BK or NC-30?

[begreen]

Further blog posting:
Kevin Purcell said...

Isaac Molitch asks "At what elevation should we be above the fog zone this week?"

Above the inversion ... you can see the current height of the inversion on the virtual stemp plot (or the Stuve plots).

See the Upper-Air Observations: Soundings and Profiler Data

http://www.atmos.washington.edu/~ovens/loops/

Today the inversion is down to around 800m (2500 feet) so you need to get onto a decent sized foothill to guarantee it. The passes should be above it.

Altitude is relative. There are notable temperature inversions that occur around Mexico City starting at 7000ft..

 

[Highbeam]

Yes, but BG, an inversion line while interesting is not the same thing as the pollution line. You seem to be trying to make them one in the same.

 

[Ashful]

Add this to the already-long list of reasons I'm glad I don't live on the left coast.

 

[iron]

not to interrupt the thread drift, but did you guys have thoughts on my last two sets of questions?

 

[begreen]

Thought they were answered, no? The BK will smoke less on a hot reload. Most of the smoke generated is getting the cat up to temp. Both the BK Princess and 30 series + Englander stoves have 6 in. flues.

 

[begreen]

Elevation of the top of the cloud deck is not the same as the elevation of the pollution that meets the threshold. Note that most of the monitoring stations used are down near sea level. It's a stupid system. Transportation pollution is a large source of the particulate being measured and the freeways and ports spew this out at low elevations where it stays.

Not cloud deck, though that is an indicator. My understanding is that it's temperature layering and cooler air descending to lower altitudes that is the issue. The warmer air is typically above the cloud deck, the clouds being where the cooler air starts condensing moisture. Remind me to take a picture pointing your way during the next serious winter temp inversion. I've emailed Cliff Mass at UW atmospheric lab with the question for a more accurate response.

 

[iron]

question about the alcove heat retaining opportunities:

i know with the upstairs fireplace (northstar ZC), the masonry captures a ton of heat and will stay warm for many hours after the coals have died out. obviously, this fireplace is built into and more or less touching the masonry, so that helps a ton.

but, in an alcove surround, if you place masonry all around the stove, especially above it, would you be able to retain a lot of heat? just wondering if the nc-30 could work in that regard.

the idea of having a stove box with a black window the whole time isn't very appealing to me. i like the idea of 24hr burns and low, steady heat. but it seems like a sacrifice on the aesthetics. i know that i'm still new to the wood burning world, so maybe that effect will wear off over time, but what's the point of a glass window if it's dirty the whole time?

^ this question

thanks

 

[begreen]

Add this to the already-long list of reasons I'm glad I don't live on the left coast.

Temperature inversions happen on the east coast too in many PA, NY and WV valleys where there is a lot of winter wood burning. I've lived on both coasts and won't move back east. No love here for bugs, hot humid summers, shrink wrapped veggies, snow shoveling, rusted cars and road salt. Nice place to visit in early October though.

 

[begreen]

^ this question
question about the alcove heat retaining opportunities:

i know with the upstairs fireplace (northstar ZC), the masonry captures a ton of heat and will stay warm for many hours after the coals have died out. obviously, this fireplace is built into and more or less touching the masonry, so that helps a ton.

but, in an alcove surround, if you place masonry all around the stove, especially above it, would you be able to retain a lot of heat? just wondering if the nc-30 could work in that regard.

The 30NC is a heavy stove so it has a fair amount of mass to start with. The alcove could be engineered somewhat to store more heat. It would take having that mass isolated and insulated from the cold foundation wall. I suspect it would be more efficient to buy a stove that has the mass very close to the stove body by design. There are several now on the market that are steel stoves with a cast iron jacket. The BK Ashford 30.1, Jotul F55 or the PE Alderlea T6 are examples.

 

[prezes13]

If I was you I would get a BK stove. I live in a raised ranch in ct. I have an insert on my living floor roughly 1200sf. My daughter is using our rec. room downstairs more and more so I am thinking about installing ashoford 39 there so I could het that and upstairs.

 

[Ashful]

FWIW, my experience with my BK Ashford 30 is quite different than Highbeam's. Different stove, different age, different wood (I burn almost exclusively oak, these days, with some ash and hickory). Mine only smokes less than 10 minutes on a reload, and I'd not call it "freight train" by any means. Just a light gray smoke, which is mostly steam, not particulate. At the 8 minute mark, after reload, I close bypass damper and she goes clean within 2 minutes. By "clean", I mean nothing but clear air with heat ripples.

 

[tarzan]

FWIW, my experience with my BK Ashford 30 is quite different than Highbeam's. Different stove, different age, different wood (I burn almost exclusively oak, these days, with some ash and hickory). Mine only smokes less than 10 minutes on a reload, and I'd not call it "freight train" by any means. Just a light gray smoke, which is mostly steam, not particulate. At the 8 minute mark, after reload, I close bypass damper and she goes clean within 2 minutes. By "clean", I mean nothing but clear air with heat ripples.

Ashful, I live just south of you and burn much the same woods as you but from day one with the Princess my experience more resembles Highbeems. Upon reload I see huge amounts of smoke that last for at least 30 minutes. After that, in warmer weather there is still some puffs of smoke. I inquired of this on the 14-15 BK thread and was told "normal."

 

[begreen]

Most stoves smoke a bit on reload until the load has reached temperature and ignites. But normally this is like 5-10 minutes with dry wood. Once the load is burning there should be no smoke.

 

[Ashful]

30 minutes of smoke?!? When are you engaging the cat? If I left my bypass open 30 minutes on a reload, it would be a molten puddle in the bottom of the stove.

Depending on amount of coals at reload, I'm always closing that bypass in 8 - 12 minutes. Cat hits active temperature within a minute or two after that, and I'm clean. Only way I could imagine getting smoke for 30 minutes is on a cold start with wet wood.

 

[Highbeam]

30 minutes of smoke?!? When are you engaging the cat? If I left my bypass open 30 minutes on a reload, it would be a molten puddle in the bottom of the stove.

Depending on amount of coals at reload, I'm always closing that bypass in 8 - 12 minutes. Cat hits active temperature within a minute or two after that, and I'm clean. Only way I could imagine getting smoke for 30 minutes is on a cold start with wet wood.

I don't think we are "quite different" on hot reloads. 10-20 minutes to be clean again is not out of line. The long, freight train smoke outs are during cold starts when these cat stoves are built like old smoke dragons. Just primary air and a direct shot from fire to flue without a baffle.

I absolutely will have smoke during warm up when the cat is engaged and active/glowing bright orange. Engaged cat does not mean smoke free. I engage the cat as soon as the needle says active. The wood is not wet at all, three years aged in fact. In the non-cat, this wood is smoke free in very short time. After some time, the smoke reduces to clear for a very long time.

Your ashford is a different stove and your chimneys are very tall. Perhaps one of those factors is helping you get the extra long burn times and early clearing exhaust.

 

[tarzan]

30 minutes of smoke?!? When are you engaging the cat? If I left my bypass open 30 minutes on a reload, it would be a molten puddle in the bottom of the stove.

Depending on amount of coals at reload, I'm always closing that bypass in 8 - 12 minutes. Cat hits active temperature within a minute or two after that, and I'm clean. Only way I could imagine getting smoke for 30 minutes is on a cold start with wet wood.

I engage the cat as soon as it hits the active range. My procedure is much the same as yours but I still get smoke until the cat probe gets to 12 or 1 o'clock. Even then it slowly dissipates, not instantly burning clean by a long shot.

I have been a little suspect of my cat from day one. This is the reason I questioned it on the 14-15 BK thread. I can describe it as lazy for lack of a better word. I also noticed that toward the end of last season it would smoke even more than usual and even clogged up twice. I could burn a hot fire and rejuvenate it but that was just a temporary fix.

I don't have enough chimney but I'm not convinced that's part of the problem. I never get smoke when opening the door and have no trouble getting a fire going on a 45*F day. Both are signs of good draft.

I will likely go into this burning season with a new cat so we'll see if anything changes.

 

[Ashful]

My cat is new, so a little hyper-active, which may be why I'm seeing much cleaner results faster (and longer) into the burn. I would guess that based on tarzan's comments, your cat might be depleted. In my case, active cat does usually mean smoke free, or darn close to it. Maybe that will fade with time, I have just over a year on each of the Ashford 30's.

 

[Highbeam]

My cat is new, so a little hyper-active, which may be why I'm seeing much cleaner results faster (and longer) into the burn. I would guess that based on tarzan's comments, your cat might be depleted. In my case, active cat does usually mean smoke free, or darn close to it. Maybe that will fade with time, I have just over a year on each of the Ashford 30's.

Yes, fresh cats really do make a difference. It is worth it to many of us to not wait until total cat failure but to replace them when they are still very effective.

 

[tarzan]

My cat has always allowed some smoke to get by for a while after a reload and I could always catch a puff of smoke occasionally if I was outside on a cool Fall day. When it was new though, I could turn the t-stat completely down, cat would turn bright orange, probe would go to or past 3 o'clock and run that way for hours. Man I miss that hyper active cat!

Highbeem and Ashful, I know both of you have purchased cats, any advice?

 

[begreen]

My cat is new, so a little hyper-active, which may be why I'm seeing much cleaner results faster (and longer) into the burn. I would guess that based on tarzan's comments, your cat might be depleted. In my case, active cat does usually mean smoke free, or darn close to it. Maybe that will fade with time, I have just over a year on each of the Ashford 30's.

IIRC you have both a tall and a short chimney setup. Do you see differences in behavior or smoke with one setup vs the other?

 

[Rdub564]

I installed a quiet bathroom fan in my LR above my stove and piped the discharge into my central heating system. The fan is super quiet and slowly circulates the warm air to the bedrooms. The fan can be stopped or started depending on whether we want more or less heat in the bed rooms. The fan can also be used to just remove hot air from the LR if we over fire a bit. The fan can be hooked up to a dimmer light switch and the flow can be controlled but I found that on/off works for me. I have just purchased a BK princess and expect it to work even better than my old stoves with this fan system.

 

[Highbeam]

Man I miss that hyper active cat!

Highbeem and Ashful, I know both of you have purchased cats, any advice?

I've run both ceramic and steel. That's the only choice you have to make that and frequency of replacement which I'm thinking will be around 3 years for me. No difference in operation or clogging but in theory, the steel is less likely to be damaged from thermal shock via leaky door gasket which is what kills 95% of cats according to BK. The other thing is that the steel has more surface area so it should have more catalyst and more of that catalyst exposed to the smoke.

IIRC Woodstock no longer uses ceramic and BK quit using them on the newer, cleaner models. But still uses ceramic on the older models but some have steel. Seems to be a supply issue. BKVP prefers ceramic, something about it being slower to cool after it runs out of fuel, slower to heat up too.

The cats are very easy to swap out but you need a new gasket every time. New cats come with the gasket.

 

[iron]

dang, a new cat every 3 years? i guess you burn more than we ever would, but still, that's a semi-pricey maintenance cost.

 

[begreen]

IIRC, according to BKVP lifespan of a well-treated cat is 6-10yrs. At 6 yrs I would hope to still have 80% activity.

 

[iron]

so at 80% activity, what is the emission rate? if the stove is smoking all the time on reloads, doesn't that kind of defeat the purpose of a clean burning EPA stove?