Supplimentary Heating for a timberframe with a zero clearance

[ADV]

Hi All.

Looking to get some ideas regarding the following: We're planning on installing a centrally located zero clearance firebox and chimney for supplementary heating of our 3100 sq.ft. timberframe home. Understanding that mass heaters far exceed our budget, and traditional masonry builds are not efficient, we are looking to zero clearance.
Can anyone chime in on their experience with either of the following units: Valcour FP9, pacific energy FP320, RSF Focus 320, or Napoleon high country. We prefer the simple design of the focus, but it seems like the Napoleon and Valcourt have the biggest heating numbers.

My second question regards construction of the stud framing. Because we will be plumbing our HVAC return air along side the chimney pipe up to the wide open 27 foot peak I'm not sure a typical 2x4 stud frame structure that high could support the weight of whatever veneer stone finish we chose.

Any thoughts? Thanks!

 

[Grisu]

Since you are looking for a fireplace with high heat output, I assume you are not just looking for a supplemental heater, correct? When sizing a stove/fireplace the most useful number is usual the firebox size. The bigger the firebox, the more wood goes in, and the more wood you burn, the more heat you get. (As an aside, do you already have several cords of wood split and stacked to get that seasoned for next winter? Any of those options will need wood with a moisture content of less than 20%.) Looking at the size of your home with that big cathedral ceiling I would suggest going as large as possible. 4 cu ft does not sound like overkill. Thus, the PE FP 320 and the RSF Focus would seem too small. I would decide between the FP9 or if you want to go really big the Napoleon NZ6000. Have you looked at the Lennox fireplaces like the Montecito Estate?

 

[ADV]

Well, I guess I'm calling it supplemental heating as I can't predict how effectively this heat source will actually work out given the style of the home and open spaces. Though, it is a SIP home, so heat loss through the walls and roof should be minimal as compared to other construction techniques with thermal bridging etc...
Thanks for adding that a larger firebox is better than a smaller one for all out heating ability. I wasn't sure if a large firebox might burn things too fast and not allow for slow overnight burns.
I do have at least a few years of cut firewood taken from trees felled about 20 months ago. Although non of it is split yet.
I've been doing a bit more research into the FZ6000 (looks almost identical to the Montecito estate) and it seems there is alot of customer dissatisfaction with the Napoleon regarding moving parts and overall quality. Not sure where to look at this point. Its not like I'll get a second kick at the can.

 

[begreen]

You may need a lot less heat than is being advised. SIP structures can be very easy to heat, especially with high-R value glazing. Has a heat loss calculation already been done for the primary heating system? If so, that will provide you with a basis to size the fireplace. Without knowing more it looks like your initial choices are good, especially if you are mostly looking for supplemental heating.

 

[byQ]

It just so happens Temp-Cast is in Ontario. They sell the masonry heater kits. You say mass heaters exceed your budget, mass heaters = masonry heaters? I know masonry heaters are more common in Ontario. It sounds like you have a good house for a masonry heater - well insulated & open style with high ceilings.

Probably the only way you could do a masonry heater and stay on budget would be to buy the kit, assemble it yourself, gather rocks for free from your property/area, and use these rocks to build the shell of the heater.

 

[Grisu]

Well, I guess I'm calling it supplemental heating as I can't predict how effectively this heat source will actually work out given the style of the home and open spaces. Though, it is a SIP home, so heat loss through the walls and roof should be minimal as compared to other construction techniques with thermal bridging etc...

Thanks for pointing out how well insulated your home is. As BG already stated, you may not need such a large unit as I said initially. How do you heat currently and how much fuel do you use?
Also, I would recommend to chose a fireplace that can be connected to an outside air kit. That will improve draft in an air-tight home and you will use cold outside air, not heated room-air for the combustion.
As for supplemental heat: You will probably not have a problem putting an unit in that provides enough heat; the question may be if you can distribute it through the house. Do you have ceiling fans? How well connected is the fireplace room to the rest of the house?

Thanks for adding that a larger firebox is better than a smaller one for all out heating ability. I wasn't sure if a large firebox might burn things too fast and not allow for slow overnight burns.

That is the advantage of newer EPA-approved stoves/fireplaces. You can regulate the air coming into the firebox and thereby reduce the burn rate. With a 3 to 4 cu ft fireplace you should easily have enough coals left in the morning to relight the fire. My 2 cu ft firebox insert still has coals and puts out some heat after a 8 to 10 hours overnight burn on a good load of hardwood.

I do have at least a few years of cut firewood taken from trees felled about 20 months ago. Although non of it is split yet.

Wood barely dries when still in logs. Get that split and stacked as soon as possible in a sunny and windy location. I recommend to cover the stacks on the top (old metal roofing, tarps, etc.) especially if you have softwood in there. For now, I would suggest preparing 4 cords for next winter and after that get going on another 4 cord for the winter after. Goal should be to stack the wood in the winter/early spring for the winter in the following year as many hardwoods need two years to season well.

Are you dead set on a fireplace or would a woodstove also be a possibility? Catalytic stoves (especially Blazeking) have a nice, even heat output and long burn times. You may be hard pressed to find something as good in a fireplace.

And by all means talk also to your local stove shops. The know their units and what would work for you. You can always double check here or you can go to a certified sweep for an unbiased opinion.

 

[ADV]

begreen, I do have a heat loss calculation. It was required for my permits. I haven't looked at it yet as its several pages long. I'll pull it out and let you know what I find. Is there a standard correlation formula between heat loss and heating requirements/fireplace sizing? Assuming the units must be in BTU or similar.

byQ, Thanks for the info, I had heard of Temp-Cast but didn't realize they sold the guts only heater kit. I'm interested but worried that I might need two of them. The main unit we want would sit on the main floor. A connection would obviously have to be made between the main floor unit and the fireplace footing (I had it poured just in case). As piling cinder block etc. or some other economical means to bridge the gap might be an eyesore to the resale world I would probably have to build a basement heater then stack the main floor heater, or install a heater in the basement and zero clearance on the main floor. Either way, I think that would end up costing more money that I'd like to sink at this time.

Grisu, I'm currently in the process of building the home. So far we have a shell and partition walls only. I start wiring tomorrow. I wish I knew what the actual heating requirements were, but I couldn't even guess at it as the house is very open and has high ceiling in almost ever room, not to mention that I've never experienced a SIP home before. Its all new and its got me a little stumped on what to expect. We will be installing fans in almost ever room and the HVAC will be set up to pull the bulk of its return air from high up in the rafters of every room.
Yes I'm itching to start splitting and piling. Hopefully I can make some good time for that this spring. The piles are a 50/50 mix of softwood (hemlock, spruce) and hardwood (maple, cherry, Hawthorn).
The main reason for wanting to go with a fireplace over a stove is that the fireplace is an essential focal point in the design of the house. It needs to prominent and large enough to look in harmony with the rest of the house. There may be enough room to plumb a small stove on the back side of the fireplace near the entrance to the house though...
I've been in talking to a couple of heating stores and at least the two guys I spoke with didn't really have any technical knowledge of how to satisfy my application. The owner of one store had to constantly flip through the Napoleon booklet to get the answers to my questions. The only brand he sells is Napoleon. Unbelievable!

 

[begreen]

BTUs is a common correlation and most likely used in the docs. Sounds like it would be good to visit another dealer or two or three, at least on the phone for starters. Based on the start with the first dealer just imagine how they would handle service problems.

 

[Grisu]

Grisu, I'm currently in the process of building the home. So far we have a shell and partition walls only. I start wiring tomorrow. I wish I knew what the actual heating requirements were, but I couldn't even guess at it as the house is very open and has high ceiling in almost ever room, not to mention that I've never experienced a SIP home before. Its all new and its got me a little stumped on what to expect. We will be installing fans in almost ever room and the HVAC will be set up to pull the bulk of its return air from high up in the rafters of every room.
Yes I'm itching to start splitting and piling. Hopefully I can make some good time for that this spring. The piles are a 50/50 mix of softwood (hemlock, spruce) and hardwood (maple, cherry, Hawthorn).
The main reason for wanting to go with a fireplace over a stove is that the fireplace is an essential focal point in the design of the house. It needs to prominent and large enough to look in harmony with the rest of the house. There may be enough room to plumb a small stove on the back side of the fireplace near the entrance to the house though...
I've been in talking to a couple of heating stores and at least the two guys I spoke with didn't really have any technical knowledge of how to satisfy my application. The owner of one store had to constantly flip through the Napoleon booklet to get the answers to my questions. The only brand he sells is Napoleon. Unbelievable!

I see, when you are just building the home, installing a fireplace makes perfect sense. Some ZC fireplaces can be tied into the HVAC system, which would make heat distribution much easier. Something else to consider. Try to find someone knowledgeable in your area; it will be well worth it. With a proper unit and installation you may be able to almost exclusively rely on wood heat.

For the wood: Split and stack the softwood first (and cover it on top!). That has a good chance to dry until the coming winter although it will not give you the best burn times. Another option (other than looking at a cold fireplace next winter) would be to order 2 to 3 cords split wood right now and stack it at the building site. Won't be fully seasoned next winter but probably burnable. Ask for ash as that dries rather quickly for hardwood and refrain from loads that have lots of oak (as that needs up to 3 years to dry).

 

[Needshave]

We are building a 1200 square ft timber frame with SIP panels. A big selling point to us going this way is the efficiency of the design. I'm a believer. We went to the house in the dead of winter. The general contractor had a space heater. We only had plastic draped over the doors. The house was still warm four hours after he left. Next winter we will see if my heating plan works. I insulated the exterior of the foundation. The wood stove will be heating from the basement.

 

[ADV]

We are building a 1200 square ft timber frame with SIP panels. A big selling point to us going this way is the efficiency of the design. I'm a believer. We went to the house in the dead of winter. The general contractor had a space heater. We only had plastic draped over the doors. The house was still warm four hours after he left. Next winter we will see if my heating plan works. I insulated the exterior of the foundation. The wood stove will be heating from the basement.

Yes, the idea of eliminating thermal bridging and wrapping the whole house in styrofoam was appealing to me as well. What stage are you at? Have you spray foamed the panel seams yet? The cold ended up beating us to the plate so we had to tarp the roof and hold for warmer weather. Still waiting.

 

[Needshave]

They foamed the panels after putting them up. They did have to come back to finish because it was to cold to foam when they put the panels up. We now have rough plumbing and electric inspected. The next thing is drywall.