I'm strongly considering putting a pellet furnace in. I got the wifey "OK" this morning, so now it's up to me. I have room in the basement utility room, I have a forced air LP furnace I can duct into, but I'm having issues with the potential venting. The furnace will be placed in the utility room in my basement, which offers a great location for everything except the venting outlet. It will vent on the south side of my house. There is a single, open-able window on that wall of the basement. I can get two joist spaces to the side of the window, and if I come out through the rim joist I will be above the window. I'm confused on the whole "distance from the window" thing. Where do I measure? The center of the vent to the center of the window? Closest points? Why the clearance requirements? My basement windows are probably more airtight than the building envelope of the house, provided I'm smart enough to keep them shut. Clearance from the window is the first problem. The second problem is the fact that the venting would be approx 4 feet to the west, and slightly below the patio door. We don't use it much in the winter, mostly to let the dog in and out, but still open that door occasionally. Will we get a blast of hot, ashy air every time we open that door with the vent that close? Four feet allows for some dilution, but I don't want to let a bunch of exhaust gas in the house every time we open the door. Prevailing wind in the winter is usually from the southwest/west. I'm considering the PF 100 or the Fahrenheit 50F. Leaning towards the PF 100 because I know that will easily heat the whole house (2400+ sq ft) and I can sell the CPM to make up some of the cost. Not sure on the 50F. Would probably have to keep the CPM for the bad days, not to mention I have a lot of duct work for a 800 CFM blower. Thoughts on the venting?
Well, I will start with the windows. If it's inoperable. Or can not be opened (if you screw it shut) then the 4 ft clearance does not matter. And as for the door, you would have to take a pic. My Fahrenheit exhaust is within 12 ft of my back door (north side) and I can smell it when I open the door, but it's not overpowering at all. Actually, the smell of a burning pellet stove (a good/clean burning one) is one of my favorite smells. If you have the wife's go ahead ? Then by all means, get the PF-100! The Fahrenheit would prob heat your place (even without the CPM) but it would have to run pretty hard (level 5). I have mine on level 4 again for the 2nd time this year. Level 3 was getting it done, but it was never going into Pilot. It was just running on level 3 constantly. Never giving the furnace a break. How long will your Horizontal run be from your utility room?
The horizontal run would likely be about 12 feet by the time it gets from the furnace to outside the house. Add two elbows, and I'm over the 2o feet that Fahrenheit suggests. I could place it right next to the wall, which would really shorten and simplify the venting, but then I'd need a big duct across the room to get to the main trunk of the ductwork. Not a deal breaker, but a disadvantage none the less. I'm no expert, but it seems to me that more duct work would eat up even more of the already sparse 800 CFM...right? The PF 100 is a bit more tolerable of a long exhaust run per the manual. The only problem is finding a decent used one. There is one on Craiglist right now that looks great, but it's 4-5 hours from here, and my work schedule is not favorable. Wifey is onboard, but I don't think she'd be thrilled with the 5K+ price tag of a new one. If I can score a decent used one for 3K, that would be fine.
Ok. Update time. I've crossed the Fahrenheit off the list. I'm pretty sure it's not enough BTU, and the blower probably would not be enough either. I'm between the PF 100 and St. Croix Revolution, and leaning towards the Revolution. The 60K BTU and 1000 CFM blower should be enough to keep the house toasty. I'm afraid the PF 100 would be too big, and spend most of it's time idling and sooting up, not to mention devouring pellets. By the way, the Revolution is also at least $1500 cheaper. I'm planning on keeping the CPM for the first year or two to see how it goes, just in case. Unfortunately for me, there is no local dealer for St. Croix. OK, there's no local dealer for anything. The Harman dealer is 40 miles away, and I don't know if they would come here for service if needed or not. The closest dealer for St. Croix was very helpful over the phone, and said he'd be happy to help over the phone, but they won't come to my house other than the install because it's too far. How much of a problem is that? The other odd thing was that he said most people don't hook into the cold air return. Why not? It won't save that much money, and it seems like the air flow would be much better. Thanks.
Cold air return will eliminate heating your basement and making your upstairs a closed loop. Heat goes upstairs and cold air return comes from upstairs. Otherwise, the basement steps become your return and you have to warm the basement. I don't have a return. But my wood stove keeps my basement warmer than upstairs.
Hurry up and do it before she changes her mind or asks how much!!! Seriously consider heat loss in the duct work among one of the deciding factors. You have to move that heat a long way and if you push it too hard, it'll cool down more quickly. I know little of either unit in question, but if space and budget allowed I'd opt for the highest btu output and most user control. My furnace is all analog control and although fairly new, it's really quite antiquated and simplistic in design. I have the best luck maintaining a lower level fire a moderate blower speed (controlled by rheostat) for a constant low and slow heat delivery. It's kinda like having a boiler but forced air instead? Low and slow and nothing cools down.
+1 regarding ductwork heat loss. I noticed a huge difference after insulating my supply ducts, especially at the far end of the run. The half of the basement my trunk lines run through is uninsulated. It was a tedious PITA job, but was worth it. 'Low and slow' is the reason I hardly ever run the furnace on t-stat mode. I like the constant heat, not the temp swings.
Dex - the basement door is always closed because I have small kids, and don't trust them with complete access to the basement yet. I assume I'd have to keep the door open if I wanted to heat the basement then? BUT... I do have two ducts supplying the basement, and a single hole in the cold air return, albeit on the main trunk. Still probably better to tie in the return air, right? 343 - How did you insulate the ducts? I'm also in the process of finishing the basement (and laundry room and work out room and...TOO MANY PROJECTS AT ONCE) and am about to enclose the duct work. Probably best to insulate first...pics would be great.
Before I insulated I used foil tape to seal all the duct joints. I couldn't believe how much air I was losing at the joints. My house was retrofitted with forced air heat at some point in the late 60's/early 70's, as it was built with electric radiant heat, and whoever installed the ducts put them together and used a single screw to hold them in place. I also installed dampers in all my 6 inch branch runs, as not all had dampers. When I first hooked up the pellet furnace, the rooms at the east end of the house (closest to the furnace) were hot and the west end of the house was cool. I have the dampers closed almost all the way at the east end, and open most of the way at the west end. That seems to balance it out fairly well. I have to make the most out of the 800 CFM that the Fahrenheit has to offer. I started off using the foil covered fiberglass on my 6 inch duct runs. That was quite the PITA to install, so I switched to something that looks like foil bubble wrap. I'd read that the foil bubble wrap duct insulation isn't as good as the fiberglass, but the ease of install was worth it. If I was running through an unconditioned attic or crawl space, I'd definitely have kept up with the fiberglass as that has a bit higher R value than the bubble wrap style. My longest horizontal 6 inch run is about 12 feet, so I wasn't too worried about R value, mostly just covering the runs with something to keep heat loss to the 60-64 degree basement to a minimum. I'd also located some "dead end" ducts that I'd left in place after a kitchen remodel. I'd moved the floor registers and installed new runs when I did the remodel, but capped the ends of the old branch ducts and left them be. Those were above a drop ceiling in the finished side of the basement, so getting them out wasn't a big deal. I should have done it right the first time and removed them, but that would have been too easy.... The trunk runs were more of a challenge. I laid fiberglass batts on top of the trunk line. I then boxed in the trunks with rigid duct liner board and used a couple self tapping screws per section to attach it to the metal ducts. The only place I didn't do that was on the plenum right above the oil furnace. I foil taped the joints on the board and all is well. I didn't take a measurement of air temps before and after I did all the work, but it sure felt a lot warmer, especially on the far end of the run. The whole project set me back somewhere around $300 or so, but it was worth it. I noticed my electric bills were a bit lower in the summer also, presumably because I took care of a lot of the leaks in the ductwork.
Keep the exhaust as short as possible. Make sure your duct work can handle the air flow. No use spending the money on the furnace if it is not installed correctly. ****Never connect into the air return duct of your furnace**** You have to have back draft dampers installed if connecting to a heat pump or A-coil. Remember the Harman can burn over 13 pounds of pellets per hour. The biggest problem I have seen brands other than Harman is a warped firebox. This allows way to much air. Use a straight edge and check around the door. Clean filters make me smile. Eric
