Radiant Heat isn't about the feet....

Tony_23

John

We are in agreement, already. Re-read my posts and read the one below. You will see

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Tim_33

Never

never seen any type of avdertising that was not absolutely, 100% truthful, the whole truth and nothing but the truth. Never. :-!

I believe that I was mistaken in my belief that the radiant side was wrong. So,have we beaten this one enough yet?

Tim_33

John

I haven't, but seems as many of you have. I would be interested in specific methods and results of actual air temperature measurements in a RFH heated room.

Mike T., Swampeast MO

Check out this Article

Note the ultimate goal when loads are reduced and radiant panels provide the heating/cooling: Batiment Isothereme "Constant Temperature Building" with radiant surfaces maintained year round at 22°C (71.6°F)...

BTW, I searched high and low for temperature gradient drawings using forced air or radiant panels from at least reasonably authoritative sources. ZILCH! I did however find an exhaustive study of panel radiators from New Zealand. Such showed temperature gradients rather similar to what I have measured in my house in areas with standing iron radiators. When undisturbed, my radiant baths (9' ceilings) show extremely little temperature stratification, <1°F.

Fred Campbell

Great article

Mike, That was very informative. I particularly liked the mention of prevailing wind ventilation. And of course the water distribution over air thing. Just curious... What kind of temp variations are you getting in your standing iron rooms? I know you're running the radiators low temp with a Viessman so I'm curious.

TG

Mike T., Swampeast MO

Only measured once in one room and that was before the Vitodens but the TRVs and constant circulation with no periodic setback. With about 59F below the floor and 65F near the breathing line, believe it was about 63F an inch above the floor and 70F an inch below the 9' ceiling with conditioned space above--forced air at about 68F thermostat setting.

This with the ceiling fan off for over 24 hours (the only time it's ever been off in years.) Will try to look for the actual data tomorrow. The 7F differential between floor and ceiling sticks in my head. This from a real-time series of posts a few years ago, but believe I printed.

Impossible to compare to the "Eurocave" the past heating season as the ceiling fan was constantly running and I used a frequent warm-air boost. While I don't wear a skirt, my feet are under a desk facing an outside wall corner. White crew socks and athletic shoes. Feet uncomfortably cool on overcast humid solar periods with outside temps in the 35-45 degree range and rad temp 70F-72F for entire solar periods.

"Damp cool" seems to reduce human comfort similarly to "humid warm"....

Fred Campbell

Cool at the Ceiling

I've experienced noticible cool at the cieling of low temp radiant floor at 9'. No hard data but the room was at 72* at stat, tile floor at 77* surface by infrared (they complained the floor wasn't warm and in so many words I told them to shut up and enjoy...isn't that what this post's about?). Sometime later I was in the same room (heated above) and 'percieved' it was cooler near the cieling while I was on a ladder. Mike, that was the same house I got my very own "Myson Ring". Remember?

In low temp radiant rooms with insulated attic and drywall I KNEW it was cooler up there while on a ladder. Again no data so I guess I could be blowing smoke.

I've worried about stairwells against outside walls in some of my radiant houses due to the lack of stack effect. No complaints though. I guess the folks just don't spend enough time hanging out on the stairs.

Leo G_99

wells' youse is both rong!

> You stated "...The air has to be moving past you

> for it to work. This movement of air is

> constantly changing your body temperature. You

> either feel to cold or to hot depending if the

> air is warmer or cooler then required. "

>

> This

> is just plain false. IF you were in still air at

> 80 degrees, would you feel warm? IF you were in

> still air at 30 degrees, would you feel cold? The

> answer to both of these questions is "Yes". You

> agree?

>

> Unless there is a problem with you or

> the controls of the system, you do not either

> "feel too cold or too hot".

>

> You state that you

> are comfortable all winter. I have a forced air

> system and I can state exctly the same thing: I

> am comfortable all winter. This is a fact. (But I

> can add: also, all summer.) I can add humidity to

> my house if I want to and can control it at any

> reasonable level I choose, can you? I bring in

> fresh air via my system all winter long, can you

> do that with your system? I can recover the warm

> air that collects near the ceiling of my great

> room with the always used fireplace, and

> recirculate that throughout my house, can you? I

> can cool and dry the air with my system. Can you

> do that? I can filter and treat the air in my

> home with my system, can you do that?

>

> I have

> experienced a radiantly heated home. YOU have

> obviously never experience a properly done forced

> air system if you believe what you say.

>

> The

> bashing is that you (and others who) are either

> doing so purposefully or out of ignorance(you

> choose) are grossly overstating the comparative

> comfort.

>

> IF you are in a home with radiant

> heat you will always hear water noise screaming

> through controls valves, right? It must be so

> because I witnessed this once myself. So because

> of one poorly designed and installed system, I,

> like you are doing, can by extension, condemn

> every similar system of the same faults, right?

> WRONG, I cannot, and I know better. But you seem

> to beleive that all forced air systems are drafty

> and uncomfortable, because that is what the

> common "line" is for your trade, or so it seems.

> Further ignorance is evidenced in the fact that

> you believe that, with warmer than air floors, a

> radiantly heated space is not subject to air

> currents. Impossible.

>

> I agree with the fact

> that a well done radiant system is very

> comfortable and quiet. I do have radiant heat in

> portions of my home (my garage and tile floors).

> I also know for a fact that a well done forced

> air system is not that different, in that it too

> is very comfotable.

Leo G_99

wells' youse is both rong!

I heat my house with a Velenco forced draft wood burning fireplace. I still think that this is the most comfortable heat ever, even when the TV room gets into the high nineties!

Leo G

Leo G_99

TG

Some of the places that we install radiant have over 500 pot lights. Did one place where the "gourmet" kitchen had 120 pots'. Am seriously thinking about down sizing my boilers to about 80% of the heat load. I don't think that kitchen floor ever gets warm!

Leo G

Mike T., Swampeast MO

How could I forget the Myson ring? Craziest and most finicky connection I've ever seen. Just hope I remember where I put the spares I bought while in London.

I haven't carried a thermometer with me when decorating trees in forced air heated spaces VERY similar to the illustration here that's causing so much problem, but I know "stifling" when I feel it. This even near the LOW end.

GMcD

Batiso Buildings

There are some examples of those buildings up here where I and Vladimir live- Vlad and I spent some time in Europe studying these building systems back in the late '90's - he's now at Cobalt and I'm at Omicron AEC. The key thing is that the mechanical engineer must design the building envelope performance and components side by side with the Architect - lower the loads first, then design appropriate heating/cooling systems. Check out some of the material that Transsolar does, as well as Battle McCarthy. The new wave of building design, including homes, is to design them for as much passive performance as possible, to maintain comfort with the minimum added mechnanical system energy possible. This means spending the $$ on the envelope, something that North American builders can't seem to wrap their heads around due to the almighty motivation to build cheap and fast.

John Ruhnke

Love the article..........

Mike,

Thanks for posting that article, I loved it!

JR

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