Figuring my increased efficiency-gas fired steam

PS_3

In that case I went from ~ 4.1 to 7.4 HDD/therms (annual), and that includes adding 2 more radiators (HW)and replacing the tankless coil with an indirect. No cooking, etc.

That you increased your gas consumption efficiency 27% with an upgrade to an existing steam system is a tribute to your installer, and your overall numbers show that steam can be competitive with a hot water system.

Now if I can upgrade my envelope without breaking the bank, I'll be able to further maximize my mod con's efficiencies.

Dave Miller_2

Been having fun

looking up the Heating Degree Days (HDD's) and the usage history from the Gas Co. (National Grid(lock) and comparing the old days before steam boiler replacement and then before/after whole house insulation.

We had circa 1930 gas conversion from coal Boynton which was replaced with a Utica PEG 112 connected to a 275 sq ft EDR load (7 old column rads). That seems to have increased our "efficiency" from 3.85 Therms/HDD to 5.28 or about 27%.

Then, last Feb/Mar we had the pros come in with a full insulation package for our 1930 2 story which included the attic, walls (dense pack cellulose) and the basement above grade. Boy, we should have done that years ago, 'cause our Therms/HDD now looks like it could run around 8.5. That's another "efficiency" increase of 38% (if my math is right). By the way, we are also heating the kitchen and an addition with a gas fired stove so all these therms are not used for steam. We cook with gas but heat water electrically.

So, if you want to do this exercise, I'm getting the historical HDD info from:

http://www.erh.noaa.gov/bgm/climate/syr.shtml

where erh is eastern regional HQ for NOAA, bgm is Binghamton NY Forecast office, climate is where the data is and syr is the Syracuse weather station. I am parsing the URL 'cause you will have a tough time getting your local HDD's without structuring a similar locator. You will need to know your nearest forecast center and local weather station by going to noaa.gov and keying in your city/state in the forecast box on left. This will give you the NOAA forecast center and local station.

Once you get to the proper page, just below the current chart you will see month/year selection boxes for the last 10 yrs climate data. Select a month and look at column 6a for HDD by day and totals at the bottom. Marry that data with your gas co. usage history from their web site (or your old bills) Note the NOAA data is for a calendar month and the gas co is by meter date for the prior month. Obviously this could be used for oil consumption as well..........

Sorry to ramble on and would be curious whether anyone has similar data they want to share.

Happy Holidays to all..................!!

Dave Miller, HO
Skaneateles, NY (still snowing)

PS_3

Dave,

Maybe I'm missing something but there seems to be a problem with your numbers. First - Your values (Therms/HDD) should decrease after an improvement - not increase. Second - I hope the values you posted are actually BTU/SqFT/HDD, otherwise they orders of magnitude too high.

Congrats on your energy conservation improvements. I upgraded my boiler 3 yrs ago and have realized ~ 44% savings in gas consumption (from 16.0 to 8.9 Btu/SqFT/HDD). I would love to add dense pack to my walls - but I have vinyl siding over fiber board over wood shingles on the exterior and 1" rock plaster with metal lathe on the interior - not an easy upgrade.

Dave Miller_2

ps you are correct

to question my numbers as I meant to say HDD per Therm. I'm simply looking at consumption in therms and the total HDD's for the heating season. By dividing the HDD total by the total therms used, my increase in efficiency is measured in more HDD's per therm.

The point I was trying to make is that the insulation project is by far the bigger bang for the buck than the boiler replacement, especially as they each cost about the same.

Sounds like it would quite a challenge for your walls, but doable. Our contractor simple removed a couple of clapboards and drilled holes (2"maybe) in the sheathing to pump in the cellulose into our wood lath/plaster covered stud bays. Seems like they could do the same on yours.................?