Large hot water system efficiency

So I had a large DF520 put in 2 years ago and with the very warm weather last year I used very little coal. I use Hot water cast iron radiators and cast iron baseboard.
I'm curious for any tips that others might know as far as coal consumption.

I have a 3 loop system, with a jacket and insulation around my DF520. As of now i have a boiler bypass setup but also have my pumps set up on my supply side. So if anyone out there has tips on cutting down on coal consumption let me know.

So in otherwords. What is the most efficient way to setup a DF520 with a large hot water system.

Thanks

Keep the boiler clean, and adjust the bypass & feed rate so that the stoker doesn't run for hours on end. Make sure the ash ring is correct and you are't running too much air. Check the draft, should be about -0.05" at the flue collar.

Keep your thermostat at a steady temperature, or setback only 2-3 degrees if you feel you must.

The efm warehouse had a calculated heat loss of 400K BTUH. When I set up the stoker, I went strictly by ash ring and ability to heat and that varied by the week (or day). We used 9 tons of coal over the heating season. I think the settings varied from 6 to 10 teeth.

Well then i have to do some more checking on my setup. I am burning way to much coal then. I have a large house approximately 5200 sq. ft. and i'm track to burn 20 ton this year. So i must have something wrong. The house is well insulated. Boiler has a cover on it. The major downfall is that the boiler sits in the basement which is also a 2 car garage. However, even with the jacket and insulation on the boiler the garage maintains a 66-68 degree. All the walls in the basement are blocked in and i studded and insulated all walls. So there should not be much heat loss. I'm more concerned that either my barometric damper is not set properly or that i need to pay closer attention to the ash ring. Well with warm weather on the way i will clean and check the barometric damper in hopes to set it at approximatel -.04 or-.05.

How big of a difference would it make to put pumps on return side?

Should i partially close the ball valve on the return side a little bit?

Any and all advice is welcomed.

Moving the pumps will have zero effect on the amount of coal you burn.

How much fuel/gas did you burn prior to the EFM?

Please tell us about your coal, and the feed/air aquastat settings you are using.

Also - where are you located? There might be an EFM pro nearby...

Man! Thats a lot of coal! Yes your house is real big, but there are members here who are burning that much for houses that are bigger and aren't insulated as well. Did you do the install yourself. Did the base and all the covers get sealed properly with boiler putty. How tall is your chimney? Where did you get your coal? I wouldn't think changing the pumps to the other side would make a difference. You still are moving that much heat. How much coal did you burn last year? What did you used to heat with before coal? How much?

Yeah wow, his house is a little over twice mine square footage wise but burning 5 times as much coal..
Rob has the right idea I think, get a pro there to investigate.

While we are on the topic of coal usage and how it relates to fuel feed and air ratio and and outside weather condtions I guess that if you have a more than one zone system you need to set your feed rate up to the largest btu consuming zone.That would make the smaller btu zones , when operating. less effienct yes? When the weather is cold ones neeeds to burn more fuel. When stoker man discusses the multiple feed rates based on weather it sounds that He became the automatic variable rate feed mechanism that would be hard, though not impossible to implement automatically on the 520. The variable fuel rate would be based on weather conditions. . Variable fuel ratio is the state of the art on many non solid fuel burning pieces of equipment . In essence burn just enough to warm the house relative to outside weather .When it gets colder you will burn more fuel.

While we are on the topic of coal usage and how it relates to fuel feed and air ratio and and outside weather condtions I guess that if you have a more than one zone system you need to set your feed rate up to the largest btu consuming zone.That would make the smaller btu zones , when operating. less effienct yes? When the weather is cold ones neeeds to burn more fuel. When stoker man discusses the multiple feed rates based on weather it sounds that He became the automatic variable rate feed mechanism that would be hard, though not impossible to implement automatically on the 520. The variable fuel rate would be based on weather conditions. . Variable fuel ratio is the state of the art on many non solid fuel burning pieces of equipment . In essence burn just enough to warm the house relative to outside weather .When it gets colder you will burn more fuel.

franpipeman wrote:I guess that if you have a more than one zone system you need to set your feed rate up to the largest btu consuming zone.That would make the smaller btu zones , when operating. less efficient yes? When the weather is cold ones needs to burn more fuel.

If you have a small zone call for heat, the boiler will simply run until it reaches the high limit and then shut off...assuming you have the controls setup that way. If nothing else calls for heat for several hours, the heat stored in the boiler will be lost to the surrounding area and to the chimney. In my case, the boiler keeps the basement comfortable and the heat going up the chimney maintains a good draft...so I don't worry about it.

When you have multiple zones of varying size, the a control that adjusts the boiler temperature based on load becomes beneficial. Constant/frequent circulation is also nice with a high-mass system.

Okay so let me give you some updates.

I'm located in Clearfield Pa. just off of interstate 80 (5miles).

I have a really high chimney. I'm guessing 35 ft atleast.

Coal usage in the past
-last year i used very little because of the temp and the fact that i had a lot of oil i needed to use up.
-2 years ago. i used roughly 13 tons and some of the oil that was left over when i bought the house.

So to be honest i do not have a good estimate of how much coal i should be using. all i know is that based upon what everyone is saying about coal usage... i'm using way to much.

Rob R. wrote:Please tell us about your coal, and the feed/air aquastat settings you are using.

Have you cleaned the boiler recently?

I forgot to mention that i got the coal from a very good company back this way called Roaring Run. I have an in there, but i'm 99% sure that the coal came from Reading Pa.

I cleaned prior to start up. Vacuumed everything and scrapped down all sides. There was no fly ash on inside.

Currently i have my aquastats at 150-190 with a 10 degree differential on both high and low limits.

I adjusted my coal to 4 clicks and 4 air last night. and seemed a little better. i also slightly closed my valves on the return in hopes that the boiler would not get "shocked" by the cold return.

CoalBurner5 wrote:I adjusted my coal to 4 clicks and 4 air last night. and seemed a little better.

What were you running before? 4 teeth seems pretty "light" for the load you have described.