Is my exhaust temp too low?

Howdy there, so recently fired up a RMH built out in North Western Montana.
Good news is it works seemingly well. Been running it since Friday evening - it's now Sunday evening. Now it' isn't terribly cold and next winter will be it's real test but the furnace hasn't come on since we fired it up.

Big thanks to Thomas Rubino for the guidance to me as a young guy and for the batch box door.

So like I said it seems to work, we're reading temperatures of the high 800s at the top of the barrel and our heat exchange bench is warm and we've experienced yet no issues with smoke going anywhere except where it's suppose to.

My question revolves around my single concern at this point. We have a thermometer about 4 feet up the chimney pipe sticking out the flue to collect the temperature for learning data. We're stable at about 110 degrees F - this is the concern for me; for now it works well but from my current understanding we'll need a hotter exhaust exit temp if it's to draft sufficiently during colder months. Something more like 180-200 degrees, according to my current knowledge?

Looking for ideas how to make it, 'less efficient' or to not capture so much heat that we can achieve hotter exhaust temperatures.  My current thoughts are 1; insulate cleanout caps (we fabricated a decorative metal cap - this is a place where we could reduce heat escape) 2; shorten chimney? our chimney top sticks out nearly 8 feet, I'm thinking if we reduce it down to the minimum of 36inches it'll give us better draw on colder days.
Any and all other suggestions are welcome. Hoping to not have to get in there and redesign some of our duct work to shorten the system.

Attached a couple pictures and here's a video link.



         

Hey Isaac;  Looking Great!
Thanks for sharing!

Is the bypass open or closed when you are running 110F?
The problem burning at that temperature, is not so much draft as condensation.
Above 140F that problem goes away.
180-200F is an ideal exit temp to shoot for.

It takes longer than you think it should, to completely dry out and heat up your system, so you may see more improvement.
Trying to burn in these temps is tough, although the bypass helps immensely.
Your draw will improve the colder it is outside.
Keep burning while you can. Soon it will be to warm.

Bypass had been closed for awhile when taken those readings and pictures.

Thank you! It's been fun thus far! Happy to see it running and providing heat for the people living here.

Also can I ask a couple clarifying questions - those ideal numbers of above 140, or better 180-200 for condensation: that applies to applies to the ideal temp at the bottom or out the top of the chimney?


Also I have a hard time understanding why it'd draw better when cold, for some reason I thought it'd be worse when cold.

Thanks

OK, stack temperature is taken when it goes vertical and leaves the mass.  .
Your chimney is insulated, so higher up near the top might be cooler but not very much.

The colder it is outside the larger the temperature difference. Called "Delta T" your warm air wants to escape that chimney and it races for the exit.
When it is warm outside it is much harder to get the flow going, there just isn't a good incentive to draft well.

As far as your chimney height.
I'm a fan of make them as short as you can.
If you can shorten yours down without having any wind issues then I would do so.

Can you bring the stack temperature up to 140F or more running with the bypass open?

The taller a warm chimney is, the better the draft will be (within reason). But, if a tall chimney is cold at the top, that will hurt draft, and you would benefit from shortening it to what is needed to avoid downdrafts.

A given diameter or cross section of chimney at a given temperature difference inside to outside will have a certain draft speed that it can maintain for an unlimited height. This ideally matches or exceeds by a bit the amount of air you want going through the system. If you want more air through the system, a shorter chimney will allow that easier. If the top of the chimney cools significantly, you will lose draft capacity.

https://en.wikipedia.org/wiki/Stack_effect