ZC Woodstove Chimney/ Hot air ducting/movement questions...yes a noob...

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
  • Super Cedar firestarters 30% discount Use code Hearth2024 Click here

vws4life

New Member
May 4, 2020
2
Vermont
HI All , New to the Forums, have had many questions answered one the years without having to post. I've (re-)installed a few freestanding wood stoves, and a couple of inserts in masonry but this is my first dealing with ZC. Have a few questions that I can't seem to resolve with basic research.

Heres the project recap so far.

House was built in '88, came with a Heatilator (HF36) ZC stove, corner installation. The house was designed/framed around the vertical chase right through the roof. The heatilator is long past its useful life, although it sounds as though it wasn't of much use when it was new up here in VT. We purchased a Nordica Equinox ZC Woodturning stove a couple years ago, and I'm now getting around to remodeling that floor. The install seems pretty straightforward, its the removal that is going to be the bi**ch. Seems every section of chimney is clamped, supported and strapped to the chase; I was hoping for a lightweight install than would just collapse when I puled out the stove. The chase is huge, it is already fire rocked, and there is 2" clearance on the 10" pipe, so will theoretically have 3" clearances if I keep the chimney centered.

Question #1 As far as the chimney install, the owners manual has listed tested class A models (CF Sentinal/Ultratemp/Superpro ALT or SPR/sSupervent JSC or JM/Duraplus HTC or Duratech) My neighbor was kind enough to give me some lengths of selkirk/metalbestos SS.

#1 Selkirk states that their Ultra Temp is compatible with the older SS/SSII, is there any reason that I should not do so?
#2 Assuming I do so, should I locate the older lengths farther away from the unit, so it is theoretically exposed to cooler temps?

The nordica is setup with air circulation; 2 lower intake ports, and 2 side plus 2 top vents for warm air, they recommend using the top 2 for gravity movement and the sides to be used with a ventilation fan 100-500 cfm depending on run length. The plan is to locate one of the ambient air intakes will be located below the stove, one hot vent below (with fan?) the stove, and a second vent ducted through the wall into the adjacent room with (approx 6' length) insulated duct. I was hoping to use an inline fan to move the air, but was unsure of the type and CFM (and noise associated with) to go with since it is a rather short run, down 4 feet and horizontally 2 feet. I imagine any inline fan is going to way quieter than the current Heatilator fans.

#3 Does anyone have any recommendations on the location and brand of fan to use? The heated air duct register would be physically only 3-4 feet from the stove and manuals say to keep the fans minimum 10 feet from the heat source...
#4 And also, this thread was giving me concern as well. Is the factory ducting of hot air against code as it suggests in the thread?


#5 If I can safely duct, am I required to put the fan on a thermostat or can I use a timer ( i was thinking of a bathroom fan timer)?
#6 As far as the intake air ducts, any reason one of them can not be located in the room below? will this case any negative airflow issue?

I'm sure the way I plan to duct may not be the most efficient method, but I'm giving up some for aesthetics. And it seems you guys like photos, so a bunch are attached, let me know if more are needed.

Thanks in advance for this great resource!!

Chris

[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...[Hearth.com] ZC Woodstove Chimney/ Hot air ducting/movement  questions...yes a noob...

Old Heatilator
Chase/chimney
New stove
Venting diagram
 
While that is a kind thought from the neighbor I would not mix the chimney pipe, and I would never put in used chimney in this situation. The chimney is infrastructure. You do not want to have second thoughts about or deal with a replacement in 5 yrs for part of the chimney inside the chase. That would not be fun. Put in all new.

The image for the heating duct is small, but the first one appears to show the blower on the intake side. This makes more sense because then it is pulling in cooler room air and doesn't have the risks associated with high-temp output air. Pulling air for this from the room below will reduce pressure in that area. This could cause problems if there are any combustion appliances there. (hw heater, furnace, stove, fireplace, etc.)
 
While that is a kind thought from the neighbor I would not mix the chimney pipe, and I would never put in used chimney in this situation. The chimney is infrastructure. You do not want to have second thoughts about or deal with a replacement in 5 yrs for part of the chimney inside the chase. That would not be fun. Put in all new.

The image for the heating duct is small, but the first one appears to show the blower on the intake side. This makes more sense because then it is pulling in cooler room air and doesn't have the risks associated with high-temp output air. Pulling air for this from the room below will reduce pressure in that area. This could cause problems if there are any combustion appliances there. (hw heater, furnace, stove, fireplace, etc.)


begreen thank you for the reply. since posting, I have resolved a few things, but raised more questions.

We are in agreement that I'll just get new metalbestos Ultra temp, having issues years down the road to save a couple of hundred was a bad plan.

As far was the ducting, there are actually lower ambient air intakes on both sides of the stove and plan on using only the top outputs for the hot air. I am now going to elevate the stove about 12" off the floor, and build in a wood storage bin and have the ambient intakes on either side of the wood storage on the floor.

Since my warm air run is so short, is there any issues with putting a pair of variable speed fans (100 cfm each) on the ambient intake?
My assumption is that having the fans on the hot air exit duct closer than 10' from source may overheat/fry them. And all the other circulating fireboxes i've had over the years pushed air rather than pulled it..as its really only traveling 3 feet on the top exit and 4 feet on the side, this seems like a fair idea.

cheers
 
Last edited: