RADIANT COOLING Condensation is the enemy of radiant cooling.
COOL RUNNINGS Condensation is the radiant cooling killer, but it can be overcome with proper controls. BY CURTIS BENNETT
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MH28
FALL 2023
MODERN HYDRONICS
something I used to say about myself—a different type of ‘cool,’ LOL. Now, why is there not a lot more radiant cooling used in homes and buildings. I believe the reason is installation. You can radiant cool in the floor, but to get the convection moving a lot the cold needs to “fall” down , the exact opposite of heat rising. When you use radiant heating in a floor, it does two things, it radiates heat, obviously, but it also starts some convection due to thermodynamics, heat rising. Not a lot of convection like a furnace blower or fancoil moving air, this is natural convection. The problem with radiant cooling only in the floor is that cold air falls, if it’s already at the floor level the air has nowhere to fall to create convection. To get good cooling convection you need the radiator to be in the ceiling. So, this creates a new set of installation issues. Now don’t get me wrong, I understand that radiation works and works well in providing comfort in a building. That is the main function of radiant cooling and heating. I am just saying that creating convection helps with the effect. WWW.HPACMAG.COM
PHOTO: BLAKEDAVID TAYLOR/GETTY IMAGES
ell, it seems it’s happened again. I electrocuted myself just a little. How can you electrocute yourself a little bit? Well, I needed to put in a new ceiling fan, as the old one had a small tick, tick , tick and it was very annoying trying to fall asleep. Anyways, I purchased a new fan and was going to take out the old one and thought, the fan is off so there is no power going to it. There is no switch for it, it has a wireless control, so that is why I proceeded to start disconnecting it after taking it out of the ceiling. I think you can see where this is going. Taking the marrettes (wire connectors) off and proceeding to touch the wires— that I thought were not live, of course they were. Luckily, I have one common practice
when doing electrical work; I don’t grip any wires hard. I know that sounds stupid, but the more pressure you put on the wire the more contact it makes and the bigger the path it has to conduct with your body. So, because of this practice of mine, I just got a little bump. Enough to make me squeal and my family knew exactly what happened. I electrocuted myself … again. Now although I do make light of these situations, they are serious. I hope in my thoughtlessness you can learn a couple things to remember when working with electricity. Ok so now to the topic at hand: cooling, specifically in-floor or radiant cooling. I touched on this topic about a year ago in the pages of HPAC, and I just wanted to talk more about the subject. Radiant cooling has been around for a long time. The physics are the same as radiant heating. Have you ever taken something frozen out of the freezer. Dumb question, of course you have, but when you take it out you can “feel” that it is cold even when you are not touching it. Well, that roast or ice cube or whatever it is, is radiating coolness. Sounds like