"Rod" wrote in message
...
T i m wrote:
On Wed, 9 Apr 2008 00:10:08 +0100, "Doctor Drivel"
wrote:


External insulation, triple glazing and air-tightness will probably drop
that by half.

So, with all this air-tightness don't we suffocate? After we
hermetically seal the house we have to fit more air bricks?

Are there any 'domestic' Air-to-air heat exchangers that are actually
worth installing yet (both from their payback and functionality) and
from a d-i-y pov?

Technically domestic (because it is fitted to a house), the Grand Designs
house built into the ground up in the Lake District for a vet and her
family had one. (Reshown in extended form just a few weeks ago.) The
*claims* were that it is staggeringly efficient and wonderful...

But as to fitting it to an existing house, I doubt it.

There are many Heat Recovery and Vent systems around. Even Baxi did, or do,
one. Fitting them to existing hosue is venting it twice. You have to start
to seal up the fabric of the building. Once pretty well air-tight then they
shine.

"dennis@home" wrote in message
...


"Rod" wrote in message
...
T i m wrote:
On Wed, 9 Apr 2008 00:10:08 +0100, "Doctor Drivel"
wrote:


External insulation, triple glazing and air-tightness will probably
drop that by half.

So, with all this air-tightness don't we suffocate? After we
hermetically seal the house we have to fit more air bricks?

Are there any 'domestic' Air-to-air heat exchangers that are actually
worth installing yet (both from their payback and functionality) and
from a d-i-y pov?

Technically domestic (because it is fitted to a house), the Grand Designs
house built into the ground up in the Lake District for a vet and her
family had one. (Reshown in extended form just a few weeks ago.) The
*claims* were that it is staggeringly efficient and wonderful...

But as to fitting it to an existing house, I doubt it.

Maybe http://www.wickes.co.uk/invt/156417 ?

That may be an a/c system rather than heat recovery ad vent. The explanation
is poor.

On Thu, 10 Apr 2008 01:49:18 +0100 Andy Wade wrote :
Doubtless true for fuel costs alone, but what's the answer when you
factor in the capital cost of the heat pump and its source, and
maintenance...?

The capital cost is an issue, but the maintenance should (dangerous
word, I know) be minimal: my last fridge ran for 20+ years without any
problems and a heat pump is really just an oversized fridge. If I were
one of the 90% who doesn't DIY when it comes to CH I would have spent
a good few thousand pounds on CH servicing, repairs and boiler
replacement over that period.

--
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk

On Apr 10, 7:19*am, "Doctor Drivel" wrote:
"Rod" wrote in message

...





T i m wrote:
On Wed, 9 Apr 2008 00:10:08 +0100, "Doctor Drivel"
wrote:

External insulation, triple glazing and air-tightness will probably drop
that by half.

So, with all this air-tightness don't we suffocate? After we
hermetically seal the house we have to fit more air bricks?

Are there any 'domestic' Air-to-air heat exchangers that are actually
worth installing yet (both from their payback and functionality) and
from a d-i-y pov?

Technically domestic (because it is fitted to a house), the Grand Designs
house built into the ground up in the Lake District for a vet and her
family had one. (Reshown in extended form just a few weeks ago.) The
*claims* were that it is staggeringly efficient and wonderful...

But as to fitting it to an existing house, I doubt it.

There are many Heat Recovery and Vent systems around. *Even Baxi did, or do,
one. *Fitting them to existing hosue is venting it twice. *You have to start
to seal up the fabric of the building. *Once pretty well air-tight then they
shine.- Hide quoted text -

- Show quoted text -

Electricity here (Windy and cold next to the North Atlantic, Eastern
Canada) it costs the average homeowner an average of something around
ten cents Canadian per kilowatt hour. (Unit). There are no cheap or
off peak domestic rates.

Ours is a not untypical 1600 sq. foot (per main floor) all-electric
house, built some 40 years ago using 'two by four' wall framing etc.
Insulation and heat loss were not as well understood then by the
average carpenter etc. So this house is inevitably a 'bit leaky';
especially in this windy climate. However there are no rot or mould
problems as can occur in a too well sealed but imperfectly ventilated
structure.

If built today this house would be to R2000 standards with 'two by
six' thick walls, better insulation and well sealed vapour barriers
and therefore inevitably a heat recovery air exchanger system.

This four bedroom unit has an occasionally heated underground full
basement, and fully attached garage and store room.

Total energy costs are typically 12 x $208 = $2500/yr which includes
all sales taxes and the per month account charge of around $16 per
month, whether one uses any 'juice' or not.

The advantage 'To live better electrically', as it was advertised
then was quite a major decision to make back in the 1970s. When
electrcity supply was not as developed or as reliable!

Apart from simplicity advantages since them seem to have been similar
energy cost to fuel oil plus electricity. Much lower maintenance
costs; with no worries about cleaning or replacing combustion
chambers, cleaning or replacing deteriorated chimneys or vents, fire,
fuel tanks, fuel leakage, fuel delivery, gas leaks (piped in gas not
available here) etc.

Also individual room/area thermostats permit adjustment.

Total electrical heating repair costs since 1970 have been three wall
mounted (230 volt line) thermostats, one baseboard heater mounted
thermostat that got struck by something and one circuit breaker; a
total repair cost of less than $100. Electricity also very safe and
electrically heated home insurance premiums are very low.

Elsewhere; especially where electrcity is used for AC, not needed
here, we have heard cost can be up to 22 cents per unit.

Some homes have replaced fuel fired furnace hot water heating systems
with 'electric furnaces'. Retaining their existing radiators or hot
water baseboards. Energy costs said to be much the same and with no
fuel tanks or chimneys to worry about require less space. Zone
controls can often remain the same. Some newer homes have used
electric 'central heating' with underfloor piping for in-floor
heating.

Oil cost here (and gasoline) has been increasing; inevitably that will
and has affected the cost of some of our electrcity production because
not all of it, in winter anyway, does not come from hydro.

Info for comparison if of any interest.

On Apr 6, 9:17*pm, "Rob" wrote:
"blackhead" wrote in message

...

I used gas to heat a gas stove kettle with a cup of water in it to a
certain temp, and did the same thing for an electric kettle. Turns out
that gas now costs 30% more than electric using this crude test. Is it
now more economical to get electric central heating installed rather
than gas?

Thanks for your interest.

No, just don't go with British Gas or you will pay 100% more than everyone
with other companies. *Certainly for gas anyway, they are the most expensive
company about but stupid people still go with them.
Electric storage heaters are a waste of time and once the heat has gone
that's it. *So no turning them up a few times per day.
Change to a cheaper gas supplier, get your home insulated and get a new
boiler fitted. *You can get some work done under certain government schemes
if you are on some benefits or can't be bothered working. *Those who are not
afraid of working or can't think of a good enough excuse will have to foot
the bill.
The test you mention couldn't be measured in the home accurately anyway.

From that it sounds as though typical, cheaper rate, electricity
storage heaters must be large enough to store sufficient heat to carry
over from the cheap rate period (which I've read can be the six hours
after midnight to, say, 6.00AM?) through the times of day when
electricity is more expensive?
Seems like (In a typical home working day time shifts etc.) such
storage heaters would have to a) generate sufficient heat to at least
warm house to sufficient level for sleeping from around 11.00 PM to,
say 7 AM. And b) Also (and at same time) store sufficient heat for the
other two thirds of the day?
Is that how they are supposed to work?
Then there is amortizing the additional cost of the storage heaters?
In the same way that 'paying off' the cost of a heat pump system must
be considered inlight of energy savings?

"terry" wrote in message
...

If built today this house would be
to R2000 standards

The Canadians have the R2000 standard, which is one the most advanced in the
world, if not the most. The Canadians, say "build tight, ventilate right".
No air leaks.

The Canadians don't just slap up the vapour control barrier, as they do
here. It is meticulously installed and properly taped up. The Canadians are
implementing the R2000 standard in the UK and Japan. Canadian companies
have been involved with UK companies, as the UK companies just don't have
the skills levels, or can't concentrate long enough to carry out detailed
work, to make a house air-tight. R2000 done properly needs heat recovery and
vent system. This means always a constant stream of fresh air in the house,
keeping it fresh. They do provide a continuous stream of fresh air keep the
smell of house always nice, as odours don't have an opportunity to soak into
the building fabric giving out a permanent smell.

Follow the Canadian R2000 standard to the letter when building a house or
extension (increase the insulation levels if you want) and you can't go
wrong.

A typical heat recovery and vent system will have...
Flexible aluminium ducts, fully insulated. The incoming air through a 4
stage filter then via an electrostatic filter which will take out particles
at the micron level, smoke dust, pollen etc.

The cross flow non-contamination heat exchanger will have an electric
pre-heater or in-duct copper coil heater, heated via the boiler, if incoming
air too cold. Fans are variable speed low current devices.

An air conditioning unit (chiller), not big enough to provide full air-con,
but can drop incoming temp by several degrees and dehumidify the air, can be
incorporated easily if need be. Good house design will eliminate this need.

Having heat recovery and vent means ugly trickle vent windows are not needed
and draughts eliminated from these.

"Doctor Drivel" wrote in message
...

"dennis@home" wrote in message
...


"Rod" wrote in message
...
T i m wrote:
On Wed, 9 Apr 2008 00:10:08 +0100, "Doctor Drivel"
wrote:


External insulation, triple glazing and air-tightness will probably
drop that by half.

So, with all this air-tightness don't we suffocate? After we
hermetically seal the house we have to fit more air bricks?

Are there any 'domestic' Air-to-air heat exchangers that are actually
worth installing yet (both from their payback and functionality) and
from a d-i-y pov?

Technically domestic (because it is fitted to a house), the Grand
Designs house built into the ground up in the Lake District for a vet
and her family had one. (Reshown in extended form just a few weeks ago.)
The *claims* were that it is staggeringly efficient and wonderful...

But as to fitting it to an existing house, I doubt it.

Maybe http://www.wickes.co.uk/invt/156417 ?

That may be an a/c system rather than heat recovery ad vent. The
explanation is poor.

Looks to do both.