and in fact hydronic heat with many modifications to work with different flooring types, plus a complete forced air cooling system.

Maybe we are better off with a ground-loop geothermal heat pump forced air system with lots of IAQ equipment?

Thanks again.

[johnsp]

I suppose your heating season is at least 6 months and the need for AC is probably 2 months? I would invest in the most comfort for the system I used the most. Ceiling based AC supply is the best for cooling, worst for heating. So go with 2 systems.