OK.
We have had a freestanding Napoleon NPS40 pellet stove installed in our house, without a fireplace surround, and in operation since autumn 2008.
Here's what we've found:
According to the owner's manual, the NPS40 (the precursor model to the NPS45 and the freestanding older sister to the NPI45) puts out between 8500 btu's and 42,500 btu's. The feed dial is connected to a rheostat that has a continuous feed rate between 1 and 5, with the preferred standard feed setting at 4 per the manual. The dial has a color gradient on it that gets darker at 5, paler at 1, and there is a bracket drawn to encompass the area halfway between 3 and 4 (there is no "3.5" on the dial) and halfway between 4 and 5 (there is no "4.5" on the dial.) The owner's manual says that the preferred feed rate of 4 is most efficient.
So I draw from this and the bracket drawn on the dial face that the preferred feed rate is between 3.5 and 4.5 on the dial, with the optimum setting at "4."
The owner's manual states that the burn rate is 1 to 5 lbs. per hour. The standard hopper capacity (without the optional hopper extension to add capacity) is 55 lbs. The owner's manual states that the maximum burn time for the stove is 55 hours- which corresponds to a burn rate of one pound per hour for the 55 lbs. hopper capacity.
The owner's manual contains several charts in the specifications pages. One chart indicates that the minimum number of btu's per pound of pellets is 8200 btu's.
The next two charts indicate that the burn rate for the NPS40 is 1 to 5 pound an hour. There is a caveat which indicates that small pellets will increase or decrease the stated burn rates and burn times by as much as 20% up or down, depending on pellet quality. The btu's per hour are stated as ranging from 8500 to 42,500 btu/hour.
All indicators point to Wolf Industries (manufacturer of Napoleon products) using 8500 btu's/pound of pellets and a one pound per hour feed rate per the dial number on the feed dial, i.e. a feed dial setting of "1" puts one pound of pellets in the burn pot per hour, which yields 8500 btu's of heat into your house. A feed dial setting of "5" puts five pound of pellets in your burn pot per hour, which yields 42,500 btu's of heat into your house. One could surmise that at the corresponding settings on the dial, the corresponding pounds of pellets are being delivered to the burn pot.
I can tell you for a fact that at a feed rate setting of 4, we are NOT burning 4 lbs. per hour.
You will find a thread on Hearth.com in which I and a bunch of engineer type Hearth.com members did a study on my pellet stove, trying to figure out exactly what our rheostat was doing and how many pounds of pellets were being delivered to the burn pot per hour. It's my thread and even I can't remember right now what we came up with- I'd have to search and look. But I can say for sure that at feed rate 4, this stove does not deliver 4 lbs. of pellets to the burn pot per hour, so it's not putting out 34,000 btu's of heat into my house.
At a feed rate of 4, and I'd have to go back and look at my thread to refresh my memory about our numbers, but it seems to me that we were at or near 28 hours burning a hopper full of pellets. That's 55 lbs. of pellets in 28 hours, or just under 2 lbs. pellets/hour, or just under 17,000 btu's hour.
I and the engineers actually did a timed study in which I counted the time in which the rheostat turned the auger in our pellet stove- and I need to go back and look at that study. I sent the results to the engineers at Wolf Industries, and we had an email exchange about it, and then they just sort of went away. I didn't hear anything else.
The stove is long out from under manufacturer's warranty so that couldn't help us. The stove shop from whom we bought the stove changed hands and stopped carrying Napoleon products, so that doesn't help us either.
I'm trying to remember why we didn't simply replace the rheostat on the feed dial at our own expense. I honestly can't remember why we decided to let it go, except I think we may have decided that this is just our stove, this is what it does, and short of replacing it with another stove, it's what we've got. I'm back there now- thank you for refreshing my thought process here- and I'm going to go look at that thread and figure out what we want to do now with this pellet stove and that rheostat. (You will see from my signature that we have another place in which we've recently installed a wood stove in anticipation of retiring there in a few years- so yeah, other stuff was going on simultaneously.)
EDITED TO ADD: I did find that old thread, and based on semi-scientific research we determined that the duty cycle on the rheostat was as expected, i.e. the rheostat was turning the auger for the appropriate number of seconds on each rheostat setting. So this means that even though rheostat is powering the auger motor for the appropriate time intervals, the amount of pellets being delivered into the burn pot do not necessarily correspond to the number of pounds per hour as indicated on the dial. Fewer pounds per hour yields less btu's.
It took about 22 hours to burn one 40 lbs. bag of pellets at setting 4 on the dial, which corresponds to about 1.8 pounds of pellets burned per hour, which corresponds to 15,300 btu/hour heat output optimally at setting 4. If we assume that the setting of "4" should deliver 4 lbs./hour to the burn pot, then we should be getting 34,000 btu's/hour at 100% efficiency. Knock off 20% due to "small pellets" or whatever and we should still be getting 27,200 btu's/hour.
According to this review from WiseHeat.com added to their site on October 23, 2008, "Napoleon does not describe the stove's overall efficiency." (broken link removed)
According to Popular Mechanics, pellet stoves range from 78% to 85% efficiency.
So, if the optimum we can hope for at feed setting 4 with 8500/btu's hour out of premium pellets is 34,000 btu's, and the lowest end efficiency of the average pellet stove is 78%, then we could expect perhaps 26,520 btu's/hour. Decrease that btu figure by 20% for "small pellets" and feed setting 4 should still give us at least 21,215 btu's/hour. You can see that by using Napoleon's own numbers, we aren't getting anywhere near those btu's burning 1.8 lbs. of pellets per hour at the recommended feed setting of "4." At 8500 btu's per hour, which Napoleon uses in its specs, we are getting 15,300 btu's max- assuming that the stove is running at 100% efficiency and realistically it's not. It's most likely running at 78% to 85% efficiency just like Popular Mechanics predicts of most pellet stoves.
All that being said-
The Napoleon is a good, basic stove. It does what it's supposed to do (aside from my feed dial rheostat issues- or auger issues- I can't remember what we decided and why I simply didn't order a replacement rheostat- need to go look.) It's easy to clean, it's easy to maintain. The cast iron burn pot is one of the best in the industry. That burn pot will be here when I'm gone. That being said- the Napoleon's burn isn't like everyone else's burn. The burn pot is deep and round and it will reward you with a clinker that must be cleaned out daily if you are burning too rich/without enough air. You will soon learn to open that damper. The stories you hear about people burning their pellet stoves for a week or more without touching them except to add pellets? In my experience, that won't be you. The Napoleon's deep round burn pot with the pellets dropped in from above needs to be emptied just about daily. If I'm going to shut the stove down and let it cool long enough to handle the burn pot, I'm going to vacuum it out with my ash vacuum while I'm in there. Fortunately cleaning out the fire box in the Napoleon takes about five minutes max with a good ash vacuum.
People use ShopVacs on their pellet stoves and we did at first, too, but you need to let that pellet stove cool for HOURS to make sure you aren't sucking up an active ember into your ShopVac, which can catch your ShopVac and ultimately your house on fire up to hours later. It wasn't worth the stress or the downtime to us. We got a PowerSmith Ash Vacuum and we've never looked back. You can order a pellet stove kit for the PowerSmith but the most useful things I've found for daily cleaning are a typical shop vacuum round brush attachment and the typical crevice tool.
Get an Outside Air Kit. Not sure how that works with an insert but I wouldn't be without one with a pellet stove. The convective nature of a pellet stove means that fans are actively pulling combustion air out of somewhere. If the fans pull it out of your house, then outside air is going to come in from every crack and crevice in your house to replace it. The end result is that your stove will not keep your house as warm, because it's pulling cold air in from outside to replace the air it's using for combustion. If you have an Outside Air Kit (OAK) that will deliver combustion air from outside directly to your burn pot.
Tearing down the Napoleon NPS40 for a big exhaust path cleaning after each ton burned is relatively simple and straight forward. We have a direct vent (a horizontal pipe straight out of the side of our house with good clearances that comply with fire code plus a nice margin.) This makes cleaning the "chimney" as simple for me as waiting several hours to make sure all the embers are out and snaking an extra long ShopVac hose up the exhaust pathway from the terminal end outside literally into the stove from the opposite end. I do that about once a week during the burn season.
Your experience with an insert will be different. It will hold fewer pounds of pellets, 45 lbs. as opposed to 55 lbs., requiring more frequent refills. You will have to pull it out of the fireplace box in order to access the sides and to pull the combustion motor to clean your exhaust pathways after each ton. I cannot speak to cleaning the chimney but others with inserts can chime in on that. Do you have a chimney? or are you replacing a gas fireplace with no chimney?
IMHO, skip the ceramic logs. They look like ceramic logs. Nobody's gonna believe that you have logs burning in your pellet stove. It's just another thing to handle and move when you clean the firebox.
We've found the Napoleon to be an adequate pellet stove for the price. If I had it to go over, I'd probably invest more money and get a stove with a reputation of putting out bigger heat. Pellet stove heat is not like wood stove heat. It's gentler, more convective and less radiant. We need more btu's in this 1950's bungalow in the coldest part of winter. Depending on where you are in Georgia, the Napoleon insert may be more than enough stove for you. In town, in central VA, it's enough stove for us *most* of the time. At our other location, to which we will hopefully retire in a few years, no- the Napoleon would not have been enough stove.
To give you an idea, we are heating 1420 sq. ft. of somewhat chopped up space, but with a circular floor plan, with the Napoleon. The NPS40 is rated to heat up to 2000 sq. ft. Our other place is almost exactly 2000 sq. ft. and no, the Napoleon would not be enough stove in that house, based on our experience in this house.
And speaking of that, let me go find that thread in which we studied our rheostat to see if I just want to spring for a replacement now, before it gets really cold here, to see if that helps our feed rate.