Q & A Radiant Heat All information that follows are opinions of individuals. The "Authority Having Jurisdiction" (local building department) has the final say in whether an installation is "to code".
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Q & A Radiant Heat All information that follows are opinions of individuals. The "Authority Having Jurisdiction" (local building department) has the final say in whether an installation is "to code".
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Subject: Re: Radiant Hydronic DIY?
Date: 5 May 1997 10:25
From: aab@cichlid.com (Andy Burgess)
Newsgroups: misc.consumers.house , sci.engr.heat-vent-ac
References: 1
>Can anyone help me. I have a 1000 ft.sq single story house that
needs a
>new furnace. I would like to install radiant hydronic heating tubes
in the
>joists in the basement to heat through the floor of the main floor and
>install a boiler to heat the home. I can do most of the work myself.
>What I would like to know is what would I be looking at for cost
of
>supplies?
I suggest getting two publications. One is the Heatway installation
manual (www.heatway.com, you want the installation manual not
a brochure). Also search www.amazon.com for hydronic, there is a book
by a HVAC engineer thats pretty good (he has an article in a recent
issue of Fine Homebuilding). Its $50 or so but you're going
to save many $$$ by doing this yourself. Anyway with amazon you can
return the book if you don't like it.
To me it looks like the heatway synthetic rubber tubing is easier to
handle than the PEX tubing. I'm in the same situation as you and I'm
planning to install one 200 foot loop of heatway this summer to see how
it goes. If I like it I'll finish the house with it, otherwise switch
to PEX. PEX is much stiffer than the heatway tubing, heatway is like
automobile heater hose. Heatway also doesn't require heat spreaders
which triple the installation cost per sq foot. (The tubings are about the
same cost per foot). Heatway requires a radiant barrier under the
tubing but since you have to insulate the joist bays anyway this doesn't
seem to be a problem, just use foil backed fiberglas or foil backed
polyisocyanurate board. Whether it works I will find out :-)
My house is 1150 sq ft but my heating requirements are only
5 BTU/sq ft/hour, probably much less than yours so I can go with
a domestic hot water heater as a heat source with solar supplimental
(pure solar most of the time).
You're lucky you can do it from a basement, I'll be eating dirt in
a crawl space...
----------
Subject: Radiant Hydronic DIY?
Date: Mon, 05 May 1997 23:20
From: sscott@light-link.com (Steve Scott)
Reply-To: sscott@lightlink.com
Organization: I SPEAK ONLY FOR MYSELF
Newsgroups: misc.consumers.house , sci.engr.heat-vent-ac
On 5 May 1997 10:25:40 -0700, aab@cichlid.com (Andy Burgess) wrote:
>
>>Can anyone help me. I have a 1000 ft.sq single story house that
needs a
>>new furnace. I would like to install radiant hydronic heating tubes
in the
>>joists in the basement to heat through the floor of the main floor
and
>>install a boiler to heat the home. I can do most of the work myself.
>
>>What I would like to know is what would I be looking at for cost
of
>>supplies?
>
>I suggest getting two publications. One is the Heatway installation
>manual (www.heatway.com, you want the installation manual not
>a brochure). Also search www.amazon.com for hydronic, there is a book
>by a HVAC engineer thats pretty good (he has an article in a recent
>issue of Fine Homebuilding). Its $50 or so but you're going
>to save many $$$ by doing this yourself. Anyway with amazon you can
>return the book if you don't like it.
Are you thinking of the book by John Seiganthaler?
>To me it looks like the heatway synthetic rubber tubing is easier
to
>handle than the PEX tubing. I'm in the same situation as you and I'm
>planning to install one 200 foot loop of heatway this summer to see
how
>it goes. If I like it I'll finish the house with it, otherwise switch
>to PEX. PEX is much stiffer than the heatway tubing, heatway is like
>automobile heater hose. Heatway also doesn't require heat spreaders
>which triple the installation cost per sq foot. (The tubings are about
the
>same cost per foot). Heatway requires a radiant barrier under the
>tubing but since you have to insulate the joist bays anyway this doesn't
>seem to be a problem, just use foil backed fiberglas or foil backed
>polyisocyanurate board. Whether it works I will find out :-)
Food for thought here. Why do you think you need transmission plates
with PEX but not rubber tubing? Is there an adequete oxygen barrier
with the Heatway? What's Heatway's track record in the industry?
Talk
with those that installed it 10-20 years ago.
>My house is 1150 sq ft but my heating requirements are only
>5 BTU/sq ft/hour, probably much less than yours so I can go with
>a domestic hot water heater as a heat source with solar supplimental
>(pure solar most of the time).
Are you using the W/H only for heating or to provide DHW as well?
>You're lucky you can do it from a basement, I'll be eating dirt
in
>a crawl space...
Ugh
Please remove the - between light and link to reply.
Sorry for the hassle but I'm sick of junk mail.
** The problem with the average family today is that it's
impossible to support it and the government on one income.
----------
Subject: Re: Radiant Hydronic DIY?
Date: 6 May 1997 12:37:11 GMT
From: JamesL@Godfrey.com (James Leatherwood)
Organization: Godfrey Public Relations
Newsgroups: misc.consumers.house
In article <5kl56k$dna$1@loach.cichlid.com>, From aab@cichlid.com
(Andy
Burgess), the following was written:
> If I like it I'll finish the house with it, otherwise switch
> to PEX. PEX is much stiffer than the heatway tubing, heatway is like
> automobile heater hose. Heatway also doesn't require heat spreaders
> which triple the installation cost per sq foot. (The tubings are about
> the same cost per foot). Heatway requires a radiant barrier under
the > tubing but since you have to insulate the joist bays anyway
this
> doesn't seem to be a problem, just use foil backed fiberglas or
foil
> backed polyisocyanurate board.
Well, yes...but...
Heatway is having some problems with product longevity. I.e., their
tubes are falling apart after a few years. They're on (at least) their
third generation of tube design.
PEX, on the other hand, has been widely installed in European homes
since the early 70s (and in expensive homes since the 40s), with no
significant failure rates. Wirsbo (PEX A) and several other companies
guarantee their PEX tubing for 25 or 30 years. The largest manufacturer
of PEX in Europe (OY Uponor) is introducing to the US market a new
formulation, PEX C, which uses an electron beam to *mechanically*
crosslink the polyethylene (as opposed to PEX A and B, which use a
chemical reaction). The result is a more durable, better tube with
better heat transfer.
As for radiant barriers...installing a radiant barrier underfloor is
tricker than you might expect. You need to allow air space between the
subfloor and the radiant barrier, and the spacing needs to be precise to
within less than 25% -- not a bad margin if you're talking a foot or so,
but (AFAIK) the allowable space is about an inch. You also might want to
allow some way of getting into that space later on -- as dust
infiltrates the radiant barrier air space, it settles onto the foil,
reducing the reflectivity (and therefore heat trasnfer effectiveness).
It takes longer, and costs more, but stapling the tubing directly to
the
subfloor and then stapling up heat transfer plates, though the plates
are not necessarily crucial.
For more information, call the Radiant Panel Association at
1-800-660-7187. Or call Burnham Corp. (a boiler manufacturer) at (717)
393-4701 and ask to speak to Jim Roche -- their radiant expert.
Even though I do some work for Burnham, the opinions expressed above
are
my own.
James Leatherwood JamesL@Godfrey.com
05/06/97 08:18
--------
Subject: Re: Radiant Hydronic Heating Question
Date: Wed, 07 May 1997 20:51:30 -0400
From: sscott@light-link.com (Steve Scott)
Reply-To: sscott@lightlink.com
Organization: I SPEAK ONLY FOR MYSELF
Newsgroups: misc.consumers.house , sci.engr.heat-vent-ac , alt.solar.thermal
On Wed, 07 May 1997 14:45:22 +0100, John Tvedte <compsol@cid.infi.net>
wrote:
>How about some comments on:
>
>Circulators vs. zone valves- reliability - flow issues - etc.
I use both in a radiant system. You generally need a high head pump on
the tubing side while other loops would be better suited with lower head
pumps. I use the zone valve in place of flow checks because flow checks
have a nasty problem of not always closing giving you heat in the
darnedest areas. A zone valve will shut down 100%.
>3ways vs. injection systems (ie: tekmar) - in general boiler and system
I use 4 way valves. I think they're less likely to give you problems
long term.
>controls - protecting the boiler & floor temps -
A 4 way in combination with inside and outside sensor is the way to go
with radiant, IMO.
>Outdoor reset controls
> manifolds - are the cheaper copper ones usable...
> ways to make a less expensive system - but one that is still high
>quality
Personally, I don't like the look of them. You're going with an
expensive system and one of the few things you use looks chincey. I do
use copper but I sweat everything.
Please remove the - between light and link to reply.
Sorry for the hassle but I'm sick of junk mail.
----------
Subject: Re: Radiant Hydronic DIY?
Date: 8 May 1997 13:00:32 -0400
From: finkej@ts.its.rpi.edu (Jon Finke)
Organization: Rensselaer Polytechnic Institute, Troy, NY
Newsgroups: misc.consumers.house , sci.engr.heat-vent-ac
, alt.solar.thermal
In article <33708771.72D195F@cid.infi.net>,
John Tvedte <compsol@cid.infi.net> wrote:
>
>How about some comments on:
>
>Circulators vs. zone valves- reliability - flow issues - etc.
>3ways vs. injection systems (ie: tekmar) - in general boiler and system
>controls - protecting the boiler & floor temps -
>Outdoor reset controls
> manifolds - are the cheaper copper ones usable...
> ways to make a less expensive system - but one that is still high
>quality
I have an 8 zone radiant heat system with an outdoor temperature sensor
and computer controlled mixing valve - the temperature of the water
in the system is set based on the outside temperature (including time of
day setbacks, etc). The circulator is always running, so there is heat
coming from the system at all times.
In the design phase, we calculated the heat loss for each room/zone,
and
figured the amount of heat each room needed - this directly translated to
the number of feet of radiant panel in each room/zone. In this way,
each zone gets the exact amount of heat needed to maintain comfort.
Just in case things are not quite right, there are controls on the computer
to change the heat curve based on outside temp, and the manifold has
two valves per zone, one is an on/off valve (that can be electrically
controlled - don't bother) and the other is a flow adjustment, so if one
room is too warm, you can reduce the flow, and reduce the heat output.
(if one room is too cold, add more feet of radiant, or turn UP the central
control and tweak all the other zones down.)
So far, I have run with all zones wide open, and have not used the electric
controls. Since the valves are set once and left - they seem to be rock
solid in terms of reliability - no moving parts.
| (Photo of the setup available from my web page) | ||
| -- | ||
| Jon Finke | finkej@rpi.edu | |
| Senior Systems Programmer | http://www.rpi.edu/~finkej | |
| Server Support Services | 518 276 8185 (voice) | 518 276 2809 (fax) | |
| Rensselaer Polytechnic Institute 110 8th Street, Troy NY, 12180 | ||
----------
Subject: Re: Radiant Hydronic DIY?
Date: 13 May 1997 13:19:01 GMT
From: really_eliot@dg-rtp.dg.com_but_mangled_to_stop_junk_email
Organization: Data General RTP
CC: eliot
Newsgroups: misc.consumers.house
As for radiant barriers...installing a radiant barrier underfloor is
tricker than you might expect. You need to allow air space between the
subfloor and the radiant barrier, and the spacing needs to be precise to
within less than 25% -- not a bad margin if you're talking a foot or so,
but (AFAIK) the allowable space is about an inch. You also might want to
I find this statement that the location of the barrier is critical rather
hard to believe. Could you please tell us where you got this information?
Thanks.
Topher Eliot Data General Unix Core Development
(919) 248-6371 eliot at dg-rtp.dg.com
Obviously, I speak for myself, not for DG.
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