MKII Limits

Post by **franco b** » Sat. Dec. 14, 2013 8:51 pm

Gekko wrote:So increase the exhaust draft?

I've had the side temps @ 625 with exhaust flange temps @ 400.

Harman says it's over firing @ 500 measured at the exhaust flange or before the baro.

That's my point, is this thing flat out?

Is that with the blower on? Also it would be expected to have higher stack temp. when burning off volatiles after re loading but not after that with a settled fire.

scalabro · Post by **scalabro** » Sat. Dec. 14, 2013 8:54 pm

franco b wrote:
Gekko wrote:So increase the exhaust draft?

I've had the side temps @ 625 with exhaust flange temps @ 400.

Harman says it's over firing @ 500 measured at the exhaust flange or before the baro.

That's my point, is this thing flat out?
Is that with the blower on? Also it would be expected to have higher stack temp. when burning off volatiles after re loading but not after that with a settled fire.

Yes that's with the fan on.

The surface temps will go higher with it off.

I think I'm answering my own question ... I need, well, I want more stove, LOL!

michaelanthony · Post by **michaelanthony** » Sat. Dec. 14, 2013 8:58 pm

Hi Gekko, my box stove similar to your Harman never had the high temp as you at the breech, it is normally in the 220, 260 range and even then I thought it was high so I installed a mpd about a foot away from the back of the stove and a foot and a half before the baro. This set up slowed the gases and dropped the temp of the pipe before the baro to approx. 160 and 100 to 120 after therefore keeping more heat in the basement. I am getting slightly longer burn time on a bag of coal of a few hours and that adds up to less coal per 24 hours. Have you checked your gaskets this year?

scalabro · Post by **scalabro** » Sat. Dec. 14, 2013 9:05 pm

Not with a dollar bill.

Just did a smoke test with my cigar, all good no air infiltration.

Post by **franco b** » Sat. Dec. 14, 2013 9:05 pm

Try lowering the draft to .03 before the baro. your draft at .08 after the baro is very high. That high draft will pull more air than is needed through the secondary air slots and raise stack temp.

scalabro · Post by **scalabro** » Sat. Dec. 14, 2013 9:09 pm

franco b wrote:Try lowering the draft to .03 before the baro. your draft at .08 after the baro is very high. That high draft will pull more air than is needed through the secondary air slots and raise stack temp.

I'll do that tomorrow, don't want to experiment with draft tonight before bed!

Perhaps an MPD before the baro?

Thanks for all the suggestions guy's.

This is a great place to hang out!

rberq · Post by **rberq** » Sat. Dec. 14, 2013 9:14 pm

Gekko wrote:I think I'm answering my own question ... I need, well, I want more stove, LOL!

Yes, it sounds like the Mark II is maxed out or close to it, and you need (as well as want

) more stove. You could get a little more heat out of it, but who wants to be straining yourself and the stove to run at max all the time?

Post by **Lightning** » Sat. Dec. 14, 2013 9:15 pm

franco b wrote:Try lowering the draft to .03 before the baro. your draft at .08 after the baro is very high. That high draft will pull more air than is needed through the secondary air slots and raise stack temp.

I don't understand how you are seeing these pressures. Could someone please explain? What is meant by before and after baro?

Post by **franco b** » Sat. Dec. 14, 2013 9:22 pm

Lightning wrote:
franco b wrote:Try lowering the draft to .03 before the baro. your draft at .08 after the baro is very high. That high draft will pull more air than is needed through the secondary air slots and raise stack temp.
I don't understand how you are seeing these pressures. Could someone please explain? What is meant by before and after baro?

Before baro is between the stove and baro and after baro is between the baro and chimney, if I understand it correctly.

scalabro · Post by **scalabro** » Sat. Dec. 14, 2013 9:24 pm

franco b wrote:Try lowering the draft to .03 before the baro. your draft at .08 after the baro is very high. That high draft will pull more air than is needed through the secondary air slots and raise stack temp.

Sorry for any confusion, I made a typo in my Posting my drafts are .05 before the baro and .08 after.

Harman recommends a minimum of .06 .

On a dry day below 0 deg my chimney will easily draw over 1.4

CoalHeat · Post by **CoalHeat** » Sat. Dec. 14, 2013 9:30 pm

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.

Post by **franco b** » Sat. Dec. 14, 2013 9:34 pm

Gekko wrote:
franco b wrote:Try lowering the draft to .03 before the baro. your draft at .08 after the baro is very high. That high draft will pull more air than is needed through the secondary air slots and raise stack temp.
Sorry for any confusion, I made a typo in my Posting my drafts are .05 before the baro and .08 after.

Harman recommends a minimum of .06 .

On a dry day below 0 deg my chimney will easily draw over 1.4

You might read the posts by King coal who had a similar problem with his DS Machine stove and wound up using both a baro and manual damper.
I read the baro numbers just as you intended. I did not notice you left out the zeros.

Post by **Lightning** » Sat. Dec. 14, 2013 9:44 pm

franco b wrote:Before baro is between the stove and baro and after baro is between the baro and chimney, if I understand it correctly.

I've taken measurements before and after baro and they were always the same.

And why would a measurement after the baro be meaningful if it was different??

Are you sure he doesn't mean a MPD?? This would show different pressure on each side..

CoalHeat · Post by **CoalHeat** » Sat. Dec. 14, 2013 9:49 pm

They should be, unless that high reading was due to turbulence around where the test point is (after the baro).

Post by **Lightning** » Sat. Dec. 14, 2013 9:51 pm

He must be mistaken a MPD for a baro...