The whole deal for a basement wood furnace

[roofyroo]

I had a thread on the Hearth Room and was suggested to post in here as my solution is moving towards a wood furnace in my basement.

Previous thread link.
https://www.hearth.com/talk/threads...r-relocate-my-wood-stove.140210/#post-1885613

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Relevant furnace info from original post doing Option 5
I'm in Virginia and recently bought a 2 story 2000 sq. ft. house with a basement (additional 1000 sq. ft.) built in 1933. The previous owners left a Hearthstone Heritage 8021 wood burning stove which is located in a corner room of the house which was clearly an additional at some point. This room has a chimney flue as well the 2 flues in each side of the open basement.
The old owners just upgraded their heating system but it is all electric and clearly the unit is not capable of keeping up in the cold - hence the electric bill is sky high - so I'm investigating options.

5. Buy a wood burning furnace, install in the basement, hook it into the HVAC. This option will mean lining one of the chimney's for exhaust.

From my morning's research I understand lining a chimney is not difficult, and several experts over the phone suggested the Z Flex liner. I went up on my roof and checked things out and my chimney flue is approximately 27' so the 30' kit would do.
http://www.supplyhouse.com/Z-FLEX-2ZFLKIT0630-6-x-30-FT-All-Fuel-Stainless-Steel-Liner-Kit
MyRubberNeck says the kit comes with a Long Snout Flex Ready Tee
SupplyHouse says the kit comes with a Stacking Tee
I believe these are both the same but worded differently?

I see that pretty much everyone recommends insulation of the lining if using for wood, and I found this, also from Z Flex - 25' x 6".
http://www.supplyhouse.com/Z-FLEX-2INSKIT0625-6-x-25-Ft-Insulating-Blanket-w-Wrap-Gear-Clamps
Would I really need to purchase an additional 2' of this so my entire chimney is lined with insulation?

Total for chimney lining and insulation.
MyRubberNeck - $1015
SupplyHouse - $868

I wanted to stay below $2000, but if this is a longer term investment then I don't mind going over a little.

#1 recommended is the Drolet Tundra

I had also asked about these below?
Englander 3000
US Stove Hot Blast 1400 or 1500
Vogelzang Norsemen 2500

Someone quoted on top of the chimney liner, insulation and furnace - "there will need to be one or two back draft dampers installed. add maybe $1000 for the additional sheet metal fabrication and installation"

Thanks

 

[maple1]

I only see one question in there, on the Ts - and I don't know the answer, have no experience with liners at all.

But if it was a question further down - I would pick the Tundra over the other 3 you mention, even if the others are a bit cheaper. There was a nice post showing a good Drolet installation in another thread earlier today or yesterday - should be able to find it, it's not down the thread list very far, forget which one it was now. Had good info on dampers too.

EDIT: https://www.hearth.com/talk/threads/hooking-up-a-drolet-tundra.138994/

 

[roofyroo]

Thanks for responding, and no, I didn't really ask a question. I was just looking for input.

The 3 other units I mentioned are $600 less. I'd love to get what everyone is recommending but the total cost for this whole install will add up to too much. The next cost I'm trying to figure out is the additional material.

Here is the chimney flue we'll use and the current forced air furnace next to it.
(broken link removed)

I checked out the other link for the Drolet install. Our house is old and has no cold air return. Not great I know, but thats the way it is for now. With that in mind would all I need to do is hook the double vents into the plenum with back draft dampers, and the exhaust the chimney flue? I don't believe there is anything else?

 

[brenndatomu]

The 3 other units I mentioned are $600 less.

And all but the Englander are actually worth $1200 less, and that's being generous. Hot Blast and Norseman are chimney plugging wood hogs.
Hopefully you didn't just miss seeing the $1250 sale Menards was having last week on the Tundra, still on sale for $1400, which is still a really good price. You'd have another ~$300 or so in shipping since there are no Menards around you.
You can probably tie in using prefab round duct work and DIY, save a TON of $. Should be way less than $1k.
Shop around on the chimney liner, Rockford, Chimney Liner Depot, Woodland Direct, there are many others. Don't over think a liner, they all hafta meet the same regs. No sense spendin big $ on "gingerbread" IMO. Get a SS liner made for wood burning, insulation kit from the same company, tee kit, top cap, git 'er dun. Heck, I'd say a chimney liner kit and your duct work shouldn't be much more than $1k all total.
You'll need an additional thermostat ('cept the Englander), like a FocusPro 5000 works good for wood burning furnaces. Can be bought $20 or less on fleabay if you shop a bit. Half dozen on there right now less than $15 delivered.
Sounds like you have a pretty handle on the basics of what you'd need.

 

[roofyroo]

If I'm looking at the Tundra for say $1800, then are you saying these 2 units (US Stove Hot Blast 1500 OR Vogelzang Norsemen 2500) are worth about $1200 less - i.e. they aren't worth much at all? Anyone else have an opinion on this? Just because I see good reviews about all of them.

All the chimney liner kits state that is burning wood then they should be insulated. I want to make sure that what I'm putting in is safe, so buying the 30' liner for my 27' chimney, and then buying the 25' insulation should be enough? I don't need to insulate the top 2', or do I need to buy 2' more?

I haven't looked at round duct work yet but should I assume that I buy roughly the right size including the bends (elbows or whatever you call them) and then cut into the havoc with steel cutters and then seal with foil tape?

Looking at my basement photo I was going to place the furnace to the left of the current furnace?

 

[brenndatomu]

I see good reviews about all of them.

Use the search feature on here and over on AS, there aren't too many people that like them after they have them a while. Most hate 'em. Do a CL search there are a TON of these kind of wood furnaces for sale. I know the Tundra hasn't been around as long but I haven't seen a used one for sale yet. Quite a few owners here and on AS, pretty well liked. I can only recall 1 guy that didn't like his Tundra, but he had the first model year problems and I personally think he had caused some of his own too. Very little to no customer service with the other two models, but Drolet is well thought of in that regard. Any other real issues have been initial setup problems or operator learning curve. Heck, I just ordered one for my sister to replace her wood hog smoke dragon.

I don't need to insulate the top 2', or do I need to buy 2' more?

The top needs the insulation the most, the flue gasses are the coolest there and the chimney is completely exposed there too. So you have a full 27' from breech to chimney cap? It shouldn't be much more for a few extra feet of insulation. The last liner I bought they threw in some extra "scrap" pieces for free. It actually ended up being quite a bit of material.

I haven't looked at round duct work yet but should I assume that I buy roughly the right size including the bends (elbows or whatever you call them) and then cut into the havoc with steel cutters and then seal with foil tape?

Yep, more or less

Looking at my basement photo I was going to place the furnace to the left of the current furnace?

That should work as long as minimum CTC (recommended minimum clearance to combustibles) is met

 

[maple1]

This is one time I would not go for the cheapest thing - I would buy the Tundra over the rest of those, no doubt. You will be stuck living with whatever you get, long after the initial purchase cost - well worth the extra cost in this case, I would say. Granted that's without having no direct experience with any of them, but some trends develop & come through loud & clear if you do enough reading from people that do have the experience. I can indirectly relate though after living for 17 years with an inefficient boiler, and into 3 now with a good one - best $15k I ever spent, even if I haven't fully recovered from that hit yet.

 

[Buzz Saw]

I've got a hot blast....for now. It gets the job done but eats wood. I only bought it b/c it was cheap on CL. I wouldn't do it if I was stsying in this house for the long haul.The Hot blast is staying with the house when it sells this Spring. I'll be upgrading to something else, can't wait!

 

[roofyroo]

I went with all this in the end and installed it myself. Actually pretty easy after spending time to research and understand the system - and some advice form people on here.

Drolet Tundra (from Menards $1400 + $300 shipping to VA)
Z-flex 30ft chimney liner kit + 30ft liner insulation because I'm burning wood - $950
High temperature black duct for the chimney exhaust and standard silver duct for the 2 connections to the HVAC, few packs of self drilling screws, foil tape, high temp caulk ~ $150

Need to do some additional work covering the chimney and also hook in the two hot air outlets into the HVAC.

Do I really need to install back draft dampers on the duct into the HVAC?

(broken image removed) (broken image removed) (broken image removed)

 

[STIHLY DAN]

No BDR?

 

[brenndatomu]

Do I really need to install back draft dampers on the duct into the HVAC?

Chances are, yes. Try it and see if the gas(?) furnace plenum gets warm below where you tie in, if it does then you need a damper.

No BDR?

As dan says, with a chimney that high, you WILL need a flue damper, a manual key damper, or a BDR, maybe both

 

[maple1]

Chances are, yes. Try it and see if the gas(?) furnace plenum gets warm below where you tie in, if it does then you need a damper.


As dan says, with a chimney that high, you WILL need a flue damper, a manual key damper, or a BDR, maybe both

Then you get to the point of adjusting them for proper draft. Dwyer MarkII Model 25 highly recommended for any furnace owner.

 

[STIHLY DAN]

Do I really need to install back draft dampers on the duct into the HVAC?

If you are going to use wood heat only you can just tape a piece of cardboard to your filter grill.

 

[roofyroo]

The Tundra manual says not to attach a damper to the exhaust.

The plenum get warm below the tie in points. If I turn on the fan on our HVAC then the tie in ports cool down as the Tundra blower will not kick in. I need to hook in the 2 back draft dampers when they arrive and see if that helps.

We have an old house, so a lot of duct that maybe isn't laid out as efficient as it should be. I've changed the Tundra fan to max to blow as much air through as possible - but not doing too great yet.

Should I try and have our HVAC fan on as well, as long as the back draft dampers are installed?

Thanks

 

[brenndatomu]

The Tundra manual says not to attach a damper to the exhaust.

The TUNDRA furnace must be connected to a factory built chimney as per UL 103 HT or
ULC S629 for wood heating appliances, we recommend that the connecting pipe and
chimney have a 6" inside diameter. The minimum draft required at all times is -0.04 in.
W.C. but the furnace will perform at its best with a draft of -0.06 in. W.C.
Slightly higher draft is acceptable and a barometric draft control is not normally required on
this unit but a barometric control must be installed to control excessive draft (more than -
0.08 in. W.C.).

This is from section 6.3 of the manual, notice the last line, draft must be controlled (if excessive, and a 27' chimney will be excessive, mine is). They recommend a BDR which is fine, but my experience, and I think others here would agree, is that they cool the flue too much and can cause some creosote issues. If you are gonna pull the pipe apart to install a damper, then I'd go ahead and put both in, key dampers are cheap.
Did you slide the cardboard in the filter housing to act as a temporary backdraft damper as Dan suggested?
The fan on the Tundra is rated at 1400CFM so it should be adequate for a house the size of yours. If you run both furnace fans they will be fighting each other and also the air from the gas furnace will cool the air steam from the Tundra.

 

[roofyroo]

Let me get this right as I believe I'm missing somethings and some steps...

1. I should install a 6" barometric damper somewhere on the exhaust line from the furnace to the chimney?
2. Buy a manometer to measure the air pressure in the exhaust line. Any suggestions as to something inexpensive? I see they range a lot on price.
3. Install a back draft damper on each hot air outlet.
4. Measure the static air pressure in the hot air outlets.

 

[brenndatomu]

Then you get to the point of adjusting them for proper draft. Dwyer MarkII Model 25 highly recommended for any furnace owner.

+1 on the Dwyer manometer. Can be had for $20 or so on fleabay if you shop a bit or usually $30 will get you one now.

Let me get this right as I believe I'm missing somethings and some steps...

1. I should install a 6" barometric damper somewhere on the exhaust line from the furnace to the chimney?
2. Buy a manometer to measure the air pressure in the exhaust line. Any suggestions as to something inexpensive? I see they range a lot on price.
3. Install a back draft damper on each hot air outlet.
4. Measure the static air pressure in the hot air outlets.

1. Yes, and/or a manual damper
2. See above
3. Yes, and one in the gas furnace too
4. Yes but that is probably not too important if you do the other things first and it is doing the job for you

 

[roofyroo]

Here's what we have right now.

(broken image removed)

So you're saying the existing furnace (square unit in the middle) also needs a back draft damper? This should be installed...where?

I picked up a barometric damper today to install on the exhaust to the chimney flue. No where around here carries back draft dampers for the hot air outlets unless it's ordered in.

 

[laynes69]

A backdraft damper should be installed directly above the central furnace, before your two ducts. This helps to keep the woodfurnace from backfeeding. While the wood furnace is running, can you feel heat exiting the central furnace at the base? If so, you won't get the flow into the main ductwork. Blocking the base of the central furnace would allow pressure to build in your ductwork and flow into your home. If you block it, do not operate the central furnace. Installing the barometric damper and setting it for the highest draft should be safe. Even if it's at .08" you'll be okay. Once the damper closes and the flue temps drop, so will the draft.

 

[roofyroo]

Right okay I understand now when Dan said...

If you are going to use wood heat only you can just tape a piece of cardboard to your filter grill.

I originally thought he meant the filter on my Tundra. That makes more sense as the heat was venting from the base of the main furnace - hence why the house was getting marginally warmer but nothing like I was expecting.

Also I assume if I get one BIG back draft damper for the main furnace then I won't need the 2 8" back draft dampers for the hot air outlets from the wood furnace?

 

[laynes69]

I would still have the two 8" dampers. If you choose not to use the woodfurnace and want to run the central furnace, then close them. Ideally for the main backdraft damper, you just want something that will open when the central furnace blower runs, and close when off.

 

[roofyroo]

So the main backdraft damper in the top of the electric furnace would still be big though - like to fit the whole square inside?

Thanks by the way - card is helping already. Can't get the house above 66 right now though :/

 

[DoubleB]

It appears you could alternatively prevent backflow into the electric furnace by using two backdraft dampers--both in the rectangular trunk above your electric furnace, one damper each between each 8" pipe and the electric furnace. You might consider this if it's easier to get at the main trunk than adding a single backdraft damper top of the electric furnace. A potential problem, though, is that the left 8" duct would only serve registers on the left, and the right 8" duct would only serve registers on the right. And if you have a significantly different amount of registers on either end, you would get imbalanced flow.

Not to mention if you have any runs coming off the trunk right above the furnace, they wouldn't get any warm air from the Tundra.

 

[roofyroo]

I thought about installing 2 but you're right, the airflow would be very imbalanced. Not sure how to install one large backdraft damper yet in the main trunk of the electric furnace, but thats the way to go.

So far the cardboard in the filter is working, although not ideal!

 

[laynes69]

All of our ductwork comes off the woodfurnace and not the central furnace. Because of this, I needed a way to prevent backfeeding. I ended up building a backdraft damper that butterflies open in the middle. That way, I didn't have a large damper swinging open, due to no room. It works well.