Location two cool air vents and blower intake?

[builderbob]

Both the Fireplace Xtrordinair and the Napoleon NZ6000 have a blower intake which can draw cool air from vented crawlspace or outside wall. And both units require two other cool air vents as well to cool the shell---and these can also be ducted from vented crawlspace.

So the question is---what if one put the blower in the crawlspace to draw cool air AND one also ducted the two cool air intakes from the crawlspace? Is that trying to get too much cool air from a vented crawlspace? All three intakes would be in close proximity under the fireplace naturally.

Has anyone done this?

You folks can tell I am really getting into this woodburning fireplace technical stuff in our planning for a new home!! And your info, suggestions, and help are just what we need. Thanks all

builderbob

 

[builderbob]

Anyone have any thoughts on this, if not actual experience?

builderbob

 

[begreen]

Bob, never installed one of these, but this is my take on your questions.

As far as I can see with the Napoleon, only the Outside Air Kit (OAK) should be ducted to intake outside air. There is no blower on the OAK. The heater blower definitely should not be bringing in cold outside air in cold climates. You want it to circulate interior room air. It looks ideal for a split level if you can set the blower on a lower level as shown in the manual on page 20. The fireplace also requires ventilation grilles to cool the stove cavity as specified on page 8. But it looks like one can use/circulate interior air like a heatilator. I like this design.

The FP Xtrodinair has left and right options, but has essentially the same setup for the blower. Again, I would not put the blower in the crawlspace, but rather use it to circulate warmth within the house envelope. Separately, the FPX requires exterior cooling and exhaust according to the manual. This seems hugely wasteful. Why dump theheat outdoors? I also don't like having cold air around the firebox. Seems like that might lead to smoky startups. You'll have to ask a dealer for the rationale behind that. The company has a good reputation for their insert, so perhaps I'm missing something here.

 

[bmstove.com]

I'm sorry, I did not understand the part about dumping heat outdoors. The two 7" cooling ducts only cycle cool air from outside and between the walls of the chimney as a cooling mechanism for the chimney itself. It is not connected to the heat exchanger.

It is ok for both the fan and the cooling ducts to be located in the crawl space based on the install manual. I have not heard of any issus of reversed drawing of cooling air. I am sure we have a few of these installs out there ourselves. What I mean is, I have had no complaints or heard of any complaints about smoke possibly being pulled down the outer wall of the chimney and exiting the cooling duct intake in the crawlspace. There is probably too much resistance for that scenario in a ventillated crawl space environment.

 

[begreen]

That's what I was talking about, if one is cooling the chimney, isn't that dumping useful heat outside? I can see this as a plus for folks that want to have a blazing fire in the summer, but I think the days of burning wood just for the ambiance may be going away soon, especially in certain states and urban locations.

 

[builderbob]

Thanks for the thoughts guys.

I am not sure I understand the last point about dumping heat by cooling the chimney. Are you against the whole concept of air cooled chimneys in the first place? The air that cools the chimney is outside air to start with. It is not air you have just heated with the fireplace. I don't see how one "dumps heat" as you state.

Also, you refered earlier in your first post on Fireplace Xtrordinair to their reputation for their *insert*. This unit is not an insert but a zero clearance fireplace. Hence the need also for cool air intake to keep the shell cool---so it can be zero clearance in the first place. Same for the Napoleon NZ6000.

 

[begreen]

Maybe I am misunderstanding the diagrams, but it looks like the Napoleon NZ6000 offers the option of using a solid pack chimney or an air cooled one. In the air cooled case, it appears to be cooled with top and bottom ventilation grilles from the interior of the house. I don't see any mention of using exterior air to cool the chimney on the Napoleon, but perhaps I'm missing something?

 

[bmstove.com]

The top and bottom grills are for warm air circulation in the room. The cooling air for the chimney comes from outside as does dillution air for the chimney in the case of the NZ6000. Chimney cooling air does not get into the heat exchanger portion which would come into the room. Also, the cooling air works by natural convection and not a fan. I am not sure most realize how little air this actually is. The hotter the chimney, the more air moves by convection. But, it does not have any relation as the the amount of usable heat the fireplace is producing. This simply allows you to use a pipe that is about $50 per 36 inch section versus $240 per 36 inch section. That is a real cost advantage to the Xtrordinair.

Last month I performed an on-site consultation with a customer who wanted to build-in a Dutchwest steel insert because it was the cheapest appliance he could find at $1500 retail. For no other reason than his chimney requirements I was able to install an Xtrordinair 36 elite complete and saved him $100 on what he wanted to do. TALK ABOUT VALUE!! Now he has something he can be proud of and an extra hundred bucks in his pocket. Needless to say, I can fish in his pond any time I want to.

 

[begreen]

Thanks for the clarification Jack. The Napoleon manual says air cooled chimney systems are not recommended in colder climates. I was trying to understand how it would be installed up north.

 

[bmstove.com]

That's where that positionable catalyst comes into play. With the directly open flue for loading or ambiance fires, that is enough to keep the smoke moving rapidly.

As for what Napolean says, whether you put packed pipe chimney or double wall, air circulating pipe on theirs it is still gonna be air cooled for the reason I stated previously. Napolean dumps outside air directly into the flue itself for dillution so they can get by the EPA. The massive airflow up the chimney puts them in a different class along with standard fireplaces. The result is whether they want it or not is that they are not just cooling pipe, but they are cooling the flue gasses themselves directly. But, it works. I was first concerned that this may cause draft issues itself but I have not heard of any so far. New product though so we will see as more get into the market. ;-P

 

[builderbob]

Thanks again for all the discussion.

I have reread the install manuals for both the Xtrordinair and the Napoleon, and all your responses. I can see understanding ZC woodburning fireplaces, all the different models, what air is going where, and whether to believe the install manual warnings or the unit brochures on some points, is a fulltime job.

Now, do I understand correctly---do you guys get the same understanding?:
1) Blower is required on Xtrordinair
2) Blower is optional on Napoleon NZ6000
3) On either Xtrordinair or Napoleon NZ 6000, the blower(if used on NZ6000) and blower duct would be circulating air (from either inside house or outside) into the "outer shell" of the fireplace to get heated by going around the outside of the hot firebox, then exiting into the house to warm the house. And the blower simply gives a boost to what happens by natural convection? And this circulation air stream going around the outside of the hot firebox never touches the fire inside the firebox?


Also, I noted in the Napoleon install manual the same "warning" in first few pages to "always operate the fireplace with the doors tighly closed." But later in the same manual it mentions the optional firescreen and open door fires for ambiance. So, same dilema as with Xtrordinair---conflicts between install manual warnings and sales brochures. So that issue is a wash as between the two models. (Perhaps the install manual warnings are boilerplate required by some government safety regs?)

The blower being optional on the Napoleon could give it an advantage in my book. I worry about noise if the blower is installed inside. And if I install blower in crawlspace to lessen the noise, I worry about bringing (letting) too much cold air in the house. Being in the Willamette Valley in western Oregon, we are not in the bitter cold climates, but it can get cold in the winters---this is no Arizona or Florida by any stretch.

I wonder if Napoleon and Xrtordinair have cutaway fireplace models for viewing and studying and trying to understand at their factories.

Thanks again for all your discussion , and anyone else feel free to chime in too, on any of several points.

builderbob

 

[bmstove.com]

All you mention is correct. I want to clarify (or admit factories should clarify) the manual discrepencies. In relation to doors and operation, I fully believe that that intended context by both manufacturers only means that when in normal operation of the fireplace with the doors close, please make sure the doors are tightly closed and not just loosly closed. A door that is cracked will raise firebox temperatures dramatically which can cause an unsafe situation in anyone's appliance. A fully open door sucks in so much air that it cools things down in the appliance. I at least don't think those statements were meant to conflict but you know these companies pay special people (technical writers) to write the manuals so we can wonder what the heck they meant by that.

The fan is included with the Xtrordinair. The motor itself is extremely quiet by design. I don't think it is ever mentioned, but there is an automatic damper in the blower box of the Xtrordinair. It only opens when the fan is on. In my showroom my fan is sitting on top of the fireplace beside the 44 elite about head high. On high it is not a big deal and I can turn it down to not even hear it even though it is not mounted and just sitting there so I can turn it and show it to customers. If you want to really heat your place, you're gonna want a fan on either model. The noise is really not an issue since both will turn down with their rheostat features or even off if you like.

I've yet to see a cutaway on the NZ6000 but I do know that the wood fireplaces brochure has a nice graphic showing the xtrordinairs internal organs and how they work. I recommend downloading that at www.fireplacex.com.

 

[builderbob]

You guys are the best! Thanks for that firsthand info on the Xtrordinair fan sound level.

I did take a look at the brochure and I see it has the damper in the fan blower box. So even if I would decide to mount the blower in the crawlspace, then when not in use, that duct and fan box with damper shut would close off much migration of cold air into, or warm house air out.

I wish Napoleon has such a good cutaway view of its inards.

So, in my (now hopefully) less confused mind, I now see Fireplace Xtrordinair with advantages over Napoleon NZ6000 as:
1) cost----can use AC chimney (and fan blower comes with unit, not as extra cost option?)
2) install cavity does not require metal studs and cement board as does Napoleon---more cost savings for simpler install
3)Xtrordinair gives actual data for burn cleaness and efficiency (Napoleon does not)
4)install cavity does not require vents open to inside of house to keep cavity cool enough for safety as does Napoleon---meaning cavity itself can be fully insulated (which I think is requried for Xtrordinair install anyway)
5)Xrtordinair model has longer field tested history than Napoleon.
6)Xtrodinair gives 2+ years parts and labor warranty---Napoleon gives lifetime parts but only 1 year labor.

I see them both as goodlooking units, and both have large enough doors for ambiance viewing (ie, bigger than 14+" x 26+"
Both seem to have users who have stated satisfaction on this forum.

Napoleon has advantages:
1)allows gravity ducting for heating adjacent or upstairs room areas
2)does not require catalytic converter or associated maintenance or replacement costs
3)uses AC or solid pack chimney. Solid pack chimney *might* promote better draw and less puffing into room (if burning with doors open----irrelevant if burning with doors closed). On an install like we plan with chimney inside heated envelope of house, differences perhaps not so noticable anyway.

Thanks again for input, and if anyone sees some advanatges or disadvantages for one unit or the other I haven't thought of---please post!!

builderbob

 

[begreen]

BB, what is adjacent to the fireplace location? Is there any chance locating the blower so that is pulling air from a nearby room, under a staircase or perhaps a hallway?

Pulling air from the crawlspace may put a musty odor into the house. And the air will be n degrees cooler which will reduce the output air temp into the room.

 

[builderbob]

The fireplace module will face the living room. On the backside will be the dining and then the kitchen. One end of the fireplace will be about 8 to 9 feet from a wall of the central hallway. The other end of the fireplace will be an outside wall.

I can see perhaps a few disadvantages of a crawlspace mount for the blower. I did have one fireshop person mention an advantage of a crawlspace mount would be it could circulate cool air in the summer. But then again, that cool air could still be musty smelling.

Also, Xrtrordinair mentions its feature of "positive pressurizing" of a home by drawing outside air.

Thanks for the thoughts.


builderbob

 

[builderbob]

Another thing I was thinking about, speaking of outside air and the blower.

Houses are being built so tight now, that the construction trade is starting to recommend as part of the heatpump/furnace systems that people have "heat exchangers" installed which bring in fresh air into the home. They use the same terms of "pressurizing" the home. And they talk of getting the old stale air out and replaced with new fresh air. The old leaky houses of a few decades ago used to do this air exchange adequately on their own, just by leaky windows, doors, ceilings etc. Now the air exchange does not occur often enough, that they recommend the heat exchangers to do it.

I was thinking, the Xrtrordinair could be the "heat exchager" and do the replacement of the stale air with fresh air.

I can't remember all the problems they said were caused by inadequate exchange of stale air with fresh in the new tight homes, but they had a list.

Comments on this subject?

builderbob

 

[begreen]

If the house is air tight and this is a concern, use an air to air heat exhanger. It will be much more efficient and filtered. (Note, the stove already has an OAK.)