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Tony Hwang

wrote:
On Sep 12, 8:27�am, terry wrote:
On Sep 12, 10:01�am, "JohnR66" wrote:

I heard that adjusting the gas valve on my standard natural gas furnace will
make it more efficient.
By partially closing the gas valve reduces the flame. Although the furnace
would run longer, the flue temp is reduced meaning lower heat loss and
improvement in efficiency.
An analogy is like driving a car the same distance once fast and once slow.
When driving slower, it obviously will take longer, the engine is on longer,
yet fuel usage is less.
I have no way to verify if this is BS or not.
Yup and while not a 'gas man' turning it down might risk the furnace
not coming on when it should. And why would running the furnace slower
save fuel anyway?

Just suppose you were to run hot water into a pail on a cool day.
Inevitably the pail would lose a little bit of heat while you were
filling it; maybe taking a minute or so to fill the pail with hot
water, right?

Then suppose you were to set the tap to very low or even just a drip
of hot water every second or so?

At the end of maybe an hour the pail might be partially filled and the
water would have lost it's heat anyway.

After all it's heat you are trying to make, to heat the house!

A certain amount of gas or oil or wood etc. can be burned to make a
certain amount heat (depending on the efficiency of the furnace etc.)
hard to see that fiddling around with the gas/oil supply would make
the furnace any more efficient. In fact maybe make it unsafe!

It also used to be said that for a furnace/heating system to be most
effective it should be just big enough and be adjusted so that it runs
almost continuously (i.e. at highest efficiency cos it's not cycling
and cutting in and out heating up and cooling down as often), during
the coldest weather.

Don't think the car analogy is good one.

my best friend throttled his back last winter, and had no troubles.

wouldnt recommend this for a direct vent 90+ type.

his furnace would occasionally gop boom on start up, throttled back it
didnt but ran longer.

he cleaned the burners this summer they were clogged near pilot light,
no more boom explosions
Hi,
Your friend is an IDIOT!