FPX44 Inside vs. Outside Air draw for blower

[ironmanco]

Another thread calls out some questions about my blower location. I'm in the process of trying to move my blower from inside the same room (literally next to the fireplace) to an outside wall. This is going to be a pretty involved process (siding, sheathing demo, etc) so I want to make sure this will all work.

I'm located along the Front Range of Colorado (near Boulder) and was wondering what I'm going to compromise with pulling in unconditioned air?

Would be great to have some FPX44/36 owners in similar (or colder) climates weigh in on this.

Here is some temp data.

 

[ironmanco]

Just bumping this. Wondering if some of the FPX44/26 peeps can chime in and tell me if drawing outside air in climates like Colorado (Front Range not mountains) comes with any issues.

 

[Neumie]

I’m in northern MN but don’t burn with my 44 when it is below -10F. Not sure if there’s any real reason not to (when it’s around 0 it’s not different than when it’s 30). Only been using it 1.5 years so hopefully others chime in.

 

[willoweep]

I have a friend in Nederland (mountains of Boulder County) with an FPX 44 with the blower outside on the west wall of the house. It has a constant cold draft coming in around the fireplace when not in use. When the wind blows, the cold draft can be strong. We installed a wind guard over the blower this summer and it helps in the wind, not so much in the cold without wind. I have installed a few FPXs ‘down in the flats’, putting the blower in the crawl space or away from and below the fireplace has worked well. The wind is the variable here. You should have adequate combustion air from the intake air vents. Why introduce more cold air into your house, especially when it’s blowing 50mph outside? Pulling conditioned air for the convection blower makes more sense than cold air. The chart that comes with the install instructions has blower inside in the black area (north and mountains) and outside in the white area (south). Boulder County is right on that line. Consider all the elevation west of town, like 8000 ft of difference between there and the Indian Peaks 20 miles away. In an inversion like we had today, the pressure of the cold air stuck in the valley is strong. Move it to a different location inside maybe, but I’d recommend keeping it inside.

 

[ironmanco]

Good info. Having the blower on the west side in Ned with our winds that typically /come/ from the west could definitely prove problematic. In our case, we are considering mounting the blower on the east (leeward) side of the house which is pretty protected from most winds. We don't have a crawl space but we do have a finished basement but are concerned about the noise in the finished basement when the blower is running and we are there. We're toiling with that option since it's likely that we wouldn't be in the basement AND having a fire in the fireplace on the 1st floor.


Neumie - is there a reason you don't have a fire when it's -10 below?

 

[Neumie]

Neumie - is there a reason you don't have a fire when it's -10 below?

We have in floor heat and the fireplace prevents the furnace from running. The farthest rooms get awfully cold, and the furnace runs a long time when it finally cools off near the thermostat.

 

[webby3650]

I have a friend in Nederland (mountains of Boulder County) with an FPX 44 with the blower outside on the west wall of the house. It has a constant cold draft coming in around the fireplace when not in use. When the wind blows, the cold draft can be strong. We installed a wind guard over the blower this summer and it helps in the wind, not so much in the cold without wind. I have installed a few FPXs ‘down in the flats’, putting the blower in the crawl space or away from and below the fireplace has worked well. The wind is the variable here. You should have adequate combustion air from the intake air vents. Why introduce more cold air into your house, especially when it’s blowing 50mph outside? Pulling conditioned air for the convection blower makes more sense than cold air. The chart that comes with the install instructions has blower inside in the black area (north and mountains) and outside in the white area (south). Boulder County is right on that line. Consider all the elevation west of town, like 8000 ft of difference between there and the Indian Peaks 20 miles away. In an inversion like we had today, the pressure of the cold air stuck in the valley is strong. Move it to a different location inside maybe, but I’d recommend keeping it inside.

The blower has a damper in it that prevents air from blowing in when not in use. The screws that attach the duct can prevent the flapper from opening or closing. That might be the problem.
The cooling vents should have a trap bent into them to help prevent wind from blowing down, but it’s still a possibility. That’s most likely the cause of your cold air, the flapper being stuck open is also common.

 

[ironmanco]

Just a follow-up. Moved the blower to be in our chimney chase. It's pointing south and is IMMENSELY better wrt sound. We've been using the fireplace almost everyday most in the evening.