Forwarding mail by: fiction-of-philosophy@xxxxxxxxxxxxx () on
10/15/94 12:31:42 PM
-------------------
Now, please, could some of the "hotshots" listed in the
self-belated "Architexture" post peruse these emcausticly
radiant postings and then postmodern-deconstruct-philosophize
them so the self-beleaguered poster does not feel self-demeaned
by slum-pleading fashionably late to a list with whose knows
who illegible institutional credentialists whose derriers sit
awaiting the late-postmoderner's list-tonguing, decon-tonguing
and philo-tonguing name chanting.
John
Forwarding Design-L mail:
-------------------
Subject: Re: Radiant heat FLW Imperial Hotel
There are only 3 fundamental types of heat transfer:
Convection, Conduction,
Radiation. While no heating system is 100% of a type, radiant
floor heating
is MAINLY radiant, convection & conduction are minimal. The
human body looses
heat by radiation and perspiration, that's why both clothes and
ambient
humidity control are so important for our comfort. The way
radiant heating
system works is by creating an equilibrium of radiant energy
that matches the
human (or the cat!) energy radiation. Radiant heating does not
work by heating
the air ( [***conduction***) that in turn travel to the body
[***
convection***] and then heat the body [***conduction***].
Physics is simplier
than that , radiant heat heats your body by *** radiation ***.
Of course, you are right to say that it is not an 100% radiant
process, and
the cat still prefers to sleep where the warm water pipes
enters the concrete
floor.
Michel de Spot. P.Eng. mdespot@xxxxxxxxxx
-------------------
>
>Also, it is an environmentally sound solution in that it heats
only what is
>needed to be heated, and can typically be driven by teeing
into a high-
>efficiency HWH, and using a little pump. For some more money,
you can get
>zone control (if needed) to follow use patterns or the sun.
>
>Mark
The only problem is that it is very slow to respond, so that
most users
simply leave it on all the time. For people who need heat for
only a
couple of hours per day, say in the morning before leaving for
work, it
probably is not as energy efficient as a conventional system
with a
programmable thermostat. I'm using it for a child care center,
which I
think is nearly an ideal application. BTW, it seems to be cost
competitive
with conventional package HVAC units, although of course you do
not get
mechanical ventilation and AC.
**********************************
Jonathan Cohen, AIA
246 First St., Suite 203
San Francisco, CA 94105 USA
email: kvetcher@xxxxxxxx
**********************************
Jonathan,
I hadn't considered the long lag time, but I think that can be
overcome with some control strategies. In larger systems, the
HWS temp. is tied to OAT; maybe that can be adapted for
smaller-scale use.
I also agree that if heating is only needed for a short period,
radiant floors aren't the best. This would seem to dictate
that they be used in the northern latitudes where there are
significantly long periods of cold (oh, like say a week or two
of -25 F? :) ). Well, it doesn't have to be THAT cold!
It's getting to the point that we're going to be picking nits
pretty soon---
our affordable house program here in Muncie is getting down to
$200/heating season with construction just meeting the Indiana
Energy Code, which is anything but cutting-edge. We're using
85% GFA furnaces and some careful construction detailing
only---we're beginning to look radiant floors and combined
domestic and heating HW systems, but I think that in small
houses, diminishing returns is going to kick in before we go
much farther.
Jonathan, I think a POE will reveal that the grownups in your
daycare center will like the radiant floor just as much as the
kids. I'm also happy to hear that it was cost-competitive w/
forced air systems. Natural cooling and ventilating strategies
might help hold the costs down further, if they can be easily
incorporated.
Mark
-------------------
End Forwards
10/15/94 12:31:42 PM
-------------------
Now, please, could some of the "hotshots" listed in the
self-belated "Architexture" post peruse these emcausticly
radiant postings and then postmodern-deconstruct-philosophize
them so the self-beleaguered poster does not feel self-demeaned
by slum-pleading fashionably late to a list with whose knows
who illegible institutional credentialists whose derriers sit
awaiting the late-postmoderner's list-tonguing, decon-tonguing
and philo-tonguing name chanting.
John
Forwarding Design-L mail:
-------------------
Subject: Re: Radiant heat FLW Imperial Hotel
There are only 3 fundamental types of heat transfer:
Convection, Conduction,
Radiation. While no heating system is 100% of a type, radiant
floor heating
is MAINLY radiant, convection & conduction are minimal. The
human body looses
heat by radiation and perspiration, that's why both clothes and
ambient
humidity control are so important for our comfort. The way
radiant heating
system works is by creating an equilibrium of radiant energy
that matches the
human (or the cat!) energy radiation. Radiant heating does not
work by heating
the air ( [***conduction***) that in turn travel to the body
[***
convection***] and then heat the body [***conduction***].
Physics is simplier
than that , radiant heat heats your body by *** radiation ***.
Of course, you are right to say that it is not an 100% radiant
process, and
the cat still prefers to sleep where the warm water pipes
enters the concrete
floor.
Michel de Spot. P.Eng. mdespot@xxxxxxxxxx
-------------------
>
>Also, it is an environmentally sound solution in that it heats
only what is
>needed to be heated, and can typically be driven by teeing
into a high-
>efficiency HWH, and using a little pump. For some more money,
you can get
>zone control (if needed) to follow use patterns or the sun.
>
>Mark
The only problem is that it is very slow to respond, so that
most users
simply leave it on all the time. For people who need heat for
only a
couple of hours per day, say in the morning before leaving for
work, it
probably is not as energy efficient as a conventional system
with a
programmable thermostat. I'm using it for a child care center,
which I
think is nearly an ideal application. BTW, it seems to be cost
competitive
with conventional package HVAC units, although of course you do
not get
mechanical ventilation and AC.
**********************************
Jonathan Cohen, AIA
246 First St., Suite 203
San Francisco, CA 94105 USA
email: kvetcher@xxxxxxxx
**********************************
Jonathan,
I hadn't considered the long lag time, but I think that can be
overcome with some control strategies. In larger systems, the
HWS temp. is tied to OAT; maybe that can be adapted for
smaller-scale use.
I also agree that if heating is only needed for a short period,
radiant floors aren't the best. This would seem to dictate
that they be used in the northern latitudes where there are
significantly long periods of cold (oh, like say a week or two
of -25 F? :) ). Well, it doesn't have to be THAT cold!
It's getting to the point that we're going to be picking nits
pretty soon---
our affordable house program here in Muncie is getting down to
$200/heating season with construction just meeting the Indiana
Energy Code, which is anything but cutting-edge. We're using
85% GFA furnaces and some careful construction detailing
only---we're beginning to look radiant floors and combined
domestic and heating HW systems, but I think that in small
houses, diminishing returns is going to kick in before we go
much farther.
Jonathan, I think a POE will reveal that the grownups in your
daycare center will like the radiant floor just as much as the
kids. I'm also happy to hear that it was cost-competitive w/
forced air systems. Natural cooling and ventilating strategies
might help hold the costs down further, if they can be easily
incorporated.
Mark
-------------------
End Forwards