[Strawbale] PEX, Concrete Slab, Fear of Death (by contractor)

[Dion Hollenbeck]

At 03:37 PM 12/26/2007, David Neeley wrote:
>I would question the utility of a hydronic floor in a strawbale house to
>begin with (or, for that matter, in any superinsulated structure).
>
>There seems to be a general consensus that a three-string bale wall house
>represents about R30 to R40 (depending on many factors and who was doing the
>testing, it appears). If you couple this with superior insulation in the
>attic (seeing that the roof structure is responsible for about 65% of the
>heat gain or loss in a typical house) and decent windows and doors, the
>house should hold temperatures very well--and the lag times of a hydronic
>system would be difficult at best to deal with. Adding in the high cost of
>the system, and I cannot think it would be a worthwhile investment.

My experience over 7 years in my workshop with in-slab hydronic is 
that there are no problems whatsover with lag times.  The building 
stays within 2 degrees of the thermostat set point 24 hours a 
day.  With regards to cost, my system happens to be in the workshop, 
but is designed to produce both radiant heat and domestic hot water 
for both the workshop and the house.  The house will be build this next spring.

As for the building holding heat, it does that very well.  Once 
without any heat, indoor temp 70F, outdoor temp 10F at night, 40F in 
the day, it only dropped 4 degrees F in 24 hours. However, there 
still *is* heat loss, so it has to be made up some way.  I chose 
radiant.  This choice was considered to be the best for my situation 
because my wife hates the noise of a forced air system, and the fact 
that the system is a haven for airborne particulates, no matter how 
good the filtration is.  Hydronic just made more sense to us, 
especially after we stepped in bare feet on a friend's floor during 
the winter who has hydronic floor heat.

regards,
dion

--
Dion Hollenbeck
Email: hollen at woodsprite.com    Home Page: http://www.woodsprite.com
Brewing Page: http://hbd.org/hollen   Toys: 98 4Runner, 86 4x4 PU