Kozy Heat z42 CD for our new home?

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RRMM

New Member
May 9, 2014
28
Ashe County, NC
We're building a new home in Ashe County, NC, not far from Boone, and want to confirm that the Kozy Heat will be a good choice for us. After spending hours on this fine website exploring and researching, I feel like we're headed in the right direction at least.
Our purpose for wanting an EPA certified ZC wood burning fireplace insert: both my husband and I grew up in CT with wood-burning masonry fireplaces (plus, my dad had a wood burning stove next to the oil furnace that rerouted all the water through it, with the furnace only coming on when needed... currently, we are not prepared to take on that level of wood heating/wood requirement!). Our current home has a ventless gas FP that we used about 8 times when we first moved here in 2000, and not since because we dislike it. We want 1) a FP that will provide the ambience of a wood burning fire 2) to be more efficient in terms of amount of wood used and environmental impact 3) a FP that will actually put heat into the room instead of draw it out. The builder was going to put in a builder grade Bungalow ZC unit, but after research, we discovered we really didn't want that. At first, I looked at FP inserts but after a bit realized they were for existing masonry fireplaces. Unfortunately, we are now at the point where our builder needs to know FP specs by early next week.
Our concerns: 1)That it will make the room too hot. After reading some of the many posts here of 80* rooms with windows open, I worry about being able to sit in the fireplace area and socialize/watch TV/etc. 2) That guests who use the house could mess something up.
The specifics of the house:
Floor plan posted below. The main floor where there fireplace will be located is 1300 sq ft, with the LR, DR, Kitchen in an open floor plan, the kitchen being at a right angle to the dining room area. The bedroom is down a hallway which is close to the location of the fireplace. An open (to one side, the side away from the FP open to the kitchen) staircase leads to the 800 sq ft upstairs, to a hallway with one small bedroom to the left and a master suite to the right. The stairwell is 17' high. These are not located above the LR/DR area, but over the kitchen/BR. The ceiling in the LR/DR is a shed ceiling starting at 9' and rising to about 13 feet. There will be ceiling fan in the middle of the room. The fireplace is located on an exterior south facing wall, at a point where the ceiling is about 11 feet high.
Location: on a windy hillside with great views. The lot is treeless (nothing to impede the 270* views) but after viewing this site I now interpret as no source for free wood :). It's at 3100 ft elevation. In the winter it can get quite cold for NC standards... in the teens with below zero wind chills. It can just as soon be 40-50* or more in January.
Heating/Cooling considerations:
Electric heat. Only options were propane or electric. As you can see from the floor plan, there are lots of windows. These are all standard height, high quality, insulated windows which are rated for high winds. 2x6 Construction which will have blown-in insulation. I have no idea what the heat demand is, but with the square footage of 2100 at and above the FP level, and another heated 800 sf in the basement, our load is requiring one heat pump. We are not looking at the FP insert as the primary source of heat, though I guess it would be wonderful if it can cut the heating costs without blasting us out of the room.
Wood source: None yet! From Grisu's many comments, I now realize we are waaayyy behind in procuring wood. Since we will only be there on weekends and holidays, perhaps the many unbuilt, timbered lots in the development, which might provide a source of fallen aged wood. Plus the site really is very sunny and breezy for drying wood.
Many thanks to the moderators and contributors to this site. It has been an enormous help already, and I look forward to hearing comments.
 

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Ah Boone. I almost moved there back in the 70's. Love that area.

Welcome to hearth.com. I would go electric for the primary heat. For sure put in a very high efficiency 2 stage heat pump system (if central forced air is prefered) like Trane, American Standard or Lennox make. Or consider a super efficient mini-split system from Mitusbishi, Daikin, Fujitsu.

For the fireplace size, it will depend on how well insulated the house is. There are methods in new construction to make the heating needs very low. It all depends on how much is spent initially to make a tight outer envelope for the house. You need to have heat loss calculations done on the house soon so that the heating system requirements are determined. The Kozy is an excellent unit with a good reputation. But if the heat loss calculations show that you need a smaller unit, no problem. The BIS Tradition or perhaps a Pacific Energy FP30 would work as smaller units. And remember, you control the fire. If the weather is mild and you don't want to overheat the place, just burn a small fire of 4-5 splits and let the fire go out.

And yes, find someone in the area with a good reputation for seasoned wood sales and buy a few cords right away to stack on the property. Try to avoid oak and hickory for this coming season's firewood. (But no problem to buy ahead for 2015-2016 if you can). Ash is good if available.
 
Ah Boone. I almost moved there back in the 70's. Love that area.

Welcome to hearth.com. I would go electric for the primary heat. For sure put in a very high efficiency 2 stage heat pump system (if central forced air is prefered) like Trane, American Standard or Lennox make. Or consider a super efficient mini-split system from Mitusbishi, Daikin, Fujitsu.

For the fireplace size, it will depend on how well insulated the house is. There are methods in new construction to make the heating needs very low. It all depends on how much is spent initially to make a tight outer envelope for the house. You need to have heat loss calculations done on the house soon so that the heating system requirements are determined. The Kozy is an excellent unit with a good reputation. But if the heat loss calculations show that you need a smaller unit, no problem. The BIS Tradition or perhaps a Pacific Energy FP30 would work as smaller units. And remember, you control the fire. If the weather is mild and you don't want to overheat the place, just burn a small fire of 4-5 splits and let the fire go out.

And yes, find someone in the area with a good reputation for seasoned wood sales and buy a few cords right away to stack on the property. Try to avoid oak and hickory for this coming season's firewood. (But no problem to buy ahead for 2015-2016 if you can). Ash is good if available.
Thank you for this advice! I will need to ask if a heat loss calculation was done. Here is what our contract says as for insulation: "Provide insulation that meets or exceeds local building codes. Insulation shall be provided in bedroom and bathroom walls also. Exterior walls = R-23, Floor= R-19, Ceiling=R-38. Upgraded insulation in the wall (optima blow-in)." Windows: Hurd with insulating double pane low E, argon filled. Other entrance doors shall be steel 6 panel doors.
The construction is 2x6, with log siding and sheet rock. Roof is sheathed with 5/8" OSB, titanium roofing paper, and metal roofing. HVAC is an electric heat pump system with air conditioning. Everything is built to withstand high wind, as we are in a "high wind area." I know that still doesn't answer the heat loss calculation question, but does it say anything to you? Are there any ZC fireplaces that aren't actually stoves, but that provide some heat without causing heat loss?
I feel rather stupid that it has gotten this late in the process and I still don't know what I'm doing. I would, however, want to be on the side of having too much heat from less wood than losing heat with a lot of wood! Oddly, I don't remember the two story masonry fireplace in my childhood - college home feeling drafty or cold away from the hearth. My dad did install a blower in it, so I guess it must not have had any efficiency before that. All I remember is the wonder of having a fire, adding wood to it, rearranging the logs, etc. Somewhere here I read that the emotional pull of a FP is one of the main reasons people decide to go that route.
I am so thankful for this site, but it seems the more I read, the more confused I get!
 
The insulation sounds average for new construction. What is the make/model and specification (heating capacity) for the heat pump?

It looks like the Kozy will do the job ok. It will be up to you to burn smaller fires during milder weather. In the dead of winter you probably will be able to burn a steady fire all day. One advantage here would be to duct some of the heat to the room to the right of the bathroom. That would help even out the warmth.

However, if you mostly want the fireplace for ambiance then go a bit smaller with the 2 cu ft BIS Tradition CE (same as Lennox Montecito) or an RSF Topaz. A less expensive and more flexible alternative would be to install a nice looking freestanding stove on a beautiful hearth. For ideas there are some shots of each in the gallery section. https://www.hearth.com/gall/main.php

PS: How frequent and long are power outages in this neighborhood?
 
Using the heat loss calculator I found on hearth.com (clearly I didn't research as much as I should have... mainly read forums), I have calculated the heat loss for just the main living area to be just under 40,000. This does not take into account the hallway, the open stairwell, and the 800 sf upstairs, which can be changed by opening or closing the doors at the ends of the hallway. The hallway cannot be closed off. Our self-created problem is the main seating area of the house requires the end of the sofa to be about 5' away from the FP. I guess I have to figure out how much we'll be able to control the heat thrown off by a unit. The Kozy Heat z42 seems like one of our best options given the dealers/installers who are local to us, but some of the posts here about even large rooms being upwards of 80* scares me. The brochure says it puts out 30,500 BTU/hr EPA test wood and 75,000 BTU/hr seasoned cord. I've learned here that the type of wood can affect that, as well as the fact that we have an exterior chimney. The ceiling does go up to 13' on one side of the room, and heat will surely travel up the stairwell, but to get there, it has to go across the seating area. Would I be correct in guessing that if you open a window across the room from the FP, the heat will be pulled that way? What if you open a window next to the FP? Will that prevent some heat from moving across the rest of the room?
 
The insulation sounds average for new construction. What is the make/model and specification (heating capacity) for the heat pump?

It looks like the Kozy will do the job ok. It will be up to you to burn smaller fires during milder weather. In the dead of winter you probably will be able to burn a steady fire all day. One advantage here would be to duct some of the heat to the room to the right of the bathroom. That would help even out the warmth.

However, if you mostly want the fireplace for ambiance then go a bit smaller with the 2 cu ft BIS Tradition CE (same as Lennox Montecito) or an RSF Topaz. A less expensive and more flexible alternative would be to install a nice looking freestanding stove on a beautiful hearth. For ideas there are some shots of each in the gallery section. https://www.hearth.com/gall/main.php

PS: How frequent and long are power outages in this neighborhood?
Oops! Was posting the same time as you. I will ask a full-time resident how often the power goes out. I'm not sure what capacity the heat pump will have; our contract does not address that. I know each floor will have its own zone for heating. The walk-out basement level I suppose doesn't matter in this discussion because it's below the fireplace room. The ducting is a good idea. In reading some of the other posts, I realize I can bring one duct into that bedroom and perhaps one upstairs to the main area of the second floor. It appears that the Kozy Heat can't be ducted downstairs very easily, which would have been a nice option. Since we are still in the rough stage, I guess all of this duct work could still be done. Plumbing and electric are in, and the electrician accounted for the fan since we had already gotten to the point of wanting one of these inserts. Nothing that can't be moved around if need be, though we'd like not to incur extra expense. Do you know if the ducts are controllable, i.e., can you shut them off if you want?
 
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Be sure the plumber knows this in advance and sets up the lines with proper slope for drainage. You are going to need extra heating power to bring that house up to temperature in the winter. It can take hours to move a house interior from 50F to 70F when it's below 20 outside. I would get the Z42 and stock up on dry wood, stored in a wood shed.
 
Hello RRMM and welcome to the forum!

Our concerns: 1)That it will make the room too hot. After reading some of the many posts here of 80* rooms with windows open, I worry about being able to sit in the fireplace area and socialize/watch TV/etc.

No guarantee certainly but I think you misread some of those posts. People don't need to get their stove room to 80 F but boast a bit about the heat their stove/insert puts out. If you need less, just load less wood and fill the fireplace less often. You only have a problem when you need your living room to get that hot in order to keep the other parts of the house heated. However, you have a pretty open floorplan and the heat should travel well to most parts of the house. You may also be able to use the HVAC system to distribute the warm air. I think the KozyHeat would be a good size for your house.
2) That guests who use the house could mess something up.

What kind of guests? Are you planning on renting out the house? That could potentially be a problem because modern stoves/fireplaces have a learning curve. At a minimum, you would need to leave clear instructions, a stash of dry wood, and a thermometer to monitor temps. Even then I would not feel overly comfortable letting newbies run the fireplace. See if it can be installed with some extra room regarding the clearances to the studs etc.
Location: on a windy hillside with great views. The lot is treeless (nothing to impede the 270* views)

I wanted to suggest to plant shrubs at side of the house which is facing the prevailing wind direction but since that would impede the view just make sure your house is as airtight as possible to avoid drafts. I would suggest installing the fireplace with an outside air kit then.
It's at 3100 ft elevation.

That's pretty high up and may require some more ft added to the chimney than what is usually recommended for the KozyHeat. Ask the installer about it.
The ceiling does go up to 13' on one side of the room, and heat will surely travel up the stairwell, but to get there, it has to go across the seating area.

Warm air rises. If you keep the blower on low you may mostly notice the radiant heat from the fireplace more than the heated air from the convection.

About the KozyHeat Z42: I would suggest the single door Z42 version over the Z42 CD. You will run the unit with the doors closed and then the double door will impede your view of the fire. Plus, some more gaskets to worry about and the handle on one side is fixed while the one on the other side may end up at a different angle than the fixed one. May look a bit awkward, IMHO.
 
Hello RRMM and welcome to the forum!



No guarantee certainly but I think you misread some of those posts. People don't need to get their stove room to 80 F but boast a bit about the heat their stove/insert puts out. If you need less, just load less wood and fill the fireplace less often. You only have a problem when you need your living room to get that hot in order to keep the other parts of the house heated. However, you have a pretty open floorplan and the heat should travel well to most parts of the house. You may also be able to use the HVAC system to distribute the warm air. I think the KozyHeat would be a good size for your house.


What kind of guests? Are you planning on renting out the house? That could potentially be a problem because modern stoves/fireplaces have a learning curve. At a minimum, you would need to leave clear instructions, a stash of dry wood, and a thermometer to monitor temps. Even then I would not feel overly comfortable letting newbies run the fireplace. See if it can be installed with some extra room regarding the clearances to the studs etc.


I wanted to suggest to plant shrubs at side of the house which is facing the prevailing wind direction but since that would impede the view just make sure your house is as airtight as possible to avoid drafts. I would suggest installing the fireplace with an outside air kit then.


That's pretty high up and may require some more ft added to the chimney than what is usually recommended for the KozyHeat. Ask the installer about it.


Warm air rises. If you keep the blower on low you may mostly notice the radiant heat from the fireplace more than the heated air from the convection.

About the KozyHeat Z42: I would suggest the single door Z42 version over the Z42 CD. You will run the unit with the doors closed and then the double door will impede your view of the fire. Plus, some more gaskets to worry about and the handle on one side is fixed while the one on the other side may end up at a different angle than the fixed one. May look a bit awkward, IMHO.
Thank you for your suggestions, Grisu. I especially find your first comment hits the mark. I WAS assuming the fireplace just reaches those temperatures no matter what. I know you've remarked before that WE control the fire, but somehow, it didn't register that perhaps the people with rooms that hot were using their insert to actually heat their whole house. As for guests, that's what I suspected after more research. I know when I rent a ski place in your wonderful VT, we like to use the FP, but I always think to myself "good thing for these folks we know how..." And clearly these ZC efficient inserts are more complicated. I will speak to the installer about the added height to the chimney. Even the salesperson seems very knowledgable so far, so I feel comfortable with who we're using. Your comments are certainly very helpful and comforting. Hopefully I'll be able to sleep again after this decision is made, lol.
 
One other thing to keep in mind.... Once you burn wood you tend to enjoy the warmer room temps. My stove room runs around 76F on a daily basis during the winter.


For me its odd. I like it cold usually. Summer we keep the house at 68F. And in the bedroom I like it cold for sleeping. But I actually love my stove room. You just get used to having it warm. It gets down to 74F and im cold now in the winter.
 
Since this thread addresses burn time, too, and begreen and Grisu are both reading (thanks!), what exactly IS burn time? Is it how long there are actual flames coming from the wood you put it, or is it just how long the unit gives off heat once you've added your last logs? How long does the wood generally generate flames vs. when they turn to hot, glowing embers? From what I'm reading, burning a not hot enough fire will cause the soot. Not having a hot enough fire is caused by wood still moist, and... anything else? Too small a fire in the firebox? Thanks for all your help. We are having the Kozy Heat salesperson come to the home on Tuesday to evaluate the feasibility of the unit, see how it can be ducted, etc. You all have been a tremendous help.

To keep your questions separate from the other thread, I am answering here. There is no defined standard for burn time. Generally accepted here is the time from loading the stove until you still have enough hot coals left for an easy restart. Depending on the size of your stove (fireplace) you will see fire for maybe 2 to 3 hours and some flames for about another one to two hours. After that it will be down to glowing embers but the stove will still give quite a bit of heat. Burn times for secondary burn stoves are usually 8 to 12 hours, depending on wood species used, size of splits, dryness of wood, draft, air control setting etc. Catalytic stoves can extend those times.

You will also not get a hot enough fire when the draft is insufficient, either by closing the air down too early or too much or having a inappropriate install (short flue, wrong-size flue, airtight home etc.).
 
Between your comments and the ones on other thread I jumped into we felt quite comfortable focusing on the Kozy Heat z24 option that was one of a couple of units available from relatively local installers. The salesman came this morning (I was not able to be there) and determined that the stove will work well for our application. He will be able to do ducting with blowers to common areas in the basement and the second floor from the main floor LR (stove room). The electrician and the framers were there, and they are all on board. Armed with the information from this website and the answers to all my questions, we are quite excited to jump into the world of EPA ZC High Efficiency fireplace use! Our builder, an solid, reliable, old-school guy, is leery as he has not had any experience with these units. First time for everything! Once the unit is ordered, we'll have wood delivered for three years ahead... which will be a wild guess as to how much, since it's a vacation home.... and start collecting dried fallen timber, pallets, and the like for this winter. Any precautions on that other than the obvious treated/rotted/lichen-covered wood? Have read about the bio-brick options from Tractor Supply, etc. and that will serve well the first year too, esp. since we aren't there full time. Though I've started and tended many fires in my time I anticipate the learning curve involved with this, for which I will be avidly reading this website. I'm not anticipating problems; I'm armed with research and a good reference website :)! I want to thank all of you for your knowledge and insight, patience, and time. I'll let you know how it turns out.
 
Great, I'm glad it worked out for you. Take some pictures as the project progresses.
 
Temps hovering nicely at 225 - 250 with proper air intake/outflow control and just the right combo of dry and wet fuel; smoke wafting out of the unit. Just perfect.... oh wait, that's the smoker. Can't wait for that brisket tonight!
 

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Those aren't the requested pictures, but I couldn't resist. I'll have the first photos of the framing taken this weekend. Thanks again for all your help, everyone!
 
Our house is FINALLY nearing completion, hope to get the CO by the end of the month. Here's an short picture history of the Kozy Heat z24 so far. Even though I know it's zero clearance and made to be installed in wood, it still seems very odd to me. It's a bit scary, but I guess we'll get used to it. The mantle is still being made. I'll let you all know how the first burn goes and provide more pictures.
Kozy Heat z42 CD for our new home?Kozy Heat z42 CD for our new home?Kozy Heat z42 CD for our new home?
 
Getting a lot closer. Were you able to stock up on seasoned wood last May?
 
Unfortunately not. Our builder asked us not to because they needed access to much of the lot. It's on a pretty big slope, so storing the wood anywhere that wouldn't be in the way would have made it very inconvenient. Our neighbor kindly let us store a moderate pile of wood scraps from the building process (unfinished pine and oak flooring scraps) under their deck. So at least we've got a bit of wood for the first few burns. Also, the builder mentioned we could raid some of their other dumpsters through the season, since we didn't get to save nearly as much as they threw out… a new form of dumpster diving, I guess. Hopefully we can find seasoned wood. We'll only be there on weekends for now, so our wood requirements aren't that high yet. We were expecting to finish much sooner than this, so looking on the bright side it's rather exciting that the weather will be appropriate to begin using the fireplace immediately.
 
We have the Kozy Z42CD and us it for most of our heating needs. We heat 1 1/2 stories with it approximately 2300 sqft. I installed the switch on the wall a distance away from the z42 so i wouldnt have to open up the bottom grate to get to the blower settings. Last year we went through a little over 4 cords. Your install and hearth turned out great.
 
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Here it is: the first burn! Working great so far. We still have to figure some things out, but so far, so good. Haven't burned it hot enough to ignite the secondaries, but it's still heating the main floor and upstairs nicely. Thanks for all the help provided through this website! Hope you all had a good Christmas. Best wishes for a marvelous 2015!

Kozy Heat z42 CD for our new home?
 
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Thanks for the update. It finished out nicely.

I suspect you are already getting secondary burning, but maybe giving the fire too much air? When burning after a reload, turn down the air once the fire is burning well until the flames start to get lazy. Let the fire regain steam, then turn it down again until the flames get lazy. That should encourage strong secondary burning.
 
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Thanks for the update. It finished out nicely.

I suspect you are already getting secondary burning, but maybe giving the fire too much air? When burning after a reload, turn down the air once the fire is burning well until the flames start to get lazy. Let the fire regain steam, then turn it down again until the flames get lazy. That should encourage strong secondary burning.
Thanks, begreen! Followed your advice and the result is below. Really neat! The one window is a little sooty, but it ended up burning clean, as did all the bricks… not a trace of soot anywhere. There wasn't much to begin with, but I guess it's all part of the learning curve.
Kozy Heat z42 CD for our new home?
 
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That's the idea. Secondary combustion increases once the fire is hot and the primary air is reduced. Looks like a big full blaze. You may be opening windows soon. :)
 
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