Regarding a central air dump from stove...

[Snagmaster]

Hello all,

I've been parusing the forums and have seen some items which helped, but the responses are all from several years ago so here goes:

Currently in the process of a new build and have chosen a focus 320 clean face for install on the main floor of a 4 level split. Now we will also have a ducted heat pump (3 zone) as the "primary" source for when away. I've been given two options for the stove as to additional venting: first, the central air dump that would go to the intake prior to the heat pump. The second is a fan box with smaller ducting to 4 - 5 rooms ( basement rooms) with one thermostat controlling the fan for this.

A few things about the home that are important to consider are that the floor sizes are not equal: the main floor has a larger square footage with the associated basement below. The side split levels (one up and one down from the main floor) are smaller and house the bedrooms so are planned at a lower temp in evenings. The fireplace is in a large cathedral ceiling room and the installer for the central air has planned on an air return towards the ceiling to draw the heated air into the ducting. Most of the ducting will be in between the floor joists and in internal walls.

Now personally I am thinking the 650 cfm fan into the intake ducting along with the return in the ceiling of the main room will help spread the heat throughout the home and will give better control when we adjust zone temps. The other method will dump more raw heat into the specific rooms, but the one thermostat for 4 - 5 rooms leads me to believe that we may have over/ under heating issues. House is extra insulated for retention and has approximately 4400 square feet to heat including the smaller crawl space under the side split.

Advice and opinions on this with suggestions......and go!

 

[EatenByLimestone]

I think you will be asking a lot from a 2.6 cu ft stove. I'd go larger, if possible.

 

[WoodyIsGoody]

I think you will be asking a lot from a 2.6 cu ft stove. I'd go larger, if possible.

I think it's asking a lot to heat 4400 square feet with a single point heat source regardless of the size of the stove. Yes, it's possible with a well engineered, adjustable and integrated air handler but this is more the realm of a wood fired furnace or boiler. The house needs to be designed and built with this in mind, retro-fitting a good solution is often problematic.

In my experience, people want to enjoy wood heat and they do this by gathering around the heat source. Even a relatively small stove can emit a lot of heat. If the heat source is too large and too hot, nobody wants to gather around. I have seen far more installations where the stove is too large for the task at hand than too small. The particular design of the stove is more closely related to hourly heat output than the size of the firebox. Both are inextricably intertwined but firebox size is more closely related to length of burn.

I think it's more rewarding to maximize the heat output from a smaller stove than try to moderate the heat output from a larger stove. My advice is to try not to make a woodstove do something it wasn't designed to do (heat a large house with a single point source of heat).

 

[begreen]

The very large square footage combined with high ceilings mean that the best success will be using the fireplace as an area heater. It may work to heat most of the main floor and upper split when temps are mild and in the 40's but will need supplemental heating as the temperatures drop below freezing.

 

[Snagmaster]

Sorry all, I guess I phrased that incorrectly. I didn't mean to imply that the focus would be heating the home completely. I should have said the ducted heat pump will be supplemented by the 320. I just want to to be able to spread as much of the wood heat throughout the home by the best means possible.

 

[Snagmaster]

Thought I'd drop a quick update on things: took the Focus 320 and added a heat dump option to the basement hall. Main return for the central air is in the peak of the main room. It's -12°C and going down to minus 18. So far the stove has been doing a great job holding it around 20 to 22 inside. Heat pump kicks in when colder a bit but otherwise its doing great. It is definitely heating the bulk of the house. When it drops to -30 I know it will struggle, but still!

I've got the bug now......I want another stove in the garage!

 

[Ludlow]

Drolet heatpack

 

[Snagmaster]

4 years later:

This 320 has been handling the bulk of the heating. Since the room it's in is high ceiling 'd with main air return and the heat dump to the basement, it never over heats. Only one section of the home gets cooler, and that's mainly airflow. Otherwise it works. I do agree that a larger unit meant for 3000 Sq ft would have handled it better on those very cold nights, but this unit has worked well. First year the wood wasn't fully cured and it showed. Much better now. Over night burns in the dead of winter are a little shorter - I load north south as the 320 is wider rather than deeper - but I can't complain. Burn hot in the morning to clean the chimney - very little ash come sweeping time.

Thanks for the advice all!

 

[EatenByLimestone]

Thank you for letting us know how it's working out!

 

[begreen]

Good to hear that it is working out. RSF makes good fireplaces and dry wood makes all the difference. Did you mean that this is an E/W loading firebox? N/S is when the wood is parallel to the sides of the stove.

 

[Snagmaster]

I dont use 22" logs normally. they do make a nicer view but since the firebox is wider than deep, I push the coals to one side and load 16" (approximately) wood N/S. I read the trick of pushing the coals to the back of a deep stove so that way it burns back to front, and adapted it for my stove. I can load more into it for the overnight burn with the draft closed. Do it around 10 pm and she's good for 8 hrs. I don't find I can get burns much longer than that. I've read about some who can get up to 36, and I'd love to get that, but I'm realistic.

 

[stoveliker]

The 36 hrs often won't give you the heat input you need in BTUs per hour. A 3 cu ft firebox can only hold so much BTUs (wood). Spreading thos BTUs out over 36 hrs is rather low. Unless your home is super insulated, I suspect a Canada home will need more heat most of the heating season.

 

[Snagmaster]

Oh yes. 8 hours is fine by me, considering it's heating about 4500sq ft. It's doing a stellar job though. Extra insulation during the initial build was worth it.