Just like another user posted here I am facing the choice of forced air vs radiant heating. I have two concerns. The first is the whole stale air issue. I'm planning a timber frame with SIF panels so the house is going to be very "tight". Glib answers such as "open a window" are not appreciated for those of us that suffer from allergies. The second issue is the whole subject of humidity control. Yes, humidity sensing fans in the normal places (bathrooms, laundry) might work but would leave a definite imbalance in the overall household humidity. And lastly, I have been searching and have yet to find any information concerning the sucessful application of radiant cooling. Any URLs or other directions would be appreaciated.

On the issue of stale air humidity control and alergies. Look at Nutech (Lifebreath) or related companies that manufacture Heat recovery ventilators. The HRV will control an over humidity situation in the winter and provide fresh air. On the alergy side use a Turbulent Flow Precipitator or TFP. It is a fabulous air filtration system that produces no Ozone. I must disclose I represent this company as well as Watts Radiant that can help you with your radiant cooling questions. Radiant Cooling is potentially tricky and in may cases will need to be suplimented. However, with a HRV in place you can use that air stream to help deliver cool air with reduced humidity durring cooling modes. If you want specific product information or more direct assistance feel free to contact myself, Nutech and / or Watts Radiant.

Steve

If you are worried about allergies and dust, then stay away from forced hot air!! As you know, radiant heating systems do not dry out the air like forced hot air systems. You may need some sort of ventilation system to prevent air stagnation but because of your air-tight home and not because of the radiant heating system.
Most radiant cooling systems are not designed or capable of acting as air conditioning systems. My advice to you; if you need air conditioning, put in an air-conditioning system.

You might want to consider a ground source coupled heat pump for your solution, with radiant heating and either fancoils or an airhandler for either full or partial air conditioning.

I have had such a system in my home for about 5 years now and it has worked very well. Because of the system design, our heating costs work out at the equivalent of oil at 40 cents per gallon or propane at 35 cents per gallon. We also get some 75% of our domestic hot water in winter for "free" as a byproduct from the desuperheater in the heat pump. See: http://www.northeastgeo.com/logan.html for background, if you are interested.

we've done radiant cooling a few times...the tube spacing is less than heating, and dewpoint/slab sensors are used to prevent condensation

-radiant cooling works best if there is plenty of direct solar gain in the room

...also, we've never found a single controller that will handle heating & cooling, we use a tekmar for heating, and moodulating valves for cooling

hi there

J I am about to install my first radiant cooling project and I have a bunch of question
-how did you cool the water (or whatever you used in your system) people always use the term "chillers" but haven't found any product which was designed for residential water chilling
-does the dew point sensor controls the dehumidifier or the pump?

thank you