i have a 85 year old 4000 sq. foot masonary with no insulation in the
walls and insulation blown into the attic. the windows are old. my
boiler is an oil fired weil mclane from the early 70's rated for 1500
ft of steam. i have been burning about 3500 gallons a year in
northeastern PA. i'm trying to figure out if there is something wrong
with my boiler or vents etc. i know my house could be better insulated
but, given the current insulation situation is 3500 gallons a
reasonable amount of oil to burn? Could heat be escaping somewhere in
pipes, vents? i have asked professionals to look at my boiler and have
received several answers. most have not spent much time really
examining my steam system. some say it should be replaced, some say it
is fine and the issue is insulation related. any ideas?
For the size, age, and condition of the house, 3500 gallons is not
unreasonable. I'd start looking at things like new windows, adding
insulation, sealing up any possible leaks. I don't know what the interior
walls are like, but I'd certainly look at insulating them somehow. You can
probably shave 25% to 50% of the oil usage. Better to put that $2000 a year
savings into improving the house and your comfort instead of just buying
If the burner is operating properly, it may be close to efficiency of some
of the newer units and that is not going to save much. The old Wild McLanes
are still a pretty good boiler.
Thee are a few ways, depending on how much you want to invest.
Some utility companies offer low or no cost energy audits. They will
inspect and make recommendations. Some private firms offer more extensive
testing and take thermographic photos, put wind machines in the door to find
leaks, etc. This runs into hundreds of dollars. Start with some research
and common sense by caulking, sealing, adding insulation where possible,
check windows for drafts, etc.
Seal up the entire house and get new doors and windows. This includes the
basement and attic. Talk to an insulation contractor about spray foam in the
walls. It won't be cheap, but the savings can be great. Spray foam in walls
is better than blown in insulation because it doesn't settle.
If the boiler has been using about the same amount of oil for many years
now, then the problem probably is not the boiler. If you have steam leaks,
then get them fixed. Before you replace the boiler, look into a new flame
retention burner, and make sure the heater is cleaned every year. Before you
install a new steam boiler, look into changing to hot water. Two pipe steam
is easily changed to hot water, but one pipe steam can be difficult and
costly to change to hot water. If you decide on a new steam boiler, find
someone who has experience on steam. The new steam boilers tend to hold less
water, and certain provisions must be made for this.
My father in-law has a house in Maryland (not as cold as your area) that is
1800 square feet and he goes through aboit 1000 gallons during the winter,
so your consumption sounds about right. Probably nothing wrong with the
system. Sounds like you are heating the surrounding real estate.
Follow some of the suggestions from Bob and Ed and you could probably knock
off quite a bit of that oil usage.
Or you could move to Florida...
You boiler is probably 70-80% efficent on steady state running but
overall 60% efficient, there are 95% efficient condensing boilers out,
you could save 40% with a new unit, 10-25% with top line windows, and
depending on how much insulation you can shove in 5-40%. I heat 1800sq
ft zone 5 to -15f, last years yearly Ng was 465$, and everything is Ng.
You have alot of room to improve but it costs to do it.
I just googled condensing oil boilers and saw a few. I did not research
them closely, a system 2000 is up to 87%, HW boilers definatly go to
98-99% with 96% being easily found, Steam is another issue altogether.
Operating temp vs efficiency on modulating boilers varies max
efficiency, being at lower water temps on some units. Point is there
are alot of ways to save, and my several boiler guys always recommend
whats easy for them and what they sell, not what I want or need, Today
and the future supply of Ng are going to to stay tight with high prices
since no real new drilling is going on, Soon we will be importing more
LNG because of dam invironmentalists blocking drilling we all are paying
out the ass. Anwar is the lastest loss to large reserves, and Im never
going there to see it, its to dam cold there. These high and higher Ng
prices are here to stay.
You're technician told you the 'steady state efficiency'. He's talking about
'seasonal efficiency". Older boilers have more standby loss when they're not
running. You can save money by installing an automatic vent damper which
stops natural draft from sending heat up your chimney when it isn't running.
Could well mean 74% while burner is lit. If duty-cycle (% of time
firing) is low, much heat that's been absorbed by innards of furnace
(making it literally glow) is sucked up the stack by convection. This
is the selling-point for automatic stack-damper.
But 99% oil-fired boiler? I'm from Missouri on that, Rans. 85% while
There is the afue rating, the boilers design efficiency, most old units
are 70-80% and this to measure is extremely difficult to do as gas
consumption has to be measured, among many other parameters, so people
guess by knowing the design, your tech measured burner efficiency not
overall system. There is design heat loss and time to heat to steam
figures that come into it. New boilers are smaller ,smaller boilers
heat smaller amounts of water so less fuel is waisted up the chimney. An
example is Ng tankless water heaters,[and many can be used as
boilerslike the Takagi TH1] have an efficiency of 94% but have an Energy
Factor of 92% where as the best Sears Ng HW tank has an Energy factor of
63 for Ng. Same theory for boilers, Your burner may rate tested 95% but
overall efficiency could be 50%, So you could save 50% by upgrading if
you know what you are looking for. Problem is salesman sell what they
have and know, so now you have Google.
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