radiant baseboard safety

Uni R

I hope the sauna manufacturers realize this as well. They can be as high as 200F.

You do know that you can design your heating system so that it won't require 180F? Did you also know that if we touch something hot, we have reflexes that make us move away (well unless it's the other type of hot <g>)? Comparing a hot surface to coffee is silly, because hot liquid contacting us is much different and that is why coffee will burn you badly and your baseboard won't.

Dan_15

concerned about surface temperature

I am trying to convert from forced hot air to hydronic.
While investigating my options, I came across radiant
baseboards, i.e., true radiant rather than the standard
convection baseboard. I was looking specifically at
the Slimline baseboards (aluminum profile) but I see that
Weil McLain also makes one (cast iron).

Now the problem. In order to work as radiant source, the
baseboard has to be exposed. The Slimline specs talk about
running it at 180 or 190 degrees. That to me translates to
having an exposed 180 degree hot piece of metal around the
perimeter of my bedroom, at the ground level where my feet
dangle from the bed at night, and where babies or toddlers
are most likely to crawl and touch. I have seen exposed
steam radiators, but this seems hundred times worse because
the baseboard does not visually stick out, and it is
"everywhere" (you look out the window and your feet will
for sure touch it).

I asked the Slimline people, and their answer was it may
burn you, but it will not leave mark on your skin.

My questions:

Am I missing something?

Are there any contractors willing to install this
thing without worrying about being sued? After all, it
is only marginally cooler than the infamous McDonalds
coffee case.

Thanks.
Zdenek

Joe Brix

If you wrap a room

with radiant BB (even more so with CI BB) you probably will run @ 160° water at most. Hopefully you can use outdoor reset and lower that temp further if it's not that cold out. I can only see burning yourself if you chose to sit on a rad bare-skinned for a few minutes. As long as a child cannot get a finger stuck in a rad somehow, I think the reflex reaction would make you pull away from a rad before any burning would occur.

I do agree steam heating is much more dangerous and might require rad covers, but this will reduce radiation efficency.

Dan_15

I need real data

Regarding the actual temperature, I am quite cognizant of
the fact that I can run the BB at lower temperatures, but
the BTU rating will roll off rapidly. That's why the
Slimline people actually quote the BTU at 180 and 190.

Outdoor reset does not affect the max temp of the BB.

Yes your reflex reaction may help you back off with your
finger, but won't help you if you slide off your bed and
land with both feet against the BB. Nor will it help a
child rolling against it with their bare back.

Rearding your bare-skin-few-minute claim... Here are
approximate times for a third degree burn on child's
skin: 35 seconds at 130 deg F, 1 second at 140 deg F,
and 0.5 second at 150 deg F.

I am aware of state regulations for certain care giving
facilities, actually citing the facility if an accessible surface is found warmer than 140 degrees.

Feel free to experiment if you disagree, then let me know
how long you were sitting on that 180 degree radiator.


My main point is this: I suspect this product does not
put out enough heat. It probably delivers less than 100
BTU/ft when run at safe temperatures.
So they advertise 250 BTU/ft at 190 which looks better
until you realize that it would be a liability to run
it that way.
That's why I was curious if someone actually had any real
experience with it, either as the end user, or installer.

-Z

Al Corelli

Milions of people grew up in houses with steam or hot water heat, and yet, they managed to survive.

My mom taught me when I was very young. The stove is hot. The radiator is hot. Once you learn that, you avoid the hot places.

Joe Brix

I guess regular fin tube

has the enclosure, which I assume will never get as warm as the boiler water temp. As Al said, my kids have never had an interest in baseboard. I'm much happier knowing there was less chances of nose bleeds and respitory problems from a hot air system. I don't know, maybe a panel rad might draw a child's attention and looks like a target. Anything with holes in it,they probably love to stick things in. But I think the radiant baseboard would be of little interest to a child.

Chuckles_4

Your concern doesn't have to do with this particular type of radiator; it is equally applicable to any type of unenclosed radiation (e.g. an old-fashioned radiator) using 180F water. Most radiation is rated for 180F/190F water; it's standard and allows easy comparison. As others have said, you can't have hot water heat or steam heat without having hot surfaces. So isn't it surprising that hydronic heat hasn't been banned yet?

Charts of how long before a certain temperature will hurt you are meaningless; it's "science lite". That's because it depends. 180F water poured over you will hurt you because it carries a lot of heat to your body (high specific heat) and sticks to (wets) the skin, but touching a 180F metal surface doesn't have the same effect because of the weak coupling.

The rules for care facilities are there because very old people may not have normal reflexes or heat perception. For the same reason it is risky for them to use electrical warming pads (even though those don't go anywhere near 180). But your kids' heat perception and reflexes are just fine, and if not they should see a doctor.

Incidentally, the radiation needs to put out the maximum heat only on design days. The rest of the time it will get to 180 only briefly if you use old-fashioned "bang bang " heating, and almost never if you use either (a) reset, or (b) thermostatic radiator valves.

You say outdoor reset does not affect the max temperature, but this max temp will be reached only on a design day, i.e. once every few years. Maybe not even then, because the highest BTU load results in the highest temp gradient in the radiator, so 180F water will not create a 180F metal surface.

Constantin

Hear Hear!

And I learned it the hard way when my hand got stuck in a (rare) steam radiator in Germany. First, Second, and Third-Degree burns later, I had learned my lesson. Burns like that hurt.

A lot.

Particularly when they cover your entire hand.

Learned my lesson though. :-P

van_2

Radiant BB Experience

I have had a bad experience with radiant BB. It does not work well. It hardly warmed the room even when running high temps and that just defeats the purpose of outdoor reset. I removed and replaced one room with Runtal and the other room will be replaced soon.

Do yourself a favor. Use something like Runtal, cast iron or copper fin BB and you will be happier.