"js.b1" wrote:

The problem with a flueless gas fire is...
- Ventilation requirements likely exceed the heat output capability

I'm not understanding this. Maybe it is our 'common language'. Is
'flueless' the same as 'ventless'? In the US a ventless has no
requirement for outside air.

- Water output is high, not unlike an LPG bottle radiant heater

My 30K BTU heater has never steamed up any windows. A pot of
spaghetti on the stove puts out more moisture.

For me, the moisture that is added by an LPG fire is welcome- as it is
a struggle to keep the humdity as high as 38 in my NE US winters.


In the UK there are Balanced Flue flame effect fires.
- These simply require an outside wall
- Drill a hole, fit a coaxial flue
- Air pulled in from outside, combustion products out

A ventless fire- there are wall heaters and freestanding stoves, as
well as 'logs' that go in fireplaces- in the US just needs a gas line
run to it. Combustion air is provided by the natural infiltration
that all houses have. There is a safety switch that should turn
the gas off is there is not enough oxygen for combustion.


It would be interesting to compare a flueless gas fire efficiency
(with BG 10x10cm free air flow vent) to an electric version. Gas is
abour 3p, Electric peak is about 10p (UK).

This year- my ventless is slightly more expensive than electric. [but
cheaper than my oil by about 25%] Up until a couple years ago it
was cheaper than the electric.

I used 100% efficiency for electric and my ventless propane-- and 75 %
for my oil furnace. It tests at 85% at the flue, and I allow for a
bit lost in the ducts.

I recall Gas Inset DFE Fires can be below 35% efficient and any heat
up the open flue will draw more cold air through the house so are
probably 25-20% efficient in most cases. That means they are as or
more expensive than an "Electric DFE" - better to get an oil radiator
or fan heater and a TFT panel with flickering fire video looping on it.

Although we both seem to have a different idea of ventless/flueless -
we both agree that anything with a chimney in a living area is a
losing proposition.

Jim