Hypothetical Q - reconnecting to balanced flue
 

SWMBO wants to move house, and has found a really nice one she likes
the look of. It appears to have been 'done up' really well, although
it has downlighters everywhere - nine in the conservatory alone
(gasp).

The question concerns the fire in the lounge - it currently has an
electric 'contemporary' fire, but goes on to say 'Gas point and
balanced flue still installed if needed'. I like the idea of a 'living
flame' gas fire rather than an electric one, but would it be
acceptable, and possible, to fit such a fire using the balanced flue,
or would some new BR or Elfin Safety intrude here at great expense?

TIA

Hypothetical Q - reconnecting to balanced flue
 

In article ,
Terry Fields writes:

SWMBO wants to move house, and has found a really nice one she likes
the look of. It appears to have been 'done up' really well, although
it has downlighters everywhere - nine in the conservatory alone
(gasp).

The question concerns the fire in the lounge - it currently has an
electric 'contemporary' fire, but goes on to say 'Gas point and
balanced flue still installed if needed'. I like the idea of a 'living
flame' gas fire rather than an electric one, but would it be
acceptable, and possible, to fit such a fire using the balanced flue,
or would some new BR or Elfin Safety intrude here at great expense?

"balanced flue still installed if needed" doesn't make any sense;
a balanced flue is part of an appliance, and comes with it.
If they left an old flue behind, it won't be any use.

There were balanced flue flame gas fires (haven't looked in a decade
now). They have the flames behind a glass front, sealed from the room.
Like any decorative real flame gas fire, they're horribly inefficient.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Hypothetical Q - reconnecting to balanced flue
 

Terry Fields wrote:

The question concerns the fire in the lounge - it currently has an
electric 'contemporary' fire, but goes on to say 'Gas point and
balanced flue still installed if needed'. I like the idea of a 'living
flame' gas fire rather than an electric one, but would it be
acceptable, and possible, to fit such a fire using the balanced flue,
or would some new BR or Elfin Safety intrude here at great expense?

There could be another reason why they took the gas fire out. I know we
replaced our gas fire with an electric one as it was the only way we could
finally sort the problem of a freezing cold draught coming into the living
room via the chimney flue. I have known of people suffering cold draught
problems with balanced flue gas fires also.

Also, although electric fires cost more to run, they are 100% efficient,
whereas gas fires are nowhere near that. We only use ours a handul of times
each year, so the cost of running is negligible.

Hypothetical Q - reconnecting to balanced flue
 

Davey wrote:

There could be another reason why they took the gas fire out. I know we
replaced our gas fire with an electric one as it was the only way we could
finally sort the problem of a freezing cold draught coming into the living
room via the chimney flue. I have known of people suffering cold draught
problems with balanced flue gas fires also.


But a balanced flue that allowed a freezing cold draught into the room
would be rather badly installed. Wouldn't it?

--
Rod

Hypothetical Q - reconnecting to balanced flue
 

Rod wrote:
Davey wrote:

There could be another reason why they took the gas fire out. I know
we replaced our gas fire with an electric one as it was the only way
we could finally sort the problem of a freezing cold draught coming
into the living room via the chimney flue. I have known of people
suffering cold draught problems with balanced flue gas fires also.


But a balanced flue that allowed a freezing cold draught into the room
would be rather badly installed. Wouldn't it?

With the prevailing wind blowing directly at the flue it brought in a cold
draught. That's what I was told and there's no reason for the bloke to have
lied.

Hypothetical Q - reconnecting to balanced flue
 

A balanced flue is *room sealed*, that is the whole point.

Balanced flue has inner & outer tube, IIRC...
- Inner allows air to enter for combustion ONLY
- Outer allows heated combustion products out ONLY

The only draught would be room convective draught caused by air
flowing over the heat exchanger.


Class-1 chimney gas fire is conversely very different.
- Some are only 45-55% efficient (some go 72%+)
- Thus 28-55% of their heat goes up the chimney
- Air is drawn through through the house via house vents
- Thus they can cause a howling draught under a door

The most common cause of a howling draught is a full bore chimney pot
without rain guard, being sucked by the prevailing wind, combined with
the huge thermal mass of the chimney length. That draught can spin a
newspaper from front to back without difficulty if placed near a
doorway and reduces efficiency yet further - it is how a gas fire can
"suck a house cold".

The often forgotten trick with open hearth fires or gas fires when out
is that they STILL suck air all night long, that thermal mass &
prevailing wind can combine to "suck the house cold". Stick a sausage
outside the relevent door when going to bed, you may find the house is
significantly warmer.

This is why some people end up with Class-1 flame-effect or gas-fires
AND central heating which "fight one another", the central heating is
having to preheat the air so as to avoid draughts which vanish up the
chimney. A door sausage can save £50/yr and avoid such problems - BUT
there must still be sufficient air for combustion (just some chimney
draw like an 9" square extractor on maximum without a fire).

So any "draught" was due to convective effects across the balanced
flue fire's heat exchanger, or it was a class-1 flue type fire (using
chimney).