Steel Vs Ceramic Cat.

[BCC_Burner]

Here's another wrinkle for all of your calculations: the 26% tax credit. Hardly any non-cat stoves qualify, so if you're installing a new stove, you now need to factor that savings into how long it will take for the cat stove to be more expensive to operate than a non-cat. That tax credit extends the timeline quite a bit, and tips the scales very heavily in favor of cat/hybrid stoves.

At the end of the day, I wanted a PE Alderlea T6 more than I wanted an Ideal Steel, but the tax credit made the decision for me. With the money that will save me, I'll be able to buy 8-10 new cats before I hit the "break even" point, and there's no way I'll be living in this house, or running that stove for that long.

 

[stoveliker]

There is some selective reading going on in response to my comments.

I said either the cat is used much more than average, or it is being abused in one way or another. Responses appear to neglect my first reason.

Moreover, from October 1 to April 1 is 4350 hours or so. For a 12-15k hour lifetime one should be able to use a cat for 3-4 years.

And NO, cat lifetime is mostly related to the process flux, given equal chemistry in those flows, their hours of functioning are a proxy because the real thing is not quantifiable in a user setting - manuals only state those hours because it is impossible to say "if you burn high 40% of the time and low 70% of the time, your cat will last ..." etc. Draft (flow speed) and fuel contents (which are higher for burning on low), i.e. the reactant material fluxes (and their purity from poisons), determine the lifetime of a cat.

And, yes, this is all theory, because the determination of when to replace one can only be done properly by observation of how it operates.

 

[BCC_Burner]

It's hard to argue with the fact that 6 months is only 4,320 hours.

 

[jetsam]

Replace it when it's not getting the job done anymore. My current cat has about 15k hours on it and I am going to run it again this season.

 

[FPX Dude]

I'm running steel, still lights off as normal, lasts longer than ceramic too.

 

[Highbeam]

It's hard to argue with the fact that 6 months is only 4,320 hours.

Too bad some of us have 9 month heating seasons. Those who live where winters are short, use furnaces or other heat efficient sources, can really cut that burn season length down.

Oh and cats are not rated for 15k hours. 12k is the most common rating, used to be 10k. "Years" is a dumb metric for cat life. Hours is the best we can do.

Finally, the choice to swap the catalyst for a new one is based on the user's perception of failure. Some folks are willing to let their emissions get very high and some of use like, or are lawfully required, to keep relatively clean plumes.

I personally save at least one cord per year by using a cat stove so replacing the cat every two years so there is no break even period, I'm always money ahead. A lot of money ahead over the years. It's not just the higher efficiency of cat stoves but the long, steady burn that keeps a house warm and prevents inefficienct catch up burns and overtemping the house. There's a reason that most noncats are too inefficient to even qualify for the tax credit.

 

[stoveliker]

Too bad some of us have 9 month heating seasons.

Not in southern New Jersey...

 

[Highbeam]

Not in southern New Jersey...

Or in Panama. Yippee skippy.

I've actually recorded the useful life of several cats in my stove. They often don't even make it to 10,000 before becoming slobbery creosote dripping messes.

The good news is that for short season or part time burners, that 10,000 hours can be like 20 years.

 

[BCC_Burner]

That reflects extremely poorly on the brand of stove that elicits the kind of irrational fanaticism I stay far, far away from.

 

[bholler]

Too bad some of us have 9 month heating seasons. Those who live where winters are short, use furnaces or other heat efficient sources, can really cut that burn season length down.

Oh and cats are not rated for 15k hours. 12k is the most common rating, used to be 10k. "Years" is a dumb metric for cat life. Hours is the best we can do.

Finally, the choice to swap the catalyst for a new one is based on the user's perception of failure. Some folks are willing to let their emissions get very high and some of use like, or are lawfully required, to keep relatively clean plumes.

I personally save at least one cord per year by using a cat stove so replacing the cat every two years so there is no break even period, I'm always money ahead. A lot of money ahead over the years. It's not just the higher efficiency of cat stoves but the long, steady burn that keeps a house warm and prevents inefficienct catch up burns and overtemping the house. There's a reason that most noncats are too inefficient to even qualify for the tax credit.

Many cat stoves don't qualify either though. And really we are talking about a couple percentage points under lab conditions. That doesn't amount to much in terms of wood savings. And yes if a noncat is oversized you are going to fight with overheating the house etc. But for me going from a noncat to a cat stove of the same size I am having an issue of under heating the house now. And zero wood savings. I am far from the only one who has reported little to no wood savings when going to a cat stove.

 

[bholler]

Not in southern New Jersey...

Not central pa either. Our winters can be pretty bad but I heat at most 6 months out of the year.

 

[Highbeam]

Many cat stoves don't qualify either though. And really we are talking about a couple percentage points under lab conditions. That doesn't amount to much in terms of wood savings. And yes if a noncat is oversized you are going to fight with overheating the house etc. But for me going from a noncat to a cat stove of the same size I am having an issue of under heating the house now. And zero wood savings. I am far from the only one who has reported little to no wood savings when going to a cat stove.

I agree that the reasons for the very significant wood savings for most folks including myself is not just the higher rated efficiency of the appliance but the control of output, the long output, and steady output that happens when you properly size a stove for the application. Only a few stove companies have really dialed in their cat stoves to be able to do this efficiently and dependably.

For your example, it is obvious that your stove is undersized for the job which results in you not being able to heat your house as you report. So in an effort to heat your home have to run it way outside of the normal range. Noncats like being run hard, cat stoves are cleanest and most efficient when run long and low. It's too bad your application doesn't fit. I think you would enjoy the wood savings and comfort from those long even burns.

You guys back east have much harsher winters but short ones. Sometimes I'm jealous of that, sometimes not.

 

[bholler]

I agree that the reasons for the very significant wood savings for most folks including myself is not just the higher rated efficiency of the appliance but the control of output, the long output, and steady output that happens when you properly size a stove for the application. Only a few stove companies have really dialed in their cat stoves to be able to do this efficiently and dependably.

For your example, it is obvious that your stove is undersized for the job which results in you not being able to heat your house as you report. So in an effort to heat your home have to run it way outside of the normal range. Noncats like being run hard, cat stoves are cleanest and most efficient when run long and low. It's too bad your application doesn't fit. I think you would enjoy the wood savings and comfort from those long even burns.

You guys back east have much harsher winters but short ones. Sometimes I'm jealous of that, sometimes not.

But if I had to upsize how would that save me wood? Yes I would be loading less often but I would be loading much more wood each time. Not to mention abandoning my 6" chimney and spending atleast 3 grand to put in an 8" chimney.

And I easily heated the house running on 8 hour cycles with a tube stove sized the same as the princess on all days but the absolute worst of the winter when I would either have to load more often or let the oil pick up the slack.

The oil kicks in much more with the princess on 8 hour cycles.

 

[Highbeam]

But if I had to upsize how would that save me wood?

Sometimes properly sizing your equipment makes it more efficient. Cat stoves, like all stoves and pumps and engines and many other things, have an efficiency curve. The harder you flog the cat stove, the less efficient it is. Emissions go up too. If you are only getting 8 hour burns out of a full load in a princess then you are running that thing at nearly max output (agrees with your statement that you can't stay warm) and therefor are way off of the efficiency curve for the cat stove. Probably just as inefficient as your noncat at that point which is what you have found when comparing wood consumption. Makes total sense to me and your findings are to be expected.

Hey, I have a noncat too. They work just fine when running them at higher outputs and no cats to replace.

 

[bholler]

Sometimes properly sizing your equipment makes it more efficient. Cat stoves, like all stoves and pumps and engines and many other things, have an efficiency curve. The harder you flog the cat stove, the less efficient it is. Emissions go up too. If you are only getting 8 hour burns out of a full load in a princess then you are running that thing at nearly max output (agrees with your statement that you can't stay warm) and therefor are way off of the efficiency curve for the cat stove. Probably just as inefficient as your noncat at that point which is what you have found when comparing wood consumption. Makes total sense to me and your findings are to be expected.

Hey, I have a noncat too. They work just fine when running them at higher outputs and no cats to replace.

Again the difference in efficiency is only a couple points and I almost never ran the noncat at higher outputs. Usually closed all the way. It's just that the noncats low is pretty close to the princesses high

 

[Highbeam]

That reflects extremely poorly on the brand of stove that elicits the kind of irrational fanaticism I stay far, far away from.

I'm not sure if I completely understand your statement but real users of woodstocks and blaze kings are both seeing 10,000-12000 hour life expectancies from their cats if they are paying attention and looking at the chimneys. Those two brands are top notch in the cat world. I haven't seen reports from Kuma users if they are getting more or less than the rated life expectancy from their cats. Those Kuma guys have really gotten some excellent efficiency testing results.

If you own any modern cat stove, and with the 2020 regs there are lots of new cat stoves, it is wise to expect end of life at or around the 10k to 12k hours of burn time. It's great if you get more but be on the lookout and have a fresh cat ready. Keep an eye on your chimney.

Ignore all reference to "years of rated life" since as any child knows, you can burn a lot or a little per year.

 

[begreen]

Even in your PE, how much have you paid for wood over those 12 years of part time burning?

That gets pretty subjective. Though the PE is more efficient than the old Heritage, our house is old and not up to modern sealing standards. I have only bought wood for the past 5 yrs, and burn about 3/5s of what went through in your case, so maybe I would save 1/4 cord a year?, or maybe less because I would likely be pushing a cat stove harder than you have to. In milder weather we have the heat pump. However, with the heat pump I would probably be replacing the cat every 4-5yrs instead of every other year. Bholler's situation is more comparable and I don't recall him saving a lot more wood.

And then there is my time. I don't spend a lot of time on maintenance. The T6 burns clean, flue cleaning is every other year, door gasket replacement has been once in 12 yrs. Don't get me wrong, a cat stove is definitely good for some folks and I don't hesitate to recommend one when it's a good fit, but I don't need or want one. My preference is for a KISS stove.

 

[Highbeam]

That gets pretty subjective. Though the PE is more efficient than the old Heritage, our house is old and not up to modern sealing standards. I have only bought wood for the past 5 yrs, and burn about 3/5s of what went through in your case, so maybe I would save 1/4 cord a year?, or maybe less because I would likely be pushing a cat stove harder than you have to. In milder weather we have the heat pump. However, with the heat pump I would probably be replacing the cat every 4-5yrs instead of every other year. Bholler's situation is more comparable and I don't recall him saving a lot more wood.

And then there is my time. I don't spend a lot of time on maintenance. The T6 burns clean, flue cleaning is every other year, door gasket replacement has been once in 12 yrs. Don't get me wrong, a cat stove is definitely good for some folks and I don't hesitate to recommend one when it's a good fit, but I don't need or want one. My preference is for a KISS stove.

Bholler’s install is way different than mine. I have zero problem heating my space, 95% of the time on very low settings, where the cat stove is most efficient and clean. As seen above, that’s very much not the case with bholler’s install.

I wish cats lasted longer. It’s extremely easy to replace a cat but it is a biannual step for me. No baffle gasket to replace though!

 

[rdust]

Your mileage may vary, started burning my cat stove in 2011 and I’m on my 4th cat.(installed last season) I’d replace it every season if I needed to without blinking an eye. Savings on my body are well worth it, burned 5 cords with my Lopi Endeavor two seasons before switching to a cat stove. No more than 4 cords go through my BK stove in a season and the heat is much more even, no run away fires and repeatable load after load.

 

[Highbeam]

I almost never ran the noncat at higher outputs. Usually closed all the way. It's just that the noncats low is pretty close to the princesses high

That’s a very interesting observation.

 

[Pologuy9906]

The problem with my ceramic cat is that it gets crumbled after 2-3 years in the middle, where fire almost hits it at the beginning of the cycle due to the FPX hybrid design. This is a common problem for this stove. Never had a problem with clogging up, though. I was hoping steel cat might withstand more against direct flame.

Same thing happened to me. The cat actually fell out during a burn. It cracked then. New one cracked in the middle. That's the only reason I'm looking into a steel cat. Then you have to worry about diesel foil vs durafoil. Applied ceramics have a steel division supposedly with durafoil. They won't say. I read a BK thread and the company guy said AC has the better, durafoil.

 

[Highbeam]

Same thing happened to me. The cat actually fell out during a burn. It cracked then. New one cracked in the middle. That's the only reason I'm looking into a steel cat. Then you have to worry about diesel foil vs durafoil. Applied ceramics have a steel division supposedly with durafoil. They won't say. I read a BK thread and the company guy said AC has the better, durafoil.

AC is a very reputable company.

 

[Pologuy9906]

AC is a very reputable company.

Just ordered. Changing the door gasket while I'm at it.

 

[Highbeam]

Just ordered. Changing the door gasket while I'm at it.

Your signature says that you run a boiler. Does that boiler have a cat?

"
Flex Fuel 30kw w/ 900 gallons of storage
Pellet Hopper"

 

[Pologuy9906]

Your signature says that you run a boiler. Does that boiler have a cat?

"
Flex Fuel 30kw w/ 900 gallons of storage
Pellet Hopper"

Boiler in the basement, put in an insert. I run both. The boiler is great for my hot water and keeping the opposite side of the house warm. The insert does the areas we use most.