MKII Limits

franco b wrote:Measuring the draft directly opposite the baro might not give a correct reading. There is not enough room between the stove and baro to get a reading before the baro. If it is true that reading before or after should be the same then you have been running at .08 and not .05 because the higher reading is far enough away from the baro to read true.

If this is so it could explain your problem.

I thought of that as well, and reread the Field Controls manual for the damper to try and find out how close to the appliance the control should be installed. The instructions only indicate "as close as possible".
http://www.fieldcontrols.com/pdfs/02702600.pdf

franco b wrote:Measuring the draft directly opposite the baro might not give a correct reading. There is not enough room between the stove and baro to get a reading before the baro. If it is true that reading before or after should be the same then you have been running at .08 and not .05 because the higher reading is far enough away from the baro to read true.

If this is so it could explain your problem.

Nah ...you can't see from the pics but I have a spot on the other side before that gives a good reading.

The stove is a little on the small side for your square footage. It's bitter cold out side. Let the furnace help out a little. The air is preheated. The furnace won't run long. You'll be very comfortable. You may like it so much, you'll leave the furnace help out all the time. Oliver

oliver power wrote:The stove is a little on the small side for your square footage. It's bitter cold out side. Let the furnace help out a little. The air is preheated. The furnace won't run long. You'll be very comfortable. You may like it so much, you'll leave the furnace help out all the time. Oliver

Thanks Oliver, we did do that today and the Saudi powered unit only had to run a few minutes.

I'm making it my mission though to not fund Muslim terrorists!

franco b wrote:Measuring the draft directly opposite the baro might not give a correct reading. There is not enough room between the stove and baro to get a reading before the baro. If it is true that reading before or after should be the same then you have been running at .08 and not .05 because the higher reading is far enough away from the baro to read true.

If this is so it could explain your problem.

Yes. I agree

Wood'nCoal wrote:I think you can open up the under fire air a little more and try to get the draft in the pipe before the baro a little closer to -.04" WC. , that's about it.

I agree with this too.

oliver power wrote:The stove is a little on the small side for your square footage. It's bitter cold out side. Let the furnace help out a little. The air is preheated. The furnace won't run long. You'll be very comfortable. You may like it so much, you'll leave the furnace help out all the time. Oliver

that's what I posted but it was taken down. The Mark II is rated at 72k BTU for 1900 square feet.

FWIW, Harman dropped the Mark II and only make/sell the Mark I and Mark III now.

A good match would be a Mark III or a Magnafire SF, the latter will do 5000 square feet, and puts out 120k btu.

What are the internal firebox dimensions (firebrick to firebrick) of the Harman MKI, MKII, and MKIII?

For comparison, DS Machine's largest sized Circulator stoves BTU's appear to be related to firebox length and width as follows:

L x W x 375 = BTU's

lsayre wrote:What are the firebox dimensions of the Harman MKI, MKII, and MKIII?

For comparison, DS Machine's stove BTU's appear to be related to firebox length and width as follows:

L x W x 375 = BTU's

You hit the nail there, it all comes down to firebox size, there's only so much BTU's in any given fuel.
The Magnafire SG is on Harman's site listed at the "highest BTU coal stove on the market"- by that they must mean hand fed free standing, because there are stokers higher rated than that- don't know if that's true anymore, but it's rated at 120k btu, and will heat up to 5000 square feet. 120k BTU is more than a furnace, that's a big hand fed stove. Here's the info from their site.

Model Specifications
MAGNAFIRE SF
Front Width: 20-1/2
Height: 43
Depth: 35-1/2
Viewing Area: 8-1/2 x 4-1/2
BTU/Hour Input: 120,000
Heating Capacity*: 1,900 - 5,000 sq ft.
Magnafire SF Coal Stove
The Magnafire SF-250 Coal Stove is a true workhorse. It’s loaded with features to help you squeeze the most out of your fuel. An optional heat collector works to send hot air out into hard-to-heat places—or lets you tie into an existing system.
•120,000 BTUs — heats 1,900 to 5,000 square feet, based on climate and home efficiency
•Up to 24 hours of burn time on one load of coal
•Harman Grate System extends heating by completely burning coal to fine ash
•Highest BTU coal stove on the market

here's the Mark III
Model Specifications
MAGNAFIRE MARK III
Front Width: 25
Height: 32-1/2
Depth: 24
Glass Size: 14-15/16 x 8-1/2
BTU/Hour Input: 92,000
Heating Capacity*: 1,900 - 4,900 sq ft.

coalcracker wrote:•Highest BTU coal stove on the market

But what are its internal firebox dimensions?

SF 250 is 13" wide at the grates. My unit is divided in half. So it is 13"x 12". Actual depth about 24".