Doctor Drivel wrote:
wrote in message

forced air is a cheaper alternative to rads (to install),

Not so. About the same in new builds.

and has a few
drawbacks:
- noise

Not so. The latest units are very quiet. A lot has happened since 1991.
Also, it is worth having the cupboard sealed up too. Not a big job.

- dust blown about

Not so. The latest units have electrostatic air filters which are recommend
for asthmatics.

- whiffs transferred round the house

Not so. The filters kills any smells.

What you spouted are the old wives tales of forced air. Forced air can also
cool a house by circulating air.

Hence it remains unpopular in UK.

Because of old wives tales and poor, cheap installations.

In US OTOH its the standard method.

The US know how to fit them.

Run costs are similar,

Not so. Forced air is usually cheaper.

the big fan means more on the leccy bill, and a
bit less on the gas, but overall a bit more money.

Nope.

Replacing an old system would improve run costs if the new boiler is
more efficient, but not not if its the same efficiency.

I used to have
radiators in another house and when they first came on they used all the
hot
water until it heated up again as I found out when I started to run a
bath
just as the timer switched the radiators on, but that was a coal fired
system.

ah. If that happened on a gas system it would be lousy design. HW gets
priority. Coal systems tend to lack proper controls.

Another cost saving would be that I would no longer need a maintenance
contract with Scottish gas as there is less to go wrong with a radiator
system than a warm air system.

no theres more. Forced air is just a big fan and ducts, a hydronic
system has plumbing, rads, pump, header tank, TRVs, inhobitor,
ballcock... thats why forced air is cheaper to install.

Forced air is not cheaper to install. In some homes where the house was
designed around the units that may have been the case.

Dry system are superior to wet systems. As soon as you put water in a
container it wants to get out. And eventually it does. Wet system sludge
up too. A modern sealed CH wet system is more problematic than a forced air
system. ....and no ugly rads on the walls.

New registers can be fitted to give better and in some case auto control.
Some registers are motor controlled and open and close to a room stat. When
most registers are closed the fan motor drops its speed to suit so no noise.
The fan motor also drops it speed when up to temperature too. All easily
updated.

Johnson & Starley make direct replacement units which are a world away from
the old units, with electrostatic air filters, modulating fans and burns via
electronic control.

Look at:
http://www.plumbingpages.com/forums/...s.cfm?Forum=16

It is a no-brainer......keep the forced air system, with new
state-of-the-art unit.


Thank you for the good information Dr Drivel. Yep, you heard!

I used a building with 1970s hot air heating, and it was as I
described. Quite workable, but clearly not as good as hydronic. But as
Drivel kindly pointed out, all these issues are quite overcomeable.


NT