used 56 MCF in 28 days

jp_2

buy a smaller house

Jim_152

used 58 MCF in 28 days

Just wondering if this is normal. I have a 1929 English Tudor in West Akron Ohio (4200 sq, ft,) all brick exterior. Have a Moaut two pipe system, 500k BTU boiler. Have a great steam expert to service this. Installed a low burner set-up, so when my furthest main reaches 155F. low burner kicks in. Also installed meter to measure gas pressure. High burner runs at 3.1, then low burner drops to 2.0-2.1, when temp hits 155F at furthest main. Have replaced 13 of 34 single pane glass windows, with double pane/argon windows. Replaced almost all steam traps. Other steam traps seem to be ok, based on out-going temp. (10 degreee difference) All out-going steam pipes are insulated. No return pipes are insulated. Attic has 6-8 inches of blown-in insulation. (yes I need to add more) I had an insulation company come in, and they drilled a hole in my downstairs wall, and there was blown-in insulation in the wall. Did not have any more walls drilled, to see if they were also insulated, because I felt if one was, they most likely all were?? Boiler water is clean, just had boiler clean this fall. Sight glass is always clean. Gorton vents installed this fall (about six in total) At 12-15 dollars per MCF this winter, I'm looking at a $700 gas bill coming up. Is this amount normal to all those folks out there, that have a similar scenario? I can certainly put more data into this message, but afraid I may not get anyone to read, if this is too long.
Thanks for any comments

Steve Garson_2

What is your day and nightime temperature?

With only 6-inches of insulation in the attics, there's a lot of heat going out the roof.

Steve

Jim_152

High MCF consumption

Steve,
Thanks for the response. I have been recording my high temp and low temp on an excel spreadsheet, along with daily gas useage, basically the high temps have been 40 max. (only about two days) and low as 1. Average temp. for this time period has been about 22. I was told, that my biggest bang for the buck was to replace my original casement single pane glass windows. The rooms that the new windows are in, are warmer than those that I have not replaced yet, so I beleive this has helped. I have invested 12K thus far this year, between my steam system upgrades and window replacements.

Steve Garson_2

What is your inside T-stat setting during day and night set-back

Brad White

Back of the Napkin Analysis

Your 500 MBH boiler certainly seems over-sized, certainly in that you have some insulation now. Houses of that type as-is originally, I could see with a heat loss density of about 50-60 BTUH per SF in your climate (6300 DD and a -1F design OD Temperature). Your boiler by net output could handle a house with a loss density of 190- a factor of nearly three. All of that cycling has to take a toll on efficiency for sure.

At 4200 SF and those numbers, I could see an original heat loss of 210 MBH to 252 MBH.

I figure the radiator EDR might be in the range of, oh, 300 MBH worth, allowing some open windows. Call it 1,250 EDR. Your boiler if we add 33% to that and assume 80% efficiency at combustion, could justify a 500 MBH input boiler, so that works. Fair guess anyway.


With insulation as you describe plus new windows, I can see this dropping to maybe 40 BTUH per SF, more or less. Call the heat loss 170 MBH at this point, just a wild guess.

I extrapolated the degree-days for Akron (USAF Weather Data PDF attached), and figured an average not actual DD passage of about 830 over the past 28 days. Could be up or down 15% but bear with me.

If the heat loss is now 170 MBH but your over-sized plant efficiency is say, 65% and we had 830 Degree-Days and you keep your house at say 68F indoors, I get a usage of about 460 therms or 45,970 CF in rough numbers.

If you burned 58,000 in the same period, you would have either a larger heat loss by 26%, or greater degree-days by a similar margin, or a lesser efficiency by a similar margin.

Anyway, just a ballpark comparison. You are high but only by my remote estimate. You have the reality and it is in range at least. Now let's figure which variable needs tightening.

jp_2

time to do

an entire house heatloss, look under resources above.

Jim_152

T-Stat setting

My T-Stat is set at 68, from 5:00 p.m. until 10:00 p.m, then drops to 62, until 5:00 a.m. Back to 68 until 7:oo a.m. then back to 62 until 5:00 p.m. I also have played games on leaving my T-Stat alone at 68 for two- three days at a time, and frankly there is not a whole lot of difference in MCF useage when I do that. The house recovers quikley, meaning that, I can come home from a business trip, where my T-Stat is set at 62, turn up tp 68, and within one hour, the house is at 68. I can shut this off, when temp is at 68, and will wake up at 6:00 a.m. and the house is at 63 (nightime temp. is say 20) I'm beginnning to wonder if moving the temp up, and down makes any sense, relating to gas useage, as I do not see much difference

Jim_152

time to do

JP,

Thanks, your a genious, I never thought about asking for advice. I would not be wasting my time on this site, if I knew as much as you, or anyone else.

Steve Garson_2

I would keep doing the set-back.

Do you have usage numbers for last year (warmer)?

As posted earlier, a heat loss calculation is the right thing to do. You have a big house and I suspect that you should get more attic insulation.

But a heat loss calculation will help put things in perspective.

Dick_2

What pressure settings are being used to control the operation of the boiler? Your system should be operating using ounces of pressure.

Chas_2

over sized boiler

Sounds like a over sized boiler 500,btus for a 4200 sq ft house that's about 110 btu's per sq ft that's over sized,as for set back i've found that in some cases there is no savings for wide set back espically with steam systems that have alot of piping and large pick up factors ,all that engerny that's put into the systems to heat the mains is lost as you go into long deep set backs ,are all your mains insulated and in closing as my dada says big house big bills and actually 700 bucks for a home that size is not bad at all ,with all the improvement you have done did you except too pay only 300 to 400 then you should move into a smaller home peace and good luck clammy

tim smith

re useage

My house I think is of similar construction w/ same upgrades. We don't hit design temps like you or even avg temps near yours. If we were at avg temp of 22 for a month, my heating & dhw gas bill would be easily 450.00-500.00 month. I have appx 1500 sft less of a house and scorched air w/ high efficiency furnace. Not direct comparison but think #s not too far off?? Yes I have scorched air that is existing and hate it, but oh well, no time to change now.

Dick_2

Call Gerry Gill(look under find a professional); his partner has a Mouat system and they love steam!