Oil Usage two pipe steam system

Roma

I have a 2700 square foot tudor home and I live in the new york area.  I keep my heat set at 68 day and night.  The house is not insulated well as it was built in 1936.  Does 1200 gallons a year sound excessive?  I also have a boilermate that is connected to the boiler for hot water consumption. 

Jamie Hall

Maybe a tad hign...

but it really doesn't sound excessive for a building like yours.  "Not insulated well" is probably a drastic understatement!  The first thing to do though is to go looking for infiltration -- windows, doors -- and fix it.  Depending on a whole slew of factors, the best bet might be really good storm windows and doors (replacement windows are, despite all the hype, rarely cost-effective).

Roma

Oil usage

I actually have replaced all the windows about 3 years ago (45 of them) including the basement windows.  I also have an amtrol boilermaker for water that runs off the boiler for hot water all year.

Mark N

How Old?

How old is your boiler? Is it from1936. How much radiation do you have? Is the boiler sized properly? Has the boiler been maintained for best efficiency? The price of oil is now well above $3 a gallon. I would be looking to cut consumption while maintaining comfort.

Roma

boiler info

The boiler is a peerless and it is from 1992 or 1993.  I have an oil company come in and clean it every year.  I have 21 trane convector boxes throughout the home.  I just recently increased the venting on the mains which really seems to be bringing the heat up to the convectors in about half the time.  I know I have to change the steam traps again since some of them seem to be failed in the open position.

turbobike

oil usage

My home was built in the '30's, with little insulation. Previous owner put on insulated aluminum siding, and insulated the attic. We have about 1800 sq ft. Boiler was replaced about 10 yrs ago with a Weil-Mclain. I replaced all steam traps this past summer (they had never been replaced in the 30+ yrs I have been here). Heat seems to be more even since I replaced the traps. I keep the thermostat at 68-70 degrees. (We're old-we like it warm!) Hot water supply is off the boiler as is a 6 ft hot water baseboard unit for the rec room. We normally use about 1000 gallons of oil per seaspn, altho it looks like it will be more this year. .

Roma

okay

So I guess my 1200 gallons a year isn't all that bad?

BobC

Questions

Did you increase the mains venting just this season? You said that decreased the amount of time to get steam into the radiators by about half and you still have to check some steam traps. Between those two I would think you should see a nice drop in fuel usage.



What pressure is the boiler running, it should be below 1.5PSI max. You might have to install a low pressure gauge because the 0-30's are not very good down that low. Also do you know how many sq ft of convectors you have verses the number of sq ft the boiler is rated for?



Is all the piping in the basement insulated? If not your burning fuel to heat that basement.



Bob

Roma

Main venting

I just upgraded the venting about two weeks ago.  I also had my asbestos abated and added 1.5 and 2" thick insulation on all the pipes except the header and some of the fittings.  However some of the fittings are covered with zeston insulated covers.  I still have to do the steam traps.  The system is running on about 3/4 of a psi (that the setting on the vaporstat).  I am not sure as to how much sq ft of convectors I have versus the rating on the boiler.  I do have a chart for trane convectors and I guess I could figure it out.  I am not sure how I would be able to find the rating on the boiler though.  Since it was here before I moved in.  It is a peerless and it is something and the number 5.  I am at work right now and will have to double check that.

BobC

Should be improved

Last year i put an elapsed time meter on my oil burner so I could easily track oil usage. Knowing the fuel usage and the degree day data can give you an accurate idea of how well the system is working and let you accurately judge how well any improvements you make to the system are working.



I suspect your improvements will make a nice dent in your fuel usage.



Bob

Brad White

Not too bad

but like anything else it could be better.



From your 1200 gallons I back-calculated an approximate heat loss of 91,000 Btus per hour (BTUH). My basis is a 5,000 degree days,  8 degrees F. design outdoor temperature, 65% efficiency and oil at 140 MBH per gallon.  I also used a 0.60 Cd factor (an admitted fudge factor to account for internal gains, thermal storage and passive solar gains).



At 91 MBH and 2700 SF that is 33.7 BTUH per SF, which is not too bad for an uninsulated or partially insulated house. You might get that down to 25 with some diligence.



I did not even count for DHW use, that could be worth 200 to 250 gallons of your annual bill. So if "heating only" is apportioned to 1,000 gallons, that is respectable or rather, not out of the ordinary. A good place to start for improvement.

Brad White

Good idea

I like the elapsed time meter concept but would caution that if you have pre and post firing purge cycles, that can add a minute of electrical draw but without fuel burning,  to each cycle. Not much but it adds up and it is better than nothing.  But yes, coupled with HDD data, it is a good finger on the pulse and establishes a "weather normalized baseline" so you know when you depart from that.



I use a Type K thermistor and a data logger and monitor the flue temperatures from initial spike (up-trend) to the peak and first drop off.  I just spot check and do not log this chronically, but I probably should. To me it is just a short term diagnostic tool but it would be a nice feature on an "energy dashboard".



My $0.02 anyway.



Brad

BobC

No delay for me

Luckily my Becket AFG has no delay - especially after I put in the new Ignition transformer (original was almost 15 yrs old) . I sought out the transformer because i really don't trust the electronic igniters (I used to design them and i know what can go wrong - ESPECIALLY after the accountants go over the bill of materials).



Bob