Jim Richardson wrote:
On Sat, 08 Oct 2005 18:03:13 GMT,
Brian Whatcott wrote:
On Sat, 08 Oct 2005 09:55:54 GMT, "Dennis Pogson"
wrote:

Courtney Thomas wrote:
How do the forced air units compare with the hot water ?

Thank you,
Courtney

I would guess that pumping hot water at low pressure through
radiators and associated piping requires a lot less power than
forced-air blowing. At least, that is our experience, and the heat
is much more evenly distributed. Also, those areas which didn't
need heat were simply turned off, or the radiator stat was turned
low to suit the environment/occupants. The system is silent, which
makes for peace and quiet. Drilling through bulkheads etc. is a
darned sight easier when the holes are merely 1" dia. or less,
against the 3"-4" holes required for air tubing. Quickly drying wet
clothing and washed items is an absolute godsend, and this alone
makes up for any disadvantages of hot water heating.

The heating unit is very quick to achieve operating temperature,
and for cold the system started to be effective in about 15
minutes. If an en-suite radiator is inadvertently left full on, the
heads would become a sauna!

Although diesel-fired, our boat seemed to survive the winter on
very little fuel, admittedly, we had 2 * 60 gallon tanks, but the
guage never seemed to move much over winter.

I am completely sold on this form of heating against the forced-air
systems.


Dennis.

Interesting observations. In countries where the need is for heating
only, nobody uses blown air. It's noisy, and its dirty.

But when the need is for cooling, circulating water systems are not
so popular.

As soon as I typed this I realised that when computer suites need
cooling, the system chosen is often circulating water chillers.
So even where cooling/heating systems are needed, there is room for
circulating water, seems to me.

Brian Whatcott Altus OK



Forced air also has some advantages. If your recirculating water
heating system springs a leak, it's a mess, and may even damage other
systems. If the forced air system leaks, then all it takes is a bit
of duct tape to fix, if you want to bother. No need to bleed air out
of it either, although that can also be avoided with a decent design
in the water circ system.

Since all the tubing is in under the sole, a leak (we have never experienced
one!), simply goes into the bilge. The observations re forced air cooling
would only apply if some form of air conditioner was in use, since the air
outside a boat in hot weather may not be all that cooler than the inside
air.

The tubing is unlike any other I have seen on boats, thick-walled and black
in colour, and with patent fittings/joints, which seem to be absolutely
foolproof.

I guess technology moves on, and we all have to try to keep abreast of it.
Last years' fittings are out of date in no time at all.


Dennis.