Everything Drolet Tundra - Heatmax...

[DoubleB]

Thanks 46Z. It's serving me well so far. Kudos to Brenndatomu for starting this thread, hopefully we can all get good ideas from others. I know I am.

 

[TheBigIron]

Thanks 46Z. It's serving me well so far. Kudos to Brenndatomu for starting this thread, hopefully we can all get good ideas from others. I know I am.

B

What are your thoughts on insulating my ss chimney liner??

 

[DoubleB]

I was mum because I'm no authority on chimneys and my Dwyer manometer is on order so I haven't verified my drafts yet.

My 37' uninsulated SS liner is 6" diameter, down my masonry chimney. From what I can tell, I have too much draft, if anything. My baro damper seems to either be closed (no fire), or full open (fire). Again, I look forward to measuring my actual drafts to see if my baro is too light. But I can easily get a roaring fire so I don't think I'm lacking draft even with baro wide open.

I also have two 45-deg elbows connecting the Tundra to my chimney, about 5 feet away, so little flow restriction there.

I've only cleaned my chimney once, after 5 weeks of burning, and I really probably didn't need to. I got a few cups of black flaky stuff, no glossy hard stuff except the top foot at the chimney cap. That was 2+ months ago, I should do it again just to get a feel for it's tendencies. I have no experience with an insulated liner inside a masonry chimney, but I think those guys say they have very little creosote. However, I wonder if that's just because they're burning really good wood? My wonder is because, if I can put my hand on the exhaust at my furnace because it's so cool, I would guess that either insulated or uninsulated would both be similarly quite cool to condense any creosote that escapes the furnace.

I went uninsulated mainly because my chimney sweep said I wouldn't need insulated, and he said there was hardly any room to add insulation anyways.

I think Laynes has said he's got a 28' insulated chimney, so he's in the same ballpark as you are too.

So, based on my experience, I think you'd be fine uninsulated with minimal elbows. I look forward to other people's input.

 

[brenndatomu]

I'm going to start with my chimney and going to drop a ss liner down it. My question is since my chimney is in the middle of my home and receives heat from the house except for maybe 12', should I insulate the liner or not. Chimney total length approximately 30'. thanks for your input

Hmm, that's a good question. Normally they say if the chimney is inside the house and structurally sound that you don't have to insulate but it is still a good idea because there is no way to know if it was really built properly as far as clearance to combustibles. Also, unless you have had a sweep come in and give the full length of the chimney a camera inspection it is still a good idea to insulate just because you never know where a crack is starting. You and your family are going to bed with a fire in the house you know...respect the fire.
I'd insulate the full length...

 

[joes169]

I only have about 20' of chimney (low roof pitch, single story) and only about 2' of my chimney is above the roof line. Also, I had an 8.5" by 13" flue, so I had plenty of room left. I wasn't sure the best way to actually "hang" and stabilze the liner (I really didn't want it hanging on the tee, and didn't want to rely on the flashing collar on top) so I simply mixed up what's called "insulating castable" and poured it around the top 3' or so of the flue, which is likely cool the fastest. It makes the pipe nice and solid, and the stuff is lean enough that I could always get it out if I had to replace the liner or something.

 

[Wisneaky]

I wanted to share something. I have one of the first couple hundred Tundra's made. A couple weeks back I was at Menards and noticed on the new Tundra's the damper door was redesigned. I emailed SBI and they sent me the new door. It comes with some sort of shiny metal insert and the new door. The new door is redesigned in a fashion that when it closes it stays open partially thus always letting in some air. Here are some pictures of the old and new.

 

[DoubleB]

I have one of the first couple hundred Tundra's made. A couple weeks back I was at Menards and noticed on the new Tundra's the damper door was redesigned.

Interesting--I have a recent Tundra (June 2014, post ash-drawer) yet it doesn't have the shiny metal insert that you show in your last two pictures. Any word why the change?

Do you happen to recall if the unit you saw at Menards also had the damper cracked open? I was down their aisle recently and don't recall seeing the damper cracked open.

Edit: On second thought, maybe the shiny part is only needed for retro kits, and newer furnaces are inherently designed with whatever air holes are needed.

Do you notice a difference in your furnace performance now?

 

[Wisneaky]

Interesting--I have a recent Tundra (June 2014, post ash-drawer) yet it doesn't have the shiny metal insert that you show in your last two pictures. Any word why the change?

Do you happen to recall if the unit you saw at Menards also had the damper cracked open? I was down their aisle recently and don't recall seeing the damper cracked open.

Edit: On second thought, maybe the shiny part is only needed for retro kits, and newer furnaces are inherently designed with whatever air holes are needed.

Do you notice a difference in your furnace performance now?

I'm not sure why they changed it. I honestly don't remember if the one at Menards was cracked open, but I know it did have the shiny insert. I just installed it so I'm not sure if their is any performance change yet.

 

[DoubleB]

Well I finally got a manometer hooked up. Draft measures at 0.05 inH20, supposed to be 0.04 to 0.06. I'm probably just lucky, but I had adjusted the baro damper over the last few months to get what I thought appeared to be an appropriate fire, so I'm happy with that. I'll keep checking on warm calm days and really cold and windy days.

Then, I measured pressure in my ducts. I'm using slow (900 cfm) speed. I found that my supply plenum is at +0.08 inH20, which I understand suggests I designed my supply well enough. I also measured my cold return on the upstream side of the air filter, it was -0.07 inH20, again I believe that's a good number. (I made a separate duct system for the Tundra, separate from my LP furnace).

I was all happy until I measured 1" later on the downstream side of the filter, and found it was -0.30inH20. If that's right, that means that my blower is producing a total of 0.37 inH20, 0.15 of which (40%) is to move air through the ducts, and 0.23 of which (60%) is just to move air 1 inch through the filter. I oriented the probe both parallel and perpendicular to the airstream, with similar results.

It's a new filter, and in fact has 8% more surface area because I'm using a 16x20 instead of the original 15x20. It's just a plain pleated MERV7 filter from Menards.

I was just so surprised that the filter consumed most of the pressure the blower produces. Is this normal? Am I missing something here?

At a minimum, I can see why the Tundra manual tells us to remove the filter in a power outage.

 

[JRHAWK9]

A higher MERV filter rating will do that. You just need a cheap filter like -THESE-

Doesn't the Tundra manual call for 0.2" - 0.5" of static pressure on the supply side?

 

[Wisneaky]

Tundra supply should be .2 inh2o

 

[DoubleB]

I recall the manual said 0.2 inH20 in a way that wasn't very clear relative to what. For example, 0.2 inH20 in the supply but no filter or cold air ducts represents a much higher airflow than my 0.07 inH20 in the supply and -0.30 inH20 suction after my filter and cold air duct. In other words, I don't understand supply pressure alone to mean much from the furnace's vantage point, as long as the supply air is not too hot indicative of failing to have enough air to carry heat away from the furnace. I seem to be getting plenty of airflow, since even with a raging fire my air temperatures have a hard time reaching 125-130F.

Or, said yet another way, I pulled the filter just now and measured about 0.10inH20 supply about about -0.10inH20 return air. That's the same as 0.20inH20 supply in Tundras that don't use return air ducts. So if I used a cheap MERV2 filter like JRHAWK linked, I'd be getting the same airflow as one can conceive the manual calls for.

Please tell me if I'm off on something.

 

[JRHAWK9]

Everything I have read said that a typical HVAC system shoots for a total static pressure of 0.5" - 0.75". So 0.35" supply and -0.2 return would fall into this. I have no idea if it's correct, it's just a common range in which seemed to have come up while doing some searching online. My static pressure is around 0.3" supply on my Kumma. The main reason for wanting decent static pressure in the supply side of a wood furnace is to slow the air down some to allow it to get heated before moving into the duct. I'd think if you are getting good heat out of your ducts with low static pressure, then I don't think it's an issue. Although I could be completely wrong.

 

[Wisneaky]

I talked with an SBI tech on the phone a while back about the static pressure and he told me that the supply side should be .2 inH2o with or without a filter. You'd just need to adjust blower speed and or trunk size to get it that that reading.

 

[STIHLY DAN]

Pressure is pressure. if it calls for .2 in the supply then that's what you want your reading to be. If its plus 2 in the supply then it should be around -2 on the return. You can turn your fan up or turn down some of your balancing dampers. I would increase fan speed so there is more flow on an outage.
Re-reading your numbers, your unit has to be losing air before your supply reading. I understand these are VERY leaky units, many people had to do serious air sealing on the UNIT to get there press right.

 

[DoubleB]

Thanks guys, makes sense. Then the 0.20" spec in the manual must be SBI helping us get equal flow out of our supply registers, and have nothing to do with removing heat from the furnace. I suspect that because otherwise the manual would have a max allowable pressure across the blower. If the manual says it's ok to operate at low speed with 0.20" in the supply plenum, then I can only have more total airflow if my entire pressure drop (with lighter filter) in the system is less than that. And I'm more interested in adequately removing heat from the furnace than in equal flow out of all registers. House is warm, no fuel bills, wife is happy, I'm happy...

I did put aluminum tape to connect the blower discharge to the housing, and on a couple other places that were leaking air. I can still feel air leaking in a few places, but nothing too much.

Last weekend for fun in the middle of a small fire I cut power and pulled the filter for 1/2 hour. I was impressed by the air volume pushing out the registers, and the air wasn't too hot. That's important to me, so I was pleased.

When the HVAC guy replaced my oil with LP furnace, he had measured a 0.34" total gain across the blower (cold return to supply plenum) and had said nowadays they shoot for 0.20". I also thought I had read the same a few places, so that is what I was shooting for. Maybe I was mistaken, and it is supposed to be a 0.20" goal for the supply plenum only. Since then the HVAC guy has been wrong more than once too.

Another question: how loud would you describe your system? Mine is loud enough that we couldn't keep the TV super quiet if the kids were sleeping, without missing quiet dialog some of the time. That example is part of the reason I went to low speed, that helped reduce noise a little bit. I'd like to make it even quieter if I can.

 

[Wisneaky]

Thanks guys, makes sense. Then the 0.20" spec in the manual must be SBI helping us get equal flow out of our supply registers, and have nothing to do with removing heat from the furnace. I suspect that because otherwise the manual would have a max allowable pressure across the blower. If the manual says it's ok to operate at low speed with 0.20" in the supply plenum, then I can only have more total airflow if my entire pressure drop (with lighter filter) in the system is less than that. And I'm more interested in adequately removing heat from the furnace than in equal flow out of all registers. House is warm, no fuel bills, wife is happy, I'm happy...

I did put aluminum tape to connect the blower discharge to the housing, and on a couple other places that were leaking air. I can still feel air leaking in a few places, but nothing too much.

Last weekend for fun in the middle of a small fire I cut power and pulled the filter for 1/2 hour. I was impressed by the air volume pushing out the registers, and the air wasn't too hot. That's important to me, so I was pleased.

When the HVAC guy replaced my oil with LP furnace, he had measured a 0.34" total gain across the blower (cold return to supply plenum) and had said nowadays they shoot for 0.20". I also thought I had read the same a few places, so that is what I was shooting for. Maybe I was mistaken, and it is supposed to be a 0.20" goal for the supply plenum only. Since then the HVAC guy has been wrong more than once too.

Another question: how loud would you describe your system? Mine is loud enough that we couldn't keep the TV super quiet if the kids were sleeping, without missing quiet dialog some of the time. That example is part of the reason I went to low speed, that helped reduce noise a little bit. I'd like to make it even quieter if I can.

My tundra is in the basement so the only place you can hear it in my house is in the kitchen because there is an old air return grate in the floor there. My kids are used to noise though. We can crank our TV up and it doesn't bother them.

 

[Smoke Signals]

Ok, I just found out in another thread that a hot water coil is an option for the Kuuma (thought I had been told otherwise). Any one know if it is an option for the Tundra? Thanks

 

[brenndatomu]

Ok, I just found out in another thread that a hot water coil is an option for the Kuuma (thought I had been told otherwise). Any one know if it is an option for the Tundra? Thanks

SBI doesn't offer one that I know of. I suppose you could cob an aftermarket coil in if you were determined...
Doesn't look like a factory option on the Caddy either...

 

[davidon]

My tundra is in the basement so the only place you can hear it in my house is in the kitchen because there is an old air return grate in the floor there. My kids are used to noise though. We can crank our TV up and it doesn't bother them.

Need additional input about the noise level from the unit. I am considering getting a unit to put in an unfinished basement however the basement will be finished off and someone will be living there. Is the noise level too loud for someone to be occupying the same area?

 

[Wisneaky]

Need additional input about the noise level from the unit. I am considering getting a unit to put in an unfinished basement however the basement will be finished off and someone will be living there. Is the noise level too loud for someone to be occupying the same area?

I'd say no. I frequently talk on my phone when I'm in the basement and have no issues hearing the caller on the other end when the blower is going.

 

[STIHLY DAN]

I take a nap as often as I can, with my head about 3 ft away from my furnace. But I don't have a tundra.

 

[DoubleB]

Mine is loud enough that we couldn't keep the TV super quiet if the kids were sleeping, without missing quiet dialog some of the time.

Hope I didn't cause undue alarm. I'd say my Tundra is a bit quieter than the new high efficiency LP furnace they installed last fall, 90,000 Btu/hr. (Which, however, isn't as quiet as I was expecting). I'd also say the Tundra is quieter than the oil furnace I had taken out.

 

[davidon]

Hope I didn't cause undue alarm. I'd say my Tundra is a bit quieter than the new high efficiency LP furnace they installed last fall, 90,000 Btu/hr. (Which, however, isn't as quiet as I was expecting). I'd also say the Tundra is quieter than the oil furnace I had taken out.

Thanks for the input guys. Other question is it seems like the Tundra takes a lot more tweaking to get it set up right compared to the Kuuma. Is this correct?

 

[brenndatomu]

Thanks for the input guys. Other question is it seems like the Tundra takes a lot more tweaking to get it set up right compared to the Kuuma. Is this correct?

I would say no. It is just that there are a ton more of them out there and they are marketed toward the DIY crowd so you just hear more about the issues. The Kuuma guys are talking with Kuuma over the phone to sort out their issues.