Coal Usage Questions

Carbon12 · Post by **Carbon12** » Mon. Dec. 09, 2013 8:55 pm

So at 50 pounds a day that's say 2 pounds and hour or about 26,000 BTU's per hour. Assuming 80% efficiency, you're heating the house and garage for about 21,000 BTU's/ hour. That sounds AWSOME to me. What was the original heating appliance rated at, 100,000 BTU's/ hour or more??? Someone didn't do the math right if that's the case!

lsayre · Post by **lsayre** » Mon. Dec. 09, 2013 9:38 pm

But if the mean daily temp is currently averaging only 35 degrees right now, which equals 30 HDD's, then 45 lbs per day is only 1.5 lbs per HDD.

If the design temp of the home is -20, which is 85 HDD's, then 1.5 x 85 = 127.5 lbs. of coal for that -20 degree design day. That requires about 70,000 BTU's per hour. Toss in DHW demand on that day and 100,000 BTU's per hour sounds about right.

Carbon12 · Post by **Carbon12** » Mon. Dec. 09, 2013 10:02 pm

Yupper doodles. Point was 2 pounds of coal an hour is pretty good for that sized boiler and current heating load.

Post by **Lightning** » Tue. Dec. 10, 2013 3:44 am

Rigar wrote:Im heating nearly 4000 sq ft when you consider the basement...and do so with 4 to 5 ton a year.

Wow... I use that much for 2400 sq ft.. Whats yer secret??

Rigar · Post by **Rigar** » Tue. Dec. 10, 2013 6:00 am

Lightning wrote:
Rigar wrote:Im heating nearly 4000 sq ft when you consider the basement...and do so with 4 to 5 ton a year.
Wow... I use that much for 2400 sq ft.. Whats yer secret??

...we keep the house at 58 degrees !!

Post by **Lightning** » Tue. Dec. 10, 2013 6:03 am

I don't believe ya hahaha

Rigar · Post by **Rigar** » Tue. Dec. 10, 2013 6:15 am

....no secret really.
..the house was built in 1890...but I did a COMPLETE gut job on it in 2011...
even replaced 2/3 of the foundation.
Completely new electrical , plumbing , windows etc.
you name it-it got it.
It started out as a flip....but we feel in love with the potential this old barn had!.
Most of the upstairs ceilings are closed cell foam...as is the vaulted ceiling in the kitchen.
Every interior wall and floor is insulated as well
....but I think the biggest factor when it comes to heating is its "open" floor plan and proper ductwork...etc
....we do only keepit 68 -70 or so (according to T-stat)
...70 feels a bit stuffy tho...as we are usually keeping pretty busy here.
I was fortunate to have the luxury of building the heating system to fit the house as well....(wish a boiler was in our budget then !!!)

oliver power · Post by **oliver power** » Tue. Dec. 10, 2013 6:31 am

coalkirk wrote:Your usage doesn't sound bad bad. I guess I wonder why such a big boiler for 1800 sq. ft.?

I wondered the same thing. Maybe future buildings......... I'm heating 1700 square feet with Kaa-2, on top of windy hill. I go through 5 ton for heating season. Keeping house at 73*. When I heated the house with HITZER 50-93, I went through 5-1/2 - 6 ton, depending on winter.

Post by **Rob R.** » Tue. Dec. 10, 2013 7:08 am

How much coal one house requires has nothing to do with another. As I said before, make sure the unit is operating correctly and the fire has an optimal burn pattern.

coalkirk · Post by **coalkirk** » Tue. Dec. 10, 2013 7:49 am

Rob R. wrote:How much coal one house requires has nothing to do with another. As I said before, make sure the unit is operating correctly and the fire has an optimal burn pattern.

Agreed but a 165,000 BTU boiler for an 1,800 sq. ft. house? Unless his home has no windows, something doesn't add up there. I'm a firm believer in tailoring a boiler to the size of the home. Even considering the variable factors that make every home different, It's difficult to see this as a proper pairing.

Post by **Rob R.** » Tue. Dec. 10, 2013 8:25 am

I don't disagree that the boiler seems large for the task, but I think he is trying to make the best of what he has installed. A smaller boiler would have less standby losses, but that is about all. Cutting the feed back might be the best compromise.

Sting · Post by **Sting** » Tue. Dec. 10, 2013 8:32 am

Teach yourself to use heating degree days and estimate your pounds per daily/monthly/yearly use by that bench mark.

There now you know how much fuel you will need and when you will need it if you don't modify your load by adding insulation or dialing down the T-stat

Kind Regards
Sting

imcloud1 · Post by **imcloud1** » Sat. Dec. 14, 2013 3:16 pm

Like others said as long as your stack temps aren't outrageous {draft set correctly} and your ashes aren't being dumped hot {feed set correctly} you can rest assured that you are getting the heat you paid for {as long as you are using quality coal}... After them 3 things are satisfactory there are a few more ways to conserve energy.

Zoning- heat where you are using {when you are using is a nice option too, but with coal setback is iffy}
Temp control- lower your inside temps
Infiltration-seal the envelope
outdoor combustion air- {it helps, I tested the method and it works}

kstills · Post by **kstills** » Mon. Dec. 16, 2013 12:28 pm

lsayre wrote:But if the mean daily temp is currently averaging only 35 degrees right now, which equals 30 HDD's, then 45 lbs per day is only 1.5 lbs per HDD.

If the design temp of the home is -20, which is 85 HDD's, then 1.5 x 85 = 127.5 lbs. of coal for that -20 degree design day. That requires about 70,000 BTU's per hour. Toss in DHW demand on that day and 100,000 BTU's per hour sounds about right.

-20 degree day?

That's a bit extreme, isn't it?

lsayre · Post by **lsayre** » Mon. Dec. 16, 2013 12:33 pm

My area has gotten that cold (and colder, with minus 26 degrees being the record here). I would hope my system can handle minus 20 degrees if/when it happens again (particularly since my back-up resistance boiler is not functioning).

For something akin to Rob's area minus 40 would probably be a more appropriate design criteria for a heat loss calculation. It all depends upon where you live.