Kaa-4 burn rate

nepacoal · Post by **nepacoal** » Mon. Dec. 24, 2018 8:18 am

I finally installed an hour meter and measured my burn rate. Measured over a few days and 280 pounds of buck, I am getting a Max burn rate of 6.5 lbs/hr (6.5053 actually). It is set about 7 turns out and has right at 1.5 to 2 inches of ash. I might be able to squeeze a tiny bit more out of it when it's below zero, but with the over fire draft right at -.02 when OAT is 20, I doubt it would be worth it.

It is installed in the basement of a two story 1940's cape cod with an internal chimney 25 to 28 ft high. It has 450 square feet of radiation (approx 77,000 btu).

lzaharis · Post by **lzaharis** » Mon. Dec. 24, 2018 9:17 am

I am using a buckwheat rice mix and my stoker is set at 12-14 threads out on average.

Qtown1835 · Post by **Qtown1835** » Mon. Dec. 24, 2018 12:35 pm

lzaharis wrote: ↑
Mon. Dec. 24, 2018 9:17 am
I am using a buckwheat rice mix and my stoker is set at 12-14 threads out on average.

I'm in the same range 12-15turns out. I think I'm at 15 right now.

nepacoal · Post by **nepacoal** » Mon. Dec. 24, 2018 1:14 pm

You have the old style Q... With the sloped, inclined grates. Mine is the new style with flat grates. It is a completely different unit. I would expect the older style to be different. That is why I put kaa-4 in the subject.

Qtown1835 · Post by **Qtown1835** » Mon. Dec. 24, 2018 2:02 pm

Oops. Good point. What hour meter did you install?
**Edit**. Found your other thread

nepacoal · Post by **nepacoal** » Mon. Dec. 24, 2018 2:04 pm

Qtown1835 wrote: ↑
Mon. Dec. 24, 2018 2:02 pm
Oops. Good point. What hour meter did you install?

Here you go... Surface Mount Hour Meter

nepacoal · Post by **nepacoal** » Sat. Feb. 29, 2020 6:14 am

It's been a slow weather year here in coal country so I've been playing with my feed and air to see how much coal the KAA-4 can actually push under typical weather... I had never actually double checked my feed to see how many turns out (lost count several years ago when I adjusted for all buck). Here are the numbers for this year's Lehigh buck with my newer 1.75 RPM stoker:

6 turns out - 6.50 lbs/hr
5.5 turns out - 6.83 lbs/hr
5 turns out - 7.26 lbs/hr

I can run at 7.26 lbs/hr up to 40 or 45 OATs. Above that and I can't really get an over fire draft of -.02. I'll definitely need to reset both air and feed back down to 6.5 for the summer...

So, during normal winter conditions, my system has just under 91k input BTUs.

lsayre · Post by **lsayre** » Sat. Feb. 29, 2020 11:53 am

nepacoal wrote: ↑
Sat. Feb. 29, 2020 6:14 am
I can run at 7.26 lbs/hr up to 40 or 45 OATs. Above that and I can't really get an over fire draft of -.02. I'll definitely need to reset both air and feed back down to 6.5 for the summer...

What's 40 or 45 OATs mean if I might ask?

Nit picking for sure, but I generally presume 12,250 BTU's per "as delivered" pound of typical anthracite. That puts you at an input of 89,000 BTUH. No real difference.

Post by **Rob R.** » Sat. Feb. 29, 2020 12:03 pm

Outside Air Temperature. At higher temperatures he likely does not have adequate draft to support the higher feed & air settings.

If 6.5 lbs/hr heats the house fine I would just leave it there year-round.

nepacoal · Post by **nepacoal** » Sat. Feb. 29, 2020 12:32 pm

lsayre wrote: ↑
Sat. Feb. 29, 2020 11:53 am
What's 40 or 45 OATs mean if I might ask?

Nit picking for sure, but I generally presume 12,250 BTU's per "as delivered" pound of typical anthracite. That puts you at an input of 89,000 BTUH. No real difference.

Outside air temp - OAT

lzaharis · Post by **lzaharis** » Sat. Feb. 29, 2020 12:36 pm

I switched back to Blashack Rice coal last heating season and I am running our kaa-4-1 at 7 turns out and it is burning their rice coal very nicely.
My hold fire timer has a total of 14 minutes of run time in four segments every thirty minutes to keep the fire going and it has been running very well and very slowly despite the leaky house.

nepacoal · Post by **nepacoal** » Sat. Feb. 29, 2020 12:37 pm

6.5 lbs/hr does heat the house fine... Not sure it would at -10 with high winds, but 99% of the time it would be fine. It also supplies DHW, so recovery time is also a factor. At 7.26, it recovers a little faster and obviously has about 12% more BTUs

lzaharis · Post by **lzaharis** » Sat. Feb. 29, 2020 12:45 pm

My domestic coil failed(thanks much keystoker) and I am no longer using it to make supplemental hot water.

I will be installing an external domestic hot water coil when I can afford a shell and tube Domestic Hot Water coil.

lsayre · Post by **lsayre** » Sat. Feb. 29, 2020 1:04 pm

lzaharis wrote: ↑
Sat. Feb. 29, 2020 12:45 pm
My domestic coil failed(thanks much keystoker) and I am no longer using it to make supplemental hot water.

I will be installing an external domestic hot water coil when I can afford a shell and tube Domestic Hot Water coil.

You might consider a water to water plate and frame heat exchanger for DHW. They are generally quite inexpensive.

https://www.brazetek.com/application-hot-water-he ... -exchanger

lzaharis · Post by **lzaharis** » Sat. Feb. 29, 2020 1:16 pm

Hello Larry,

I will price them out and then make a decision sometime when the heating season is done. The whole business still rankles me to be polite about it all. The previous shell and tube system on my hand fed wood and coal boiler I had gave me no problems for 33 years.