This is exactly what I planned on doing at my house. I wasn't sure what size fan to use. I only really care about heating my bedroom and the bathroom upstairs. There is a floor joist that runs down from the stove to the bedroom and bathroom. How far are you moving the air from the stove? what size fan would you recommend? when you installed the intake, was the fan directly behind the register? Is the thermostat included with that fan or did you have to purchase seperately? Can you pm me the full list of everything needed for the project? I would greatly appreciate it as I have vaulted ceiling as well so it would be perfect...thanks!
I am running the ducting to 3 bedrooms. The furthest(and coldest in more than one way) is the master bedroom, it is about 30' from the intake duct. I bought 1/2" foam board that has thin foil on 1 side to make my intake and exhaust plenums. The intake utilizes a 12" x 12" filter and grate(a filter here is strongly recommended after plugging one in 1 season!). Then I ran 8" ducting to the fan somewhat centrally located to the 3 rooms (all of this is obviously in the attic). On the outlet side of the fan I built and mounted another plenum which has 3 - 4" outlets. Those run to 4" x 6" (I think) registers in the ceiling of the respective bedrooms. I used flexible, insulated ducting. I used a whole box to run the 8" from the intake to the fan, 25' per box I believe. It then worked out that a 25' box of 4" was just enough to run to the 3 rooms. Eveything but the fan and thermostat were purchased at the big orange box store.
I have learned that you really want to try and keep the length of the outlet ducts as close to the same to balance flow and noise. For my application, a 440 CFM fan is waaaay more than enough, probably 1/2 that would be sufficient, but I was sailing uncharted waters and took a guess thinking the bigger the better. Anyway, I ended up installing a fan speed control to slow the sucker down. As mentioned speed is not paramount, and the noise of all that air running through the register was a bit much....the fan is real quiet, but the rushing air is not when turned up all the way.
The thermostat is a great idea, in theory. Unfortunately it didn't work as planned. I used a 110V A/C thermostat and I think I either have it mounted in a poor location or it just isn't sensative enough. I think the latter is more than likely. The idea is that, say it is set at 70°. When the living room gets to setpoint, the thermostat thinks you want to cool it down, and turns the fan on. It should stay on as long as the stove is putting out heat and the room is more than setpoint. Once the fire goes out and the temp drops sufficiently enough, it will turn off the blower. I have since removed the T-stat and replaced it with the fan speed controller like you would use to control a ceiling fan. I may look into a real thermostat in conjuction with a relay to control the fan. I believe most home thermostats use 18V(?) to control relays to turn on/off the various HVAC systems, so there's a little more BS associated with installation of that system. My stove fan is also thermostatically controlled. When the fire goes out, usually about 3 or 4 AM, and the stove cools down to about 100°, it turns off. The the room temp will drop below setpoint and turn the fan off so you are not circulating cool air. That's how it works on paper.
I had the stove for 2 years before the fan and it was never real comfortable in the house. It was smoking hot in the living room and freezing in the bedrooms. Mama was not happy. The fan installation has really made a huge differance in the balance of the temp in the house. The kitchen and dining rooms are adjacent to the living room so the temp is not an issue there.
If there's enough interest I could probably drag my butt up there for some pics of my setup.
As if this response wasn't long enough.....
opcorn:
I did all this right before Christmas of 2008. I had
just completed renovating the living room, which consisted of scraping the popcorn texture off the ceiling, plugging the 9" square ceiling light holes, and installation of can lights, and a whole lot more. Anyway, the actual fan / plenum / ducting was done on Christmas eve. As I was traversing across the vaulted ceiling I stumbled and guess what....I made a new access point to the living room from the attic through my freshly completed ceiling.:jawdrop: I wasn't hurt physically, but a man will go through an enormous range of emotions when he has just ruined a project that took several weeks to complete. Nothing is better than blasting off to HD to get a sheet of sheetrock 5min. before the store closes and doing a little sheetrock on Christmas eve! Got the hole plugged before Santa showed up.
That's enough....