MR>There are many types of radiator heating among which is high pressure
MR>steam as you noted. Generally high pressure steam is used for larger
MR>dwellings such as multi-apartment housing.
MR>The type of gravity hot water system uses water who's temperature never
MR>gets much above 180F and operates at atmospheric or more typically at
MR>utility water line pressure. To accommodate changes in volume due to
MR>temperature expansion, it uses either an expansion tank or a pressure
MR>regulator from the water utility feed.
O.K. I am intriqued. Does this system work with a system where the heat
source is below the heat exchanger???
I have had experience with radiant baseboard heating, but the heat
source was always above the heat exchanger or at same level...in my case
the heat exchanger is going to be at least 15 feet above the heat
source. Please describe your system if it would be applicable.
MR>The main problem with the gravity hot water system is that radiators
MR>further from the source must be larger because the water is cooler at
MR>the end of the pipe. The main advantage is the more even temperature
MR>fluctuations though steam and pump fed water will respond more quickly
MR>to demand. Basically it's a design which requires more skill in
MR>selecting pipe sizes than steam or pump circulated.
Exactly, I can imagine that the system you are describing more than
likely was a floor radiant system...which is not my challenge. ++++++
MR>Yes, I had a gravity hot water system without any pumps. From what
MR>you've described so far it seems your projected system will have a
MR>relatively small capacity. I think gravity feed could work well in a
MR>small system, provided the pipes are of adequate size, since the
MR>difference in water density only results in small forces. For example
MR>3/8" tubing might just not be up to it.
MR>Which reminds me, in a mechanical flow system, one way the pump is kept
MR>from getting hot is to install it at the cold end instead of the source
MR>side. Of course circulation will probably be less than if the pump is
MR>designed for vacuum operation.
Gee, I had thought it would only work at the high  end...but since I was
working on a closed system principle, I did not expect a profound temp
differential. With an additional pump It appears I  could incorporate
the city pump system and include a large mass thermal storage area like
a spa or pool if a backflow could be incorporated.
MR>I must admit to only having cursory knowledge of heating systems so that
MR>I can't give you the many details you will undoubtedly need to complete
MR>your project. I strongly suggest you get over to a public library and
MR>get a hold of the many resources on the subject.
MR>The computer control programs themselves are rather trivial to
MR>implement. I would probably concentrate more on the physical aspects of
MR>your project 1st to ensure its success since you have a pressing need.
Well, if I could obtain parts for my 1986 YORK heat pump; ie the
"trivial" computer control" then I would not have too worry about
dealing with trivial problems such as funneling an alternative heat
source to the one remaining functional part of my furnace...the fan!
I'll be damned if I will pay 1,500 to some guy that knows less than I do
about refrigeration to tell me that which I already knew regarding MY
equipment! It used to be that a homeowner or person knowledgable in such
matters could obtain parts...not anymore (at least in USA)!  I actually
had some joker come out to my home representing YORK; who apologized for
not bringing his tools; or containment MANDATES and asking ME for a
screwdriver! I summarily excused him from my property in no uncertain
terms!
To any viewers:   please feel free to forward this response to York
Industries, they are fully aware of my situation.  Perhaps then they
would be presured to REINTRODUCE their former practice of supplying
their parts to INDEPENDENT parts houses, instead of constricting the
free supply of parts to their "preferred" distributors eg. the ones that
pay a kickback??? Where is the Federal rand Jury when you need em??
'
---
 * OLX 2.1 TD * It's only a hobby ... only a hobby ... only a
--- HyperMail! v1.22
---------------