Effective Heating during Power Outage Options

[overlandsea]

Hello, I'm still trying to narrow down my options for replacing a ZC fireplace. Wondering if those with more experience would chime in with their opinion the effectiveness of these heating options.

1) Current ZC fireplace (superior). From what I've learned so far, this likely results in little or no actual heating of the room.
2) EPA rated ZC with louvers (blower wouldn't work during power outage) Right now I'm leaning toward Supreme Astra 24, which can be installed with louvers or clean face.
3) EPA rated ZC with a clean face kit and gravity kit
4) EPA rated ZC with louvers and gravity kit
5) Wood stove (something like a Banff 1400)

Is there a significant advantage for any of the EPA options when heating without power? It seems like the gravity kit might be an advantage then? I know it won't be as effective as a wood stove, but to what degree? Thanks!

 

[Zack R]

A freestanding wood stove will be your best option for heating during a power outage.

 

[overlandsea]

A freestanding wood stove will be your best option for heating during a power outage.

Any estimation to what extent? Like is there a general rule that would say something like "a wood stove is twice as effective in heating during a power outage for similar BTU rating"? Or any other estimate of how you might quantify it?

 

[kennyp2339]

similar BTU rating

That right there is what's jamming you up.. you cannot make a educated decision based solely on a btu rating, most ratings are falx.
Put it to you this way.. there are many freestanding woodstoves that don't even come with blowers that rely upon radiant heat to heat 1500-2000sq ft. (wood stock soap stone is the first that comes to my mind)
Then there are the natural convective stoves such as (not made anymore) Kuma sequoia and then the other big radiators like the Englander nc30, pe t6, BK king and princess just to name a few
I just went through a 2 day power outage 2 wks ago and ran the princess like normal (without blower) house stay decently warm as temps dipped into the lower 20's at night, the house prob would have been warmer if I had a more open floor plan to establish a natural convective loop.

 

[Zack R]

The key thing with a freestanding stove is that it creates a convective loop, so it can heat an area well without a blower. I'm not sure how to quantify how much more effective it would be than an insert or fireplace but I do know a properly sized stove can keep at least part of the house very comfortable during a power outage.

@begreen is located in the Puget Sound and can offer some ideas on what stove might be a good match for your climate.

As a side note I have two freestanding stoves, a 2500sqft house with a ton of windows and haven't used the furnace in a few days, the house is comfortable at 70F. The low's have been around 15F, highs around 35F.

 

[begreen]

Any estimation to what extent? Like is there a general rule that would say something like "a wood stove is twice as effective in heating during a power outage for similar BTU rating"? Or any other estimate of how you might quantify it?

That would depend on the stove choice, location and the house design and floorplan. The stove is an area heater. Some are more radiant and others are more convective in design. The same stove in a different house can heat quite differently.

Describe the house, floorplan, stove location and ceiling height for a better answer.

 

[overlandsea]

Here's a sketch of the floor plan. Kitchen, dining, and living are all open. The fireplace or stove would go where the star is. Ceiling is 10 foot cathedral in the open area and 8 foot in the bedrooms/bathrooms. Extremely well sealed with good insulation.

 

[jetsam]

A freestanding woodstove is many times better at getting BTUs into the room than a ZC/flush insert without a blower. Maybe 10x, at a very rough guess.

That's a pretty good layout for wood heating.

The best no-power option is a freestander, hands down. If you don't want to do all that construction, a semi-flush insert is the next stop (some, like the BK Princess insert, even have enough stovetop that you can put a thermovoltaic fan on top). After that, the worst option is zc or flush inserts.

You may or may not be allowed to put an insert in your old ZC; I'd start by figuring that out.

A generator (or a couple deep cycle batteries and a solar charger) is probably cheaper than building a hearth, and would let you run a ZC fan during outages.

If you don't mind the expense and lost floor area of getting the freestander installed, that will get the most BTUs into your house whether or not the power is on.

 

[begreen]

Here's a sketch of the floor plan. Kitchen, dining, and living are all open. The fireplace or stove would go where the star is. Ceiling is 10 foot cathedral in the open area and 8 foot in the bedrooms/bathrooms. Extremely well sealed with good insulation.
View attachment 253619

That's pretty good for a location, should be easy to heat if you don't mind the bedrooms being cooler. The master bath will get the short end of the stick unless it has a transom vent into the Living Room. You would do fine with a stove in the 2-3 cu ft range or in between. Is that where the Superior currently is located?

 

[kennyp2339]

Is it possible to run a duct under the main floor to an outside wall for an outside air connection? A medium sized tight house might be tough to keep while using inside air for combustion since bathroom fans, dryers, and range hood all might be fighting for the same air at one point in time.

 

[begreen]

Is it possible to run a duct under the main floor to an outside wall for an outside air connection? A medium sized tight house might be tough to keep while using inside air for combustion since bathroom fans, dryers, and range hood all might be fighting for the same air at one point in time.

Yes it is. If the run is long, go up a size in the duct.

 

[overlandsea]

Yes, the star is also the current location of the superior. That currently has an outside air vent that goes up to the roof. I've seen some manuals want outside air further away from the chimney. Below is a finished basement, so out the roof is probably the only choice (or no outside air and cracking a window).

 

[overlandsea]

Follow up question. Seems like the consensus is heavily towards wood stoves...for a power outage scenario, would you rather have a small woodstove (Morso, Jotul F3 or Hearthstone Craftsbury) than a much larger EPA ZC like Flame Monaco/Osburn Stratford? Asking more about effectiveness of heating...I know burn times will be short. The relevance of the question is that it would require sizing down to a smaller wood stove to not eat up floor space (which I might be willing to do...just trying to figure things out).

 

[begreen]

We've been through multiple extended power outages with a small stove (Jotul F602 and F3CB). That convinced me to go larger. A small stove is ok for a 10-12 hr outage, but when they last for several days then you want a larger firebox for a longer burn. If you are comparing to a larger ZC then compare its value to a larger wood stove. That ended up being my preference and it has turned out well, both for power outages, but also for house heating in general.

 

[jetsam]

Follow up question. Seems like the consensus is heavily towards wood stoves...for a power outage scenario, would you rather have a small woodstove (Morso, Jotul F3 or Hearthstone Craftsbury) than a much larger EPA ZC like Flame Monaco/Osburn Stratford? Asking more about effectiveness of heating...I know burn times will be short. The relevance of the question is that it would require sizing down to a smaller wood stove to not eat up floor space (which I might be willing to do...just trying to figure things out).

Don't forget semiflush inserts as an option. Mine heats very well without power- in fact, I often don't even turn on the fan unless it's below freezing outside. BUT- before you start picking inserts or ZCs... see what you can fit in there. Some ZCs don't allow you to put an insert in them, which means ripping out the ZC and setting up the area for a new ZC or stove.

Small woodstoves wouldn't work for me personally with or without power- I need to be out of the house for 12 hours plus for work, and I'm too spoiled to want to heat up the house from 45 degrees every time I walk in. I also like to go to bed and sleep until the next morning. A small stove heating a large area is possible if someone is around and willing to keep feeding it and burning down coals, but even if they don't have a job other than stovetender, they still have to choose between cold house in the morning or getting up in the middle of the night to feed the stove. This is not a rhetorical exercise for you- you have almost 1700sf with some 10' ceilings.

So yes, if you want to install a small stove, I guess you could heat that space during an outage as long as you have someone to feed it regularly, and the space is fairly well insulated. I wouldn't want to do it, though. Plus if you get a stove that is sized appropriately, you can use it to heat all winter, not just during outages.

There's also the psychological aspect- what is OK is just a matter of what you're used to. We used to bank the fireplace and the woodstove for the night and wake up with a glass of water iced over on the bedstand, and that was just fine (rather nice actually, with a proper amount of quilts). These days I am grumpy if it's slightly below 70 when I wake up, but that's OK because now we have EPA stoves that burn for more than 4 or 6 hours.

 

[kennyp2339]

Yes, the star is also the current location of the superior. That currently has an outside air vent that goes up to the roof. I've seen some manuals want outside air further away from the chimney. Below is a finished basement, so out the roof is probably the only choice (or no outside air and cracking a window).

Unfortunately you cannot run an oak parallel with the chimney, in the event the chimney gets clogged or blocked the oak will act as a chimney and its not rated for that, the best bet is to figure out the way your joist's run in the basement, even if its finished you may have a direct run to the outside and may only need to cut a small hole in the sheet rock.
If the house is super tight as your saying fresh air combustion air is a must or every time you reload smoke will be rolling out into the living space, plus poor overall performance of the stove in general.

 

[begreen]

Don't forget semiflush inserts as an option. Mine heats very well without power- in fact, I often don't even turn on the fan unless it's below freezing outside. BUT- before you start picking inserts or ZCs... see what you can fit in there. Some ZCs don't allow you to put an insert in them, which means ripping out the ZC and setting up the area for a new ZC or stove.

This is a remote possibility. If interested, check the Superior's manual to see if an insert is permitted or provide the make and model here and someone will look it up.

 

[overlandsea]

Unfortunately you cannot run an oak parallel with the chimney, in the event the chimney gets clogged or blocked the oak will act as a chimney and its not rated for that, the best bet is to figure out the way your joist's run in the basement, even if its finished you may have a direct run to the outside and may only need to cut a small hole in the sheet rock.
If the house is super tight as your saying fresh air combustion air is a must or every time you reload smoke will be rolling out into the living space, plus poor overall performance of the stove in general.

Makes sense. I've noticed manuals have vastly different instructions for OAKs. Some don't really give any guidelines. I've seen some allow 10' rise max with a 15' chimney. Would it be possible to go up 8 feet and then horizontal through the attic closer to the edge of the roof?

 

[begreen]

Makes sense. I've noticed manuals have vastly different instructions for OAKs. Some don't really give any guidelines. I've seen some allow 10' rise max with a 15' chimney. Would it be possible to go up 8 feet and then horizontal through the attic closer to the edge of the roof?

Most likely not, but this will depend on the final product choice. Through the basement to an exterior wall is what most stoves will require if the house is tightly sealed. Note that some stoves don't have an oak connection option.