First off, the posting was to the OP and I think the OP is the only one
who can truly comment on it. Second off, it's a 300 year old house
with 3 forced air systems. Dollars to donuts, to has numerous
additons, outcroppings, etc. Thirdly, it is 100 years old, so no
matter what, it isn't sealed up and insulated like a new house.
Fourthly, he has furnaces but no central AC, so it is a good guess that
this house isn't in south Florida. It is probably somewhere north of
the Mason-Dixon line. Finally, with oil/gas/electric being up as high
as it is, everyone has high heating costs.

So go chill out.

My point is, and you seemed to miss it entirely, is that if he truly
wants a multi-zone chilled water system, it might be worth looking into
a heat pump. It would add some cost but might also add some benefit.
And if he/she does that, he/she might have some savings on heating to
help pay for a system that will probably be a little on the expensive
side. And please don't say that they might not be expensive, because
yes, they are expensive. But the might be worth the cost ... or they
might not be. That would require a bit of research and would be for
the OP to decide.

wrote:
On 15 Aug 2006 19:26:17 -0700, "Pat"
wrote:

One house and 3 furnaces = high energy bills.

Bull****.

You have NO IDEA what size house, what environment, what heat
loss, etc. And thusly, your comment is meaningless drivel.

Water AC system will not
be cheap.

I'm not sure if this would will work, but you should look into a
ground-linked heat pump system. I think some are water systems plus
you might be able to use it to heat your house.

blueman wrote:
Our 100+ yr old house currently has 3 separate forced hot air
gas-fired heating units.

We would like to add central air sharing the same ductwork and
blowers.

The "traditional" approach would be to add a separate
compressor/evaporator for each of the 3 heating units.

I have seen that some high end remodels are using a single chilled
water unit to supply coolant to multiply blower units and that this is
somehow "better".

Can anyone comment on the pros/cons and appropriateness of using such
a system residentially?

I am particularly interested in comparing initial cost (equipment &
installation), efficiency, noise-level, and reliability.

I will be hiring a reputable HVAC contractor for the installation.

Thanks.

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