New VF100

docsj125

Member
Dec 25, 2016
13
Wolcott Ct
Bought a VF100 .I an in the process of removing my SJ125 and installing the VF100.
On my old furnace I had the chimney straight up from the back of the furnace but I can install VF 100 the same way because of the return air inlet.
The way I want to install it will require a 90 out the back of the furnace and two 45 with about 6 ft of black stove pipe to the chimney.
Is this too much angle?Would it affect my draft?
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,529
NE Ohio
Congrats on the new VF, you'll love it! I had a BJ90 and a Husky wood/oil before wising up.
Anyways, how tall is your chimney? Is it masonry (if so, flue ID?) or SS?
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,529
NE Ohio
Ok, so that should draft decent...so tell us about these bends....90 up, or to the side? And how much rise will there be on the runs? (how much height difference between VF and chimney connection?) Pics might help...
 

docsj125

Member
Dec 25, 2016
13
Wolcott Ct
IMG_9757.jpg

A 90 out to the side about a ft of pipe then a 45 and about 6ft of pipe and a 45 to the chimney.There is about 30" height difference between furnace and chimney connection.
I am only using this pipe as a mock up.
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,529
NE Ohio
Boy, that's a tough one...how close to the VF will the pipe be then? Not sure which side you will be on, but I would keep the pipe well away from the computer...actually, I would use doublewall stove pipe...that will help with the draft by keep the flue gasses hot, and run cleaner too...also, the inner wall is stainless, so it lasts much longer than plain steel, or even galvanized pipe (which isn't really supposed to be used for stove pipe on a wood burner, due to the galvanizing off-gassing a poisonous gas if overheated...which should never be an issue on the Kuuma) Also, if you use doublewall, get a telescoping piece, it makes taking the pipe apart to clean much easier, although with all the bends you have there, getting it apart may not be an issue.

So there is no way of moving/adapting the return air duct to make the stove pipe less complicated? Assuming it must be behind where the VF is sitting now?
Many people don't even hook the return air/blower box up to a duct...
 

docsj125

Member
Dec 25, 2016
13
Wolcott Ct
Boy, that's a tough one...how close to the VF will the pipe be then? Not sure which side you will be on, but I would keep the pipe well away from the computer...actually, I would use doublewall stove pipe...that will help with the draft by keep the flue gasses hot, and run cleaner too...also, the inner wall is stainless, so it lasts much longer than plain steel, or even galvanized pipe (which isn't really supposed to be used for stove pipe on a wood burner, due to the galvanizing off-gassing a poisonous gas if overheated...which should never be an issue on the Kuuma) Also, if you use doublewall, get a telescoping piece, it makes taking the pipe apart to clean much easier, although with all the bends you have there, getting it apart may not be an issue.

So there is no way of moving/adapting the return air duct to make the stove pipe less complicated? Assuming it must be behind where the VF is sitting now?
Many people don't even hook the return air/blower box up to a duct...
Thank you so much for you input.
I can try to install it so the chimney is directly over it.
Ill have to figure out the return duct.
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,529
NE Ohio
Thank you so much for you input.
I can try to install it so the chimney is directly over it.
Ill have to figure out the return duct.
Where is the return duct from where things are in that picture?
Some people get away with not hooking the return up, but if you have a cold basement, know that it will affect your plenum/supply duct temps somewhat...some have had good luck with pulling return air from more so up by the ceiling, instead of off the floor...
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,529
NE Ohio
Is the vf so different from the old furnace that you have to move it across the room?
The Jack series Yukons had the blower coming in the side...VF is in the back
 

brenndatomu

Minister of Fire
Aug 21, 2013
5,529
NE Ohio
Ah, SJ = super jack. Remember crappie Keith?
Yup, talked with him on the phone a few times...he sure believed in his product...wonder what ever happened to him?!
He was basically the reason that I tried 2 different Yukon products! :rolleyes:
The back and forth between him and Lamppa over on AS sure was entertaining back in the day! ;lol
 

laynes69

Minister of Fire
Oct 2, 2006
2,515
Ashland OH
Lol.....I've had it out more times than I can count. Pretty much though, I called it knowing what would happen to the company. Whew the memories!
 

RockyMtnGriz

Member
Apr 19, 2019
87
SW Montana
I see you've done a lot of sealing. So have I. I found it very productive to seal the gap around the front cover above the door. The very hottest air in the stove leaks from that gap. It really helped me with delivering heat to the far end of the house.

Nice job!
 
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brenndatomu

Minister of Fire
Aug 21, 2013
5,529
NE Ohio

RockyMtnGriz

Member
Apr 19, 2019
87
SW Montana
How did you seal it?
I used Permatex Ultra Black silicone to create a formed-in-place gasket. It's attached to the cover side. It doesn't cause any issues with removing or replacing the cover, and it eliminated 99% of the leakage.
 
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JRHAWK9

Minister of Fire
Jan 8, 2014
1,501
Wisconsin Dells, WI
FWIW, I was told those small gaps on the front panel are done on purpose. That's an area of not much air flow and high temps. Those gaps are there to create some air flow past the area to help transfer some of the heat away from the front of the furnace in that area. This came from Daryl, the owner.
 

RockyMtnGriz

Member
Apr 19, 2019
87
SW Montana
Ok, the discussion of sealing the front of the stove is getting a life of it's own, and I realize that I haven't stated the detail of not sealing the front cover of the stove to the body of the stove with silicone. DO NOT DO THAT!! What I'm talking about is making a gasket that builds up the front cover to seal the gap to the stove body. I did this by putting a bead of silicone on the cover only that is slightly taller than the gap at each point. It needs to be lower at the bottom, and taller near the top, wherever there is a significant gap. Then overlay that with wax paper strips and gently return the cover to place. Let it set up very well - 24 hours if you can stand it, and voila, you have a REMOVABLE gasket that matches the contour. It'll be stuck to the cover, but not the stove. The wax paper will stick to the silicone, but you can trim most of it off and the rest will go harmlessly to dust from the heat. An alternative to the wax paper would be some viscous hand or dish soap applied to the body of the stove to keep the silicone from sticking. I think the wax paper is better in this case, since there's a bit of sliding contact when you put the cover on to form the gasket, but it doesn't hurt to use a little soap on the stove body if there is an area where you think the silicone might squeeze out and touch the stove body around the wax paper. If you use the right amount of silicone, you'll end up with a 1/4 to 3/8 flat top, and it wont squeeze out so it's visible with the cover installed.

Sorry for all that. I just don't want to own somebody's grief from them gluing their pretty new furnace into a solid block that they'll need a hammer and chisel to open for maintenance.

JRHAWK9
I talked to Daryl about this too. It was kind of an aside to one of the conversations about water heating we had. He was interested in the details of how I did it, but never mentioned anything about the gaps being intentional... I'll leave it at that. That is the hottest part of the stove, at least in the normal configuration with the baffle installed over the burn chamber, but from what I've seen, there's pretty decent air flow there. I did a lot of probing and temp taking during my water heating project, and that's the air flow I've harnessed into my DHW heat exchanger. I can tell you that the air coming out of that area runs about 165-185 with the fan on and the gaps sealed, so regardless, we're not talking smoking hot.

It's easy to seal those gaps, and it made a significant difference in the delivered air temp, as well as a noticeable difference in heat performance at the hard-to-heat ends of my house. It also made a large difference in the temp of my furnace room, in spite of the fact that I have a return air intake in there. If you have trouble moving heat around the house, like I do, you might try finding your best heat resistant stuffing for those gaps and see if it helps you. But, laying a bead of silicone along that gap to make a permanent gasket, is probably easier than trying to chink those gaps with something. It just requires a not-hot stove for at least 8 hours until it hardens up.
 
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JRHAWK9

Minister of Fire
Jan 8, 2014
1,501
Wisconsin Dells, WI
JRHAWK9
I talked to Daryl about this too. It was kind of an aside to one of the conversations about water heating we had. He was interested in the details of how I did it, but never mentioned anything about the gaps being intentional... I'll leave it at that. That is the hottest part of the stove, at least in the normal configuration with the baffle installed over the burn chamber, but from what I've seen, there's pretty decent air flow there. I did a lot of probing and temp taking during my water heating project, and that's the air flow I've harnessed into my DHW heat exchanger. I can tell you that the air coming out of that area runs about 165-185 with the fan on and the gaps sealed, so regardless, we're not talking smoking hot.
You know what, I was just in that area to clean my HX tonight. I bet what he was referring to was those larger than needed rectanglar holes that the "fingers" of the front cover slide into. I bet those are what he was referring to as being larger than needed to get some air to the front of the body under the cover.
 
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RockyMtnGriz

Member
Apr 19, 2019
87
SW Montana
You know what, I was just in that area to clean my HX tonight. I bet what he was referring to was those larger than needed rectanglar holes that the "fingers" of the front cover slide into. I bet those are what he was referring to as being larger than needed to get some air to the front of the body under the cover.
Yeah, that makes perfect sense, Those holes are an order of magnitude larger than they need to be, given the tolerances they hold in constructing these stoves. Their position also would help tie the high air pressure, sides of the stove, to the front cover area.

They have the side benefit of making the front cover easy to install, even after you've consumed the number of beverages needed to get through a good cleaning; without deciding to pursue an alternative activity, before finishing the cleaning task. :)