Draft install concerns

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I only rear vent stoves because I like the top to be clear for cooking, heating water, and warming leftovers. And a 6 inch vent is so totally oversized for the tiny Squirrel, in my opinion you won't get any spillage even with rear venting. 6 inch flues work on stoves 4 times larger than a Squirrel.

Greg
If infact the flue is oversized that would make your draft worse leading to more possible spillage and poor performance. To big is just as bad as to small
 
If infact the flue is oversized that would make your draft worse leading to more possible spillage and poor performance. To big is just as bad as to small

That's why Morso put a restrictor in front of the 6 inch collar. It's a very simple clever design that favors the flow out of the stove more than in. I'm glad it's that way because I already had installed 6 inch out the roof years ago. It was also an opportunity to upgrade from black to stainless.

I picked up the factory crated stove from the store, and delivered and installed it myself. The flue cost $400 from Amazon including a cleaning brush and rods. So the complete project of stove, flue, installation, and maintenance kit totalled $1,800.

And old machinist friend of mine used to say when you do something for yourself, you double your money.

Not only do you have the value of the job you did,
you also still have the money in your pocket
that you would have paid to someone else. :)

Greg
 
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That's why Morso put a restrictor in front of the 6 inch collar. It's a very simple clever design that favors the flow out of the stove more than in. I'm glad it's that way because I already had installed 6 inch out the roof years ago. It was also an opportunity to upgrade from black to stainless.

I picked up the factory crated stove from the store, and delivered and installed it myself. The flue cost $400 from Amazon including a cleaning brush and rods. So the complete project of stove, flue, installation, and maintenance kit totalled $1,800.

And old machinist friend of mine used to say when you do something for yourself, you double your money.

Not only do you have the value of the job you did,
you also still have the money in your pocket
that you would have paid to someone else. :)

Greg
I hear you there, we love to work on our house and feel confident tackling a lot of things, but I just don't feel like I have the know-how when it comes to a box of fire ;). Fortunately our installer is only charging about 500 to install. That doesn't seem too much to me to make sure it's done just right.

I'm curious about your flue though, I just compared my installer's quoted pieces to buying them myself on woodland direct and the numbers ended up nearly the same, about 944 for the piping/fittings etc. for how he had spec'd it on the quote.
 
Also, do I need a spark arrestor? I don't think it's on my quote and I'm not sure if it's important or not?
 
That's why Morso put a restrictor in front of the 6 inch collar. It's a very simple clever design that favors the flow out of the stove more than in. I'm glad it's that way because I already had installed 6 inch out the roof years ago. It was also an opportunity to upgrade from black to stainless.

I picked up the factory crated stove from the store, and delivered and installed it myself. The flue cost $400 from Amazon including a cleaning brush and rods. So the complete project of stove, flue, installation, and maintenance kit totalled $1,800.

And old machinist friend of mine used to say when you do something for yourself, you double your money.

Not only do you have the value of the job you did,
you also still have the money in your pocket
that you would have paid to someone else. :)

Greg
If you have a fire in the stove there is really very very little danger of a backdraft. I have seen their "restrictor" and to me it looks like a device to help hold heat in the firebox.

I agree about the whole doing it yourself thing i never pay to have any work done. Even very little on cars. But everyone needs to know their limitations. And a stove and chimney really is not a place to experiment if you are not comfortable in your abilities. There is just to much that can go wrong. That being said for the most part it is not that complicated. If you can simply follow directions well and have a decent understanding of construction tools and techniques most can do it fine. What gets people in trouble is when they are full of themselves and think they know better than the manufacturers code writers ect ect and decide to do their own thing.
 
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It wouldn't necessarily be at all, I'm just trying to gauge how much the back vent makes a difference. Basically can it be compensated for with more chimney height?

I mean, theoretically I could do even a 16' flue, it would just be about 10' of pipe above the roof (is that even ok?)
10 ft is ok, but it will need a second brace or guy wiring due to the extra height.
 
Also, do I need a spark arrestor? I don't think it's on my quote and I'm not sure if it's important or not?
Probably not but that will depend upon local regulations.
 
Probably not but that will depend upon local regulations.
It doesn't appear to be an expensive part...I did find an article claiming it was super important for preventing sparks from getting out and critters from getting in. I guess if it's inexpensive and has no downside it seems a good idea? Or is there any disadvantages?
 
I hear you there, we love to work on our house and feel confident tackling a lot of things, but I just don't feel like I have the know-how when it comes to a box of fire ;). Fortunately our installer is only charging about 500 to install. That doesn't seem too much to me to make sure it's done just right.

I'm curious about your flue though, I just compared my installer's quoted pieces to buying them myself on woodland direct and the numbers ended up nearly the same, about 944 for the piping/fittings etc. for how he had spec'd it on the quote.

There's a simple explanation for that. The ceiling box, double wall through the roof, and the cap were already installed when we built the house. When installing the Squirrel, I only replaced all of the inside pipe. 500 for an install sounds pretty reasonable.

Spark arrestors are good. Get one.

Greg
 
It doesn't appear to be an expensive part...I did find an article claiming it was super important for preventing sparks from getting out and critters from getting in. I guess if it's inexpensive and has no downside it seems a good idea? Or is there any disadvantages?
The only major disadvantage I can see, specifically with your application is how are your going to take the cap off to clean it if the metal mesh gets crusted over? Since you intend on going 10ft above the roof and supporting the chimney with braces / guy wires it would be a project to try and clean the cap, and sometimes they get gummed up, especially if your wood isn't up to par. I'd go with a traditional cap and if a animal problem develops switch to a cap that has the mesh / spark arrestor. Also, animals wont be interest in the chimney unless its cold, if its in use they will stay away, off season is when people have animal problems and those are few and far between.
 
That's what a restrictor does.
It compensates for a large flue.
But that doesnt make sense. A larger flue will reduce the velocity of air moving out of the stove. So a restrictor would be the last thing you wanted. There is allot more to sizing a flue properly to match a stove than firebox size. I am pretty sure moroso knows what they are doing and the 6" is correct.
 
It doesn't appear to be an expensive part...I did find an article claiming it was super important for preventing sparks from getting out and critters from getting in. I guess if it's inexpensive and has no downside it seems a good idea? Or is there any disadvantages?
To be clear an animal screen and a spark arrestor are not the same thing at all. A screen is usually 3/4 or 5/8 mesh. While a spark arrestor is 3/8 at most.
 
But that doesnt make sense. A larger flue will reduce the velocity of air moving out of the stove. So a restrictor would be the last thing you wanted. There is allot more to sizing a flue properly to match a stove than firebox size. I am pretty sure moroso knows what they are doing and the 6" is correct.

Morso does know what they're doing. That's why they added the restrictor to compensate for a large flue on a really tiny 7/10th cubic foot firebox. The stove performs very poorly without it. I know because I burned it with the restrictor removed to find out for myself. I'm really glad they put a 6 inch collar on their stove because 6 inch flues are standard on most stoves here. Sure helped me simplify my installation.

Here's the UK specs. It comes with a 5 inch collar over there.

Morsø 1410
Output 4.5kW (1410)
Construction cast iron, ceramic glass
Flue Outlet top and rear
Flue Size 125mm (5″)
Grate Type multifuel grate

Greg
 
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Morso does know what they're doing. That's why they added the restrictor to compensate for a large flue on a really tiny 7/10th cubic foot firebox. The stove performs very poorly without it. I know because I burned it with the restrictor removed to find out for myself. I'm really glad they put a 6 inch collar on their stove because 6 inch flues are standard on most stoves here. Sure helped me simplify my installation.

Here's the UK specs. It comes with a 5 inch collar over there.

Morsø 1410
Output 4.5kW (1410)
Construction cast iron, ceramic glass
Flue Outlet top and rear
Flue Size 125mm (5″)
Grate Type multifuel grate

Greg
Yes but what i am saying is that is not to restrict the draft because of an oversized flue. An oversized flue will give you less draft not more.
 
Yes but what i am saying is that is not to restrict the draft because of an oversized flue. An oversized flue will give you less draft not more.

I discovered the reason for the added restrictor when Morso went from a 5 to a 6 collar by actually burning my own stove without it. The stove loses way too much heat to the larger flue because the larger flue has more draw.

Trying to argue theory against actual results is powerless to alter the reality of those results.

This is why I go by what actually happens by finding out for myself. ;)


Greg
 
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I know the reason for the added restrictor when Morso went from a 5 to a 6 collar because I found out for myself by actually burning my own stove without it. The stove loses way too much heat to the larger flue because the larger flue has more draw.

Trying to argue theory against results can't change what actually happens. ;)


Greg
And if you pull the baffle out of any stove it will send to much heat up the stack. That doesn't mean the flue is oversized. It means when you change a stove from its design it doesnt work as well. And btw i am not arguing theory i am pointing out the actual physics an oversized flue does not increase draft. It increases volume but decreases velocity. That decrease in velocity allows the flue gasses to cool more and reduces draft. To small of a flue reduces volume to a point that not enough air moves through the stove and the fire is to cool. Your stove was obviously designed to run on either 5 or 6 and they adjusted the stove to run on 6 that does not mean that 6 is oversized. Or that the op can get away with a short chimney. His stove will work completly different that yours because of the difference in the height of the chimney the difference in the pressures in the houses. The diffetence in elevation ect. So you experince with your stove in your house doesnt nessecarily mean much about his stove in his house. That is why I rely on physics and the experince working on and running many different stoves in many different houses to know what will work.
 
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You're trying too hard.

Greg
Never mind i dont know why i bother trying to teach you anything. You obviously know more than those of us that do this every day for a living.
 
The only major disadvantage I can see, specifically with your application is how are your going to take the cap off to clean it if the metal mesh gets crusted over? Since you intend on going 10ft above the roof and supporting the chimney with braces / guy wires it would be a project to try and clean the cap, and sometimes they get gummed up, especially if your wood isn't up to par. I'd go with a traditional cap and if a animal problem develops switch to a cap that has the mesh / spark arrestor. Also, animals wont be interest in the chimney unless its cold, if its in use they will stay away, off season is when people have animal problems and those are few and far between.
If I'm planning on a sweep cleaning/checking the whole thing once a year before burning season, would he do the cleaning of the mesh/cap?
 
Yes, the sweep should clean the cap screen. Burning dry wood will keep it pretty clean by itself.
 
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To be clear an animal screen and a spark arrestor are not the same thing at all. A screen is usually 3/4 or 5/8 mesh. While a spark arrestor is 3/8 at most.
Does a spark arrester really work? Sparks on the rubber roof or asphalt roof would obviously be a real concern :)
 
Never mind i dont know why i bother trying to teach you anything. You obviously know more than those of us that do this every day for a living.
Lets not fight, I don't want to get my mom jeans on :) Hahahaha, I think both of you may be saying the same thing in different ways :) My UNDERSTANDING from this thread (I might be wrong) is that restrictor thing Morso includes is for improving the draft by making the opening smaller. Much like putting your thumb over a hose makes the water come out faster?
 
More likely it is to slow down draft a bit to keep the firebox hotter for a cleaner burn to meet EPA requirements. Maybe contact [email protected] with Morso specific technical questions?
 
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