radiant heating ?

[ozley]

The ceiling heat would give me a headache. I had to wear a hat when working in apt. that had it.
Back before the panels the the guys installing it just ran a wire back and forth then they would but a skim coat of plaster over it. Well they would write words and after a time they would show up on the ceiling.

 

[Raspy]

Beez,

Except that we usually have clothes on, which reduces the radiant loss from our bodies, and the fact that we conduct heat from the warm floor with our feet directly, not through radiation.

It's all a matter of difference in radiation rates and temperatures.

It's not fair to say we "can't" be warm if the walls are "cold". Define those temps first. But it is true that we can feel comfortable in a cool room within certain parameters. Those parameters are what we use for reference in programming the thermostats and designing the temperatures. At what point does a warm floor compensate for a cool wall, etc., and can we use that info to get comfortable without heating the entire space.

Here is an important point: It is NOT important to keep the walls at a temperature as close to our bodies as possible, in order to be comfortable. Not true. 70-75 degrees is much closer to a realistic max for general living areas. If the floor gets to 87 degrees in a well insulated and stable room, where the walls are close to that but a bit less, people can't stay there for very long without overheating. If the temp needed to be equal with our bodies, we'd be most comfortable in a place with 100% humidity and 98.6 degree temperature. Sitting around in that kind of heat is oppressive and trying to sleep in it is very uncomfortable. See what I mean?

The reason it's important to find that comfortable situation is that it is much more efficient and even more comfortable than just heating until the thermostat says 70 degrees or whatever. It prevents overheating later, overshooting and heating when no one is home etc.

Unlike with forced air, we have to anticipate and time the system a bit to get the maximum comfort. But at least we don't have to put up with the draft, the noise and the mixing of all the air in the house as we do with forced air.

 

[V1Rotate]

I like my hot water baseboard radiators. They are located around the perimeter of the outside walls so the warm air that they produce warms the walls above them. Also, they are not noisy or drafty.

 

[KubotainNH]

I've lived in all of them, current house is hot water radiant in the floor which is the best so far. My only complaint is slow to heat up. Next is hot water & electric baseboard. After that it all sux. Radiant in the ceiling was awful and forced hot air blows too. FHA is dry, dusty and only comfy at the midpoint temp. Wood heat is way too dry. Haven't lived with a pellet stove but seems to be a good way to make a room comfy.

 

[BeezFun]

Beez,

Except that we usually have clothes on, which reduces the radiant loss from our bodies, and the fact that we conduct heat from the warm floor with our feet directly, not through radiation.

Rule of thumb for HVAC design is a resting human (with clothes) produces 400 BTU/hr. Of that, about 100 is through evaporation (perspiring and breathing), 100 is through conduction/convection, and 200 is through radiation. I didn't expect that the walls would be kept at a temp above the room temp, but the body is very sensitive to the difference between a 40deg wall and a 70deg wall. It's not uncommon in old homes to see frost in the corners, very common to see frost on windows even in new homes. That means the temp there is 32deg or colder, which has a big effect on comfort. So you can install any kind of heat you want, but if you don't build the place well enough to keep the envelope warm, grandma is going to turn up the thermostat.

In the summer the wall temp is probably in the 80s on a hot day, which is so close to your body temp that radiation is no longer significant in your comfort level. Instead evaporation dominates the heat exchange and if the AC isn't designed to remove the moisture, you'll feel hot.

 

[PAGUY]

Ok guys, with this being a bi-level would it make sense to keep the downstairs (family room) temperature setting higher than the upstairs (parlor) as the ceiling radiant heat downstairs should effect the flooring upstairs? I'm thinking it has to be a matter of controling temp settings to find comfort level in occupied rooms.

 

[Raspy]

Paguy,

You'll probably find you don't need to run the upstairs heat at all and the downstairs ceiling radiant might make the upstairs floor pleasantly warm.

Since warm air rises, and unless you have some sort of fan system, the upstairs will be warmer just from the warm air accumulating upstairs.

I usually find it best to only run the upstairs radiant systems for an hour or so in the morning, before people get up, and to limit how late the lower one runs, in the evening, in order to prevent overheating upstairs at night.

Most people prefer to sleep in a cooler upstairs bedroom, but like a nice comfortable living room for lounging around in the evening. This is where timing and careful settings make the most out of multi story systems. Also, closing the upstairs bedroom door helps.

 

[PAGUY]

John - I believe we are on the same wave length with thinking how to get it to work the best it can. The propane fireplaces (0ne up and one downstairs) would be supplemental heat for those really cold days in PA.

Again TY to all who offered their 2¢.