Radiant heat better than baseboard?

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I'm getting my kitchen torn out and remodeled, even a new floor. Since it's a mud-job, the contractor told me to go with radiant floor heating... he said it's much better and more efficient than baseboard heating. I have baseboard in there now, but it would be removed in order to make room for a bench, etc. He claims -- why put in more baseboard or toe-kick baseboard heat when you could install radiant heat since the floor is up. So, is it better? What are your thoughts? Thanks!
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I'd go with the radiant. I rarely wear shoes in the house. You are going to have a tile floor, so just think how much more comfy your feet will be in the winter. In my house the floor is even cooler by the door. Radiant would solve that. This is a good time to make the change.
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It is not so simple your baseboards are probably taking a much higher water temp then the plastic radiant hoses can handle . A guess is radiant will not take 140 but but your house baseboards and your present water temp is set much higher say 160-190. There may be some equipment that can temper the radiant loop. . Then there is electric radiant to see if that is worthwhile you have to know your price comparison of gas to electric. Im in the midwest and my electric cost is 3x that of NG gas per BTU. Radiant is best especialy if ceramic or stone will be use for flooring or the basement is much cooler, but it depends on how you do it.
You need a real heating HVAC pro out to do a load calculation and all, who has done this before. Not a contractor guessing, if it is not done just right you will be very very unhappy.
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Ransley, get your head out of your bottom part.

PEX tubing will take 140 water.

There's a lot of equipment out there that will do that.

Radiant can be put under any surface, wood, carpet, ceramic, marble, etc....

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Whats your point Heat Man, Im just pointing out what the OP may not have been told. Suppose Contractor runs 180 through the loop because he is like Dave.
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PEX can take 180. Check out the manufacturers. It is tested for 210 @ 100 psi
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That doesn't matter. You CAN NOT run 180 water into a radiant floor. Suppose a baby or older person walks out onto that floor in bare feet? A mixing valve can take care of this for you.
--
Like, in not getting harsh winters, y'mean? As I look out my window
upon the British landscape it's white with snow and colder'n a witch's
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So pex can take 180, good , can the floor , can your Feet. At 180 you could put a pot of beans and a pot of stew on the floor and have it cooked when you awake. I think crock pots cook at 160. Radiant floor should be warm , not hot. Ive lived with radiant and the floor was a comfortable Warm. My point is they need a pro to calculate load and plan it and do it right. It may need its own loop, tempering, thermostat and pump as the radiators will operate at a higher temp with more mass. When you mix systems, ex. Large cast iron radiators, baseboard, radiant, or fan forced HW heat on the same system unless you know the trade mixing often means uneveness in heat. The previous owner of my residence removed cast iron radiators in one room to make for more room and put in high out put fan forced heaters , but he forgot radiators hold heat for an hour, so the room never stayed warm. So I ripped them out and brought back in the original and all is fine. Im just pointing out a pro is needed to be sure it is done correctly. Hacked in it will be bad.
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I don't know exactly what temperature the floor will be, but it will not be 180 degrees. The water leaves the heater and begins to lose temperature along the way. Once it is in the tubing, the heat is spread out along the floor giving a lot of dilution. I understand you point that it may be hotter than needed, but you are well aware of the laws of physics and heat distribution.

I agree with that.
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Ed radiant loops are often set to 110 or things can get a bit uncomfortable under foot if you know what I mean. You dont just mix it into a different system , you give it its own loop, pump, tempering devise and thermostat. Or you are guessing about success. A real pro is needed to do it right.
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Often set to is a good point. 110 won't usually do squat under a carpet, though.
Okay, 'm Ransley,' since you're now such an expert, what's the optimum floor temp for a radiant floor?
You're almost as bad as HVAC Fella sometimes

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Im no Hvac pro, I dont know Optimum temp, only that 180 is too warm. Dave ? he lies for a sale. Im just a H.O. Didnt you hear him say Goodman is all great equipment now, it just got better since that is his main product.
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My boiler is set to 140.
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Heat man: they are having a ceramic floor in kitchen, what do you recomend
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Keeping warm via hot air: works by conduction, but not conduction like sitting bareassed on a warm block of steel (much heat transferred to you per second),
but via super UN-dense air, with minuscule ability to store heat (per cubic foot) than eg steel.
I recall from a thermodynaics course eons ago that whatever the materials, the amount of heat energy flowing from one to the other, per second, is 100% *proportional* to the temperature *difference* between the two.
So, while an 80-degree (F) block of steel would be able to transfer enough heat to you (r butt) to keep you toasty comfortable even with an open window with 30 or 40 degrees outside, perhaps, no can do via hot air. Temp diff must be much greater than the 99.6 - 80 = 20-degree difference via the block of steel.
So you gotta blow hot air at you for the same warming, but so hit that it's stifling (sp?), making you feel really crappy, even nauseaous.
Then, there's heating via radiation, like by a cast-iron radiator, an electric (fanless) radiator, the sun, etc.
Those pictures of resort-like ski-areas, all these people lying around a swimming pool, in their bathing suits, when it's maybe 30-degrees -- they're kept warm by radiation from the sun (and by having the wind blocked).
And it's a *much* nicer experience than being kept warm only by a blast of hot air (sun blocked from warming you).
--

Nice thing about cast-iron radiators is that you can
open the window, allowing nice (cold) fresh air to
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I'm afraid you recall wrong, for radiation.

It would cool your butt, compared to a pillow.
Nick
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wrote:

With respect to conduction, yes...

Tell you what: you drop trou, then sit on an 80 deg F block of steel, and tell us if it feels warm. Stay there a while.
This may come as a surprise to you, but if a 98.6-degree human sits on an 80-degree block of steel, the direction of heat transfer is *from* the human, *to* the steel. Not the other way around. After thirty minutes bareassed on that block of steel, you're going to be shivering.

Nonsense. Forced air heat isn't "stifling" hot.

Uh-huh. Right. I guess you mean 30 deg *C* here.

Different strokes...

You have an *odd* definition of "warm".

Well, that's the source of your trouble - you shoulda used an air conditioner.
-- Regards, Doug Miller (alphageek at milmac dot com)
Nobody ever left footprints in the sands of time by sitting on his butt. And who wants to leave buttprints in the sands of time?
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Doug Miller wrote:
Combs) wrote:

It is also true for Newton's law of cooling which governs conventive heat transfer. Radiant floor heating heats your feet by conduction and the air in the room by convection. Radiative heat transfer is negligible, the descriptor 'radiant' is a misnomer, similar to the 'radiator' in a car.
...

on an

the human,

bareassed on

Agreed but with the caveat that 98.6 is the normal temp for under your tongue. I dunno what the normal temperature is for your butt cheeks.

The first two examples heat by convection. Radiative heat tranfer is negligible in a convective environment for such small temperature differences. Even though readiative heat transfer is proportionate the difference in the Fourth Power of th eabsolute temperature, the coefficient is typicall very small compared to the convective heat transfer coefficient so that free convection dominates unless in a weightless environment (but still dominates if there is a fan), or a vaccuum.

I don't think so.
--

FF


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Conventive? :-)

Not much, compared to the rest of your body.

Wrong.
A 90 F body in a 70 F room might lose 30 Btu/h-F-ft^2 by convection and 0.1714x10^-8((90+460)^4-(70+460)^4) = 22 Btu/h-F-ft^2 by radiation.
Nick
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snipped-for-privacy@ece.villanova.edu wrote in message (David Combs) wrote:

I think it's wise that when it comes to calculating convective heat transfer in radiant heated spaces that the conditioned panel orientation should be considered...ie: wall, ceiling or floor and whether the panel is in the heating or cooling mode and also what % of the surface is mechanical conditioned. The other calculation which influences the convective component is the MRT vis a vis AUST.
Here's a link to a spreadsheet which considers most of these factors.
http://www.healthyheating.com/solutions.htm
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