fireboxes 2.5cf vs 3.0cf: worth the switch?

[60acres]

What do people think of switching from a stove/insert with a 2.4cf firebox to one with a 3.0 cf firebox? Obviously, a person would get some more heat out of the larger unit, but would it be worth the thousands it would cost to make the switch? Would I notice a significant difference in my house? Has anyone made a switch of this kind?

I've had a Hearthstone Clydesdale insert for 5 yrs. 2.4cf firebox. It works great, burns clean, throws off lots of heat. But it's in a huge room, about 25 x 40 ft with a cathedral ceiling about 20ft up at its highest point. I've got ceiling fans. My house is decently but not superbly insulated without enormous air leaks. I harvest my own wood, mostly Maple, Ash, and Red Oak. On many winter days I'll keep the stove burning all day, but when I'm lazy or too busy at work, it'll just be from about 4pm on. The Clydesdale does a lot to heat this space, and with temps in the 20s I reach the low-to-mid 60s without much of a problem, but not usually more than that. In the teens and single digits outside, I'm in the low 60s inside without another heat source. In the 30s and above, the Clydesdale gives me all the heat I could need.

I have to have an insert, not a freestanding stove, so the biggest I can go is a firebox around 3cf (Olympic, Summit, etc). Would I notice a lot more heat from that? I figure it means I could add about one more split each time I reload, and I'm not sure that's worth the cost of going bigger. I spoke with two different shops, and one said I would notice, the other said they'd love to sell me a new insert, but thought it would absolutely not be worth it, especially if I like the look of the Clydesdale, which I do.

Thoughts?

 

[Jags]

You will make a better decision if you take actual measurements of the box (internal). It will be easier to determine the true wood load. I think some of the cuft claims on different stoves are a bit wonky. You may find out the the bigger box is the same as the old but 1.5" longer. Is that worth it? Probably not.

 

[Hardrockmaple]

You have a lot of stove (insert) already, have you considered upgrading the insulation from decent to very tight? I've found that my little stove feels much more powerful (larger ?) since spending the time and money on improving my "envelope" by adding insulation and filling as many wee cracks that I could find.

 

[branchburner]

Prolly not worth it. But if you look, you can find an insert bigger than 3 cu ft.
(broken link removed to http://www.woodstoves.net/country_flame/bbf.htm)

 

[60acres]

Thanks All,

All three comments make lots of sense.

1) Adding an inch in length to the box isn't going to make any difference at all, unless I'm pretty precise every time I cut a piece of wood for the insert! For all my thinking, I hadn't considered that it might matter where the volume was added to the box, or even if the reported measurements would be right.

2) As for insulation, I'd love to add some, but it's a huge proposition doing that with a cathedral ceiling. Maybe I should save the thousands on the insert and put it toward my savings for a new roof. Better environmentally too. That's the weak spot in my insulation. It's R-19 should be more like r-50 up there, but I have to tear the place apart to add or nail foam over the existing sheathing.

3) Yeah, I've seen bigger inserts than 3.0, but I really favor the non-cats over the catalytics and the biggest ones all seem to be cats. Can't have everything I guess.

So no one is rushing to say get the 3.0, except for one guy who might be selling it to me. I appreciate the shared opinion.

 

[Shari]

All good responses - let's look at this from a slightly different angle:

Tell us about your install -

1. Interior or exterior chimney?

2. Is your chimney lined?

3. If lined, is your liner insulated?

4. Do you have block-off plates at the top and the bottom of your chimney?

If you are missing 2,3 or 4, by upgrading those items you just might get more heat out of what you already have.

And: Welcome to hearth.com!

 

[BrowningBAR]

Thanks All,

All three comments make lots of sense.

1) Adding an inch in length to the box isn't going to make any difference at all, unless I'm pretty precise every time I cut a piece of wood for the insert! For all my thinking, I hadn't considered that it might matter where the volume was added to the box, or even if the reported measurements would be right.

2) As for insulation, I'd love to add some, but it's a huge proposition doing that with a cathedral ceiling. Maybe I should save the thousands on the insert and put it toward my savings for a new roof. Better environmentally too. That's the weak spot in my insulation. It's R-19 should be more like r-50 up there, but I have to tear the place apart to add or nail foam over the existing sheathing.

3) Yeah, I've seen bigger inserts than 3.0, but I really favor the non-cats over the catalytics and the biggest ones all seem to be cats. Can't have everything I guess.

So no one is rushing to say get the 3.0, except for one guy who might be selling it to me. I appreciate the shared opinion.

It being an insert makes it hard to say. Would a Lopi Declaration (2.9 cu ft) throw out noticeably more heat then the Clydsdale (2.4 cu ft)? Maybe. Is it worth the expense? Probably not. If you are going to make the jump, it would have to be a much larger stove in order for you to appreciate the difference. I think the cat/non-cat issue is a non-issue. If you are looking for a larger insert that will produce a lot more heat, you should at least check out the big cat inserts.

The Country Flame BBF insert has a 3.9 cu ft box. I'd bet you would notice a difference with that stove.

 

[60acres]

Thanks for the welcome. I've lurked for years and have seen posts from some of the people now responding, so that's great.

Shari, yes to all 4 questions:

1) It's on an outside wall.
2) It's lined.
3) Insulated all the way up.
4) Block off at the top and bottom, though the one at the bottom could probably be slightly improved.

I've even lined the old open fireplace with rock wool in the hope of avoiding too much heat transfer to the outside stone.

BrowningBar,
That's interesting that you think the cat/non-cat is a non-issue. I've never worked with a cat stove and so I have my apprehensions based only on stories. I bet I would notice the difference with one of those 4cft boxes, and it would fit. I've got an enormous old stone fireplace.

Thanks. I'm going to see if I can find someone locally who runs a cat stove to check it out.

 

[branchburner]

An issue may be your liner, which I assume is 6", while most of the big cats suggest 8".

 

[Fsappo]

Having sold a lot of Clydesdales and also a lot of Regency I3100s and being in many homes with them burning as a follow up, the I3100 out heats the Clydesdale pretty handily. The Clydesdale is a beautiful stove, with a huge glass and a long even heat life. I love the stove, but I always sell it as a medium sized model, designed to warm up a couple of average sized rooms with a luxurious comfort and style.

For a raw heating machine, I sell the I3100. The .4cf firebox difference doesn’t sound like a lot on paper, but the end result in the room is extremely noticeable

 

[EatenByLimestone]

Big rooms like that often have large amounts of windows. Since the best windows are somewhere around R3 you could be loosing a good amount of heat here. Is there any way to draw insulated shades over some of them? Maybe a bit of that shrink wrap stuff over the upper ones?

Matt

 

[ddddddden]

+1 AOTA. All that space, yet no room for a freestanding stove? Option 3: bust up the fireplace and brick it up as a hearth for a freestander, like GlennMike did with his NC 30, and Todd did with his Keystone. Both beautiful installs! Good info from Franks indicating that the Clydesdale may be somewhat anemic for its size, but if I were going to bother to swap, I'd go B!G. +1 on the Country Flame BBF, or a Buck 91. If you absolutely refuse to catalyze, Buck has just released the non-cat 94, which very interestingly shows a lower output spec than its cat brother. The 94 is the only non-cat 4+ cu fter I've heard of, maybe with good reason. According to Oyen, "Pacific Energy is the only co that we know of to solve the problem of controllability in a 3+ cu ft non-cat firebox. . .EBT." (broken link removed to http://chimneysweeponline.com/hoebt.htm) Efficiency debate aside, nobody denies that a cat stove gives you greater control over the burn, and the importance of this issue is apparently magnified in the larger stoves.

 

[ddddddden]

Option 4: Remove the surround from the Clydesdale and see if that lets more heat from the sides of the stove into the room. Some insert owners have reported positive results with this. Option 5: Freestanding stove in the fireplace, without remodeling, if the fp is big.

 

[60acres]

Thanks for more good ideas.

1) In the best of all worlds, I'd be able to try something like the Regency i3100 and see if it was a notable improvement. Obviously, no shop is going to go for that, its a bet of several thousand if I go for it. It's good to know that someone's experience says it might. The problem with thinking about different stoves outheating one another in different houses is that its so hard to control for all the variables. Is the Regency heating much better because its being operated differently? Because one house is sealed/insulated better than another? Floor Plan? Placement of fire. In other words, are all the differences observed by Franks completely traceable to the difference between the stoves?

2) I'm sitting near sliding glass doors, about 9ft long by 7ft high, so, yeah, lots of windows. Double paned, but still. Increasingly I think I ought to get some thermal blinds.

3) The Buck 94 is a monster. Really. I hadn't seen that one. It would fit easily.

4) Those installs into/in front of fireplaces look great. I think I could just about jam a Hearthstone Equinox into my fireplace, given the size, but I think a lot of heat would get trapped. I don't want to do lots of masonry work.

There's always the possibility of using the oil boiler to make up a few degrees, too, but that's no fun at all.

I appreciate all the thoughts.

 

[EatenByLimestone]

Just for giggles, hang a blanket over a window and see how big the temp difference is on each side of the blanket.

Matt

 

[branchburner]

I think I ought to get some thermal blinds.

Can't hurt.

 

[SolarAndWood]

I went from claimed 2.3 to claimed 4.3 and now sleep as long as I want. It was worth it to me.

 

[BrowningBAR]

I went from claimed 2.3 to claimed 4.3 and now sleep as long as I want. It was worth it to me.

I would rather have an issue with too much heat than always wanting a little more.

 

[Valhalla]

What do people think of switching from a stove/insert with a 2.4cf firebox to one with a 3.0 cf firebox? Obviously, a person would get some more heat out of the larger unit, but would it be worth the thousands it would cost to make the switch? Would I notice a significant difference in my house? Has anyone made a switch of this kind?

I've had a Hearthstone Clydesdale insert for 5 yrs. 2.4cf firebox...

Thoughts?

You would gain 25% more btu with a 3.0 cf. If a similar stove is used and burned the same way. As also mentioned, thermal blinds work great to minimize nightime heat loss. Look at double and triple cell type. It makes a huge difference.

 

[krex1010]

I believe the Clydesdale can be mounted flush or out 6-8 inches on the hearth if I remember correctly when mounted flush a good portion of the vent that the blower air comes out of is back behind the surround, if you have it mounted in the flush position maybe you can reposition the stove so it is extended out on the hearth. It will expose some more of the stove which will give additional radiant heat and may give you better heat distribution from the blower since the entire vent will be exposed. I only saw this stove one time so maybe I am wrong in my recollection, but if not it may be worth trying before you buy a new stove.

 

[btuser]

More than a larger firebox, I'd like a square firebox. The back of my firebox is about 18", and the front is 24" so in order to fill the stove I'd have to cut my splits in the shape of a trapezoid. I've measured and I stuff about 2cf into my 2.9 cf firebox. Loading N/S I can fit more but the sides are still pretty much empty, and without monster splits I don't get the longer burns because I'm not loading 24" pieces.

 

[60acres]

1) It makes sense that I'd gain 20-25% more heat by going to a firebox that was 20-25% bigger, assuming they had the same efficiency and that I could take advantage of all the space. It's just hard to know how much I'll notice that addition. It's much more than adding nothing, but if it only makes one or two degrees of difference in the room it probably isn't worth it. I suppose that's why some think if you move up from 2.5 cf you should go all the way to 4 cf or so.

2) I put some blankets over the biggest window in the room today. I've caulked carefully around this double paned window from the outside and put weather stripping in. Right now, a pretty typical 15-20 degree morning, it's 65 a few feet in front of the blankets and holding at 47 behind them. Looks a lot like shades would help if I don't mind not seeing out during the day. Either way, they'd help at night. This also has the advantage on not relying on more wood.

3) Yep, the Clydesdale sits out on the hearth and mine is out as far as it can get. I think the claim that this insert can even be used flush is pretty dubious. You can mount it that way, but you'd lose a huge amount of heat.

4) As with your Lopi, I'm always grasping for wood of different lengths when I fill the box. That trapezoidal shape makes you do it if you want to use the space. Comes back to one of the first comments: it might make some difference where the cubic feet are added. I think I'd rather have a couple vertical inches or inches running back to front, rather than than horizontal space, at least once I've got 20 inches across. It's hard to take advantage of all that side to side space.


I'm going to check out some blinds in the next couple of days and go take some real measurements of fireboxes, including my own.

 

[BrowningBAR]

1) It makes sense that I'd gain 20-25% more heat by going to a firebox that was 20-25% bigger, assuming they had the same efficiency and that I could take advantage of all the space. It's just hard to know how much I'll notice that addition. It's much more than adding nothing, but if it only makes one or two degrees of difference in the room it probably isn't worth it. I suppose that's why some think if you move up from 2.5 cf you should go all the way to 4 cf or so.

And with an insert you aren't just relying on radiant heat, but also how well the blower setup works. And just because the fire box in 20-25% bigger doesn't mean it is a usable 20-25%.

If you do get a new stove and only go up 20-25%, every time it's not as warm as you would like it to be you will wonder what it would have been like if you moved up to a much larger firebox.

With a wood stove, I would rather be too warm than not warm enough. Shoot for the biggest stove that will fit in there if you can afford it.