AHS S130 : Coal Consumption During Summer Months?

If you have been firing your AHS S130 year round in order to supply DHW during the non-heating season, how much coal does it eat per day (or per month) when it is idling along doing nothing but providing the homes hot water needs?

And if you shut your AHS S130 down for the summer months, is it because of coal consumption that is too high to make heating DHW year round economical?

lsayre wrote:If you have been firing your AHS S130 year round in order to supply DHW during the non-heating season, how much coal does it eat per day (or per month) when it is idling along doing nothing but providing the homes hot water needs?

I ran my AHS throughout the summer two years ago. Last year I continued utilizing coal until I ran out and then I turned on the oil and cleaned out the AHS 130.

My coal consumption per day was about 40 lbs and so a hopper load could go about a week (300 pound hopper?) though ashes needed to be rmoved every three days or so. If I knew what I think I know now I probably woud turn the dump temp down to 130F from 140F on the thermocoupler and probably get better yield. Pea anthracite costs me about 8 cents a pound delivered. That means the average month for domestic hot water is $99.00. That is still cheaper than oil by a factor of at least two. During the winter the factor is 5X as the AHS burns much more efficiently.

Some advantages to running in the summer ( and I have never had the fire die on me even with 100F temps outside and I don't have a dump valve) is financial savings, less corrosion on the ductwork and the boiler than if they were down... even if cleaned and brushed.

The only downside for me is that the smoldering coals can occasionally produce some SO2 and the summer breezes can carry that towards one of my neighbors (though it doesn't happen that often). But burning coal is still not illegal and I do my best to make sure conditions are optimal for me and my neighbors.

Hope this helps a little.

Stephen

Thank you! How little coal can the AHS S130 consume daily and still remain firing reliably? Can it remain firing on as little as 10-15 lbs. per day?

lsayre wrote:Thank you! How little coal can the AHS S130 consume daily and still remain firing reliably? Can it remain firing on as little as 10-15 lbs. per day?

I don't know whether or not 10-15 pounds per day is feasable. I say that because I do not know whether or not there is enough thermal mass to continue keeping heating output going throughout the day. Perhaps it could be done with less than forty pounds per day, but I don't think by more than 10 pounds less.

Stephen

Gosh, don't quote me as I can't remember where I read this or heard it, but I had it in my head that 18 pounds a day was the minimum just to keep an AHS130 going. Obviously if you have three teenage girls taking showers twice a day your usage will vary.

It's becoming quite clear that I might as well just heat my DHW with my electric hot water tank during the late spring/summer/early fall months.

Anthracite will cost me about $235/ton delivered where I live, and I'm paying 6.6 cents/KWH for electricity. I've done numerous calculations, and I've narrowed it down to where my current cost for electric DHW (when isolated from all other electrical uses) is between $28 and $33 per month. If it will rquire that I burn 50-60 lbs. coal per day just to idle it and provide DHW, then it looks like running the AHS S130 during these months simply to heat my DHW could cost me as much as 5 to 6 times what electricity is curretly costing me per month for that purpose.

Contra to this, it looks like I should be saving roughly about 45% on my heat bills during the home heating season. And if the electric company ever does away with my special electiicity rate and hikes me up to the current Ohio average of 11.2 cents/KWH, then heating with coal will offer substantially better than 45% savings.

Even at 11.2 cents/KWH it does not appear worth it to attemp firing the S130 year round merely to provide DHW in the warmer months.

The amount of coal required to produce domestic hot water during the summer largely depends on two things.

1. The frequency and duration of timer cycles required to keep the fire alive and happy.
2. The amount of domestic hot water you use.

I would estimate about 15-20 lbs per day to keep the boiler running, but your mileage may vary.

Before you write off summer use of the S130, consider that year-round burning will extend the life of the boiler, and keep your stovepipe looking like new. If your basement is the least bit damp, you will have to do a very good job prepping the boiler to prevent corrosion while it is sitting idle. On the flip side, running the boiler will keep the basement dry...

I have an EFM, but I fully intend to run it through the summer for the reasons above.

-Rob

markviii, those are points well taken. I do have a dampness problem, so if I can run it on as little as 15-20 lbs/day it sounds like the way to go just to prevent rusting and corrosion. Thanks for this advice.

My .02 says that it is easier to maintain fire through the summer and keep the basement dry and the boiler is excellent shape. The cost cannot be that much different than the electric water heater, and your investment in the boiler and piping will certainly pay back over a short time. If oil remains in the $3.00 range, you will be in a two or 3 year payback......what other heating equipment will do that for you and your family?
You will probably shut down for a few days during a non critical time to clean and service the boiler, anyway.
Be aware that you can include your electric water heater in the domestic coil loop if you chose, so that it doesn't sit idle all the time. A bronze circ is required for all potable water connections.....think about that possibility.
My take on the daily usage would be in the 25 to 35 lbs a day average....some heat on a few cold days, and standard hot water usage. You won't have any out-fires in my experience, and ash container changes every 4th day give or take.
Many folks shut down in late March or early April, and there are still lots of cold days, so having the boiler online eliminates a more expensive fuel to chase the chills away, simply keep it loaded and empty the ash container.....

To break even vs. electricity for my summer DHW needs I need to get coal consumption down to 9 - 10 lbs./day. Anything above that is lost money, and would only benefit in keeping the S130 from rusting. At about 20 lbs. coal/day it will penalize me about $40 per month in extra expense over and above electricity to run it during the summer as a rust prevention measure.

I understand the situation, and it becomes a personal choice, however if the stove pipe and baro rust up, you will be out some cash anyway, and it the boiler is not cleaned and treated, the shorter life expectancy of the equipment has to weigh in. It is more than saving every cent.....you aren't an accountant are you???

It could become a 'Penny wise and pound foolish' issue. I'm not saying it would, but it sure could. I'll bet Toyota wishes they had used a more rust resistant steel in the pickup frames.....

Either way it will work, I'm just trying to extend the life of the system; they are expensive enough the first time!

Six cents for electricity?? Wow... We're paying A few tenths under eighteen cent a KWH!

Last year I was paying only 4.5 cents per KWH. At that level coal hardly made sense at all in this area. With the jump to 6.6 cents/KWH coal is going to save me. The Ohio average as of the latest figures I could find (for September of 2010) was 11.2 cents/KWH. I live in an area where natural gas is not available and there are many all electric homes. Due to this situation the electric company offered a super special deal years ago where I live, and now they would like the deal to go away, but the 'PUCO' will only let them bring it up incrementally. The first increment was 4.5 cents to 6.6 cents.

My electric hwh cost close to $50/month. I did not try heating last summer, this year I will. From Oct. to April I use about 6 tons to heat and my domestic water. If your boiler is located in the basement, this will also help eliminate the dampness and mold growth. For a year of heating domestic $50/ month = $600, I can buy 4 tons with that.