pellet insert vs wood insert - not able to decide

[skamp]

I decided to go with wood simply because I plan on scrounging and was afraid of pellet costs rising.

 

[badger1968]

Granted I'm a Noob, but I think it's a lifestyle choice. I figured the costs would be roughly equal--and don't care much if they're not. I have no skills with small motors and the power goes out around here if a Racoon farts.
I had a blast stacking my first 3 cord and I can't wait to get my first chainsaw. Go wood! You know you want to!

 

[SteveT]

Ok, I guess it makes sense, but in practice this seems to ignore the amount of control you have with some of the fuel types. For example, I would think that the effect of a thermostat actually makes those btus be used more effectively. I'd argue the ability to deliver the heat when you need it has a big impact on overall efficiency of your house as a system.

Take an extreme example. Let's say we could get 100% efficiency from wood, but it would all erupt from the log in 1 second. The room would be very hot for a while, the house would leak energy faster (because of the higher differential inside vs out), and later when you needed warmth you'd have to burst another log. To maintain a minimum temp you'd have to keep the place much hotter than you like because you'd have no other means of control. If you could put a thermostat on the system which had enough control to keep the temp where you wanted it, the room would not be excessively warmed and the heat loss would be minimized from the house. In my mind, this gives an advantage to oil, gas, and pellets because they have much better control over heat production. I'm no expert and haven't thought about this before, just rambling.

Steve

Sure, in your example there would be a huge efficiency advantage in the oil-fired system. You look at part of the equation, i.e., that the thermostat controls the temperature swings, limiting heat loss. BUT, the frequent start/stop at the burner is very inefficient -- each time the burner is ignited it wastes fuel. So even a system that operates at good steady-state efficiency (say 81 or 82%) operates at lower overall efficiency. It is simply the nature of the beast; they are either full on or full off. During cold weather I can hear my burner coming on several times each hour.

A woodstove actually has better control. You can throttle the air flow (inlet or damper) so that you can control the burn. Coupled with the thermal mass of the stove itself you can get a a fairly even heat output over a long period.

 

[Geepop]

Cost of stove fuel is effected by supply, demand, production costs, and ease of use. If it involves little work to use it then everyone wants it and this ties into supply and demand problems. If there is only a minor difference between the cost of oil and say wood people will tighten their belts and go with oil because of the convenience and it's also less mess. I think Highbeam is right that pellets will be more susceptible to price increases in the future. Trees are very abundent and accessable. Getting them from forest to stove is many times more work so this helps lessen demand and increases abundance.

The wood to make pellets has to come from someplace (wood chips and limbs won't be enough) so eventually there will be fewer trees and firewood too will rise. In this area current prices being paid by mills have resulted in a lot wood going to mills that would normally have been turned into stove wood. With the price for diesel rising the wood harvesting outfits are going for top dollar. Pellet stoves are sold out and back ordered for months. Stove shops have had to cancel customers orders and some of those had already laid in supplies of pellets for stoves they will now not receive!

Here's another version of a energy cost calculator:
http://www.enviro.com/help/energy.html

 

[sl7vk]

We're in the Energy Age....

Don't know about where you live, but there aren't pellets made within 500 miles of me.... Diesel at 5 dollars a gallon..... Well you get the picture.

I can see trees here in the valley as far as I can see.

If I post an ad on craigslist to cut down trees for free, I can get all the "free" fuel that I want or need.........

Seems an easy choice.

 

[BJ64]

I agree with donatello.

Since the stove will be used in the upper part of the home, I will assume there will be some stairs along the way. Since a sack of pellets is nicer to tote than an arm load of wood up stairs I tend towards the pellet stove.

 

[granpajohn]

Take an extreme example. Let's say we could get 100% efficiency from wood, but it would all erupt from the log in 1 second. The room would be very hot for a while, the house would leak energy faster (because of the higher differential inside vs out), and later when you needed warmth you'd have to burst another log. To maintain a minimum temp you'd have to keep the place much hotter than you like because you'd have no other means of control. If you could put a thermostat on the system which had enough control to keep the temp where you wanted it, the room would not be excessively warmed and the heat loss would be minimized from the house. In my mind, this gives an advantage to oil, gas, and pellets because they have much better control over heat production. I'm no expert and haven't thought about this before, just rambling.

Steve

Steve, you are not just rambling, and you're getting to the very essence of efficient combustion.
(I once had a calculus professor who routinely would fall into this sort of talk. Long time ago, of course.)
Any solid fuel that can be pelletized can be made to burn at its peak efficiency without releasing too much heat energy. (In Steve's example, the log is basically a giant pellet.) Lately, we've seen coal crushed into smaller pieces to achieve cleaner emissions. "Microizing", I think is the term. Of course, the amount of energy needed to pelletize may economically preclude the resulting output for heating purposes. Imagine those garbage compactors some folks used to have in the kichen. If that machine magically made the trash into dry pellets, who wouldn't use one? This is what, I think, leads to corn, cherry pit, and similar stoves. The fuel is naturally pelletized.

Well, heck....now I'm the one rambling.

 

[LONDONDERRY]

Steve[/quote]

Sure, in your example there would be a huge efficiency advantage in the oil-fired system. You look at part of the equation, i.e., that the thermostat controls the temperature swings, limiting heat loss. BUT, the frequent start/stop at the burner is very inefficient -- each time the burner is ignited it wastes fuel. So even a system that operates at good steady-state efficiency (say 81 or 82%) operates at lower overall efficiency. It is simply the nature of the beast; they are either full on or full off. During cold weather I can hear my burner coming on several times each hour.

A woodstove actually has better control. You can throttle the air flow (inlet or damper) so that you can control the burn. Coupled with the thermal mass of the stove itself you can get a a fairly even heat output over a long period.[/quote]

As a fellow engineer, I'd have to say I'm not a believer in the steady state system. I'ver heard this before from a few others that leaving the thermostat for a oil heating system constant burns less oil. There is a steady state at the furnace point, but as the heat dissapates outwards through the house, there are losses everywhere. In order to have a true steady state system, the entire air volume from room to room would have to be equilibrated. this is never the case is a closed loop heating system. The room closest to the boiler or would have the highest temperature and the rooms furthest aways would be the coolest. Unless a house is made of layers of dewar walls.

 

[dsm1212]

Well, I just ordered a pellet insert instead of a wood insert mainly because to me it is a trade off between time and money. Time gets more valuable as you get older since you have less of it. I'm willing to put in a little extra effort to have a second option over oil, but all that cutting, splitting and stacking just seemed like too much of a time sink.

We have an oil furnace with a cold start boiler that is actually very new too. My understanding with that is to get the most efficiency you want it to come on for at least 45 minutes each time it runs. The only time I found I can really achieve this is when it is very cold outside (<10deg), but then it's hard to feel good about it being so efficient when it is using so darn much oil .

-steve

 

[savageactor7]

Well I wonder what kind of stove joesat78 decided on...hope we didn't scare 'em off.

 

[joesat78]

well, I was waiting to secure the fuel source. I was able to get 2 cords of well-seasoned hardwood for $150/cord - cut, split and delivered. I was stacking them the last 2 days. The guy who delivered was very friendly and promised me more hardwood when I require them even during winter for the same price $150/cord, again cut, split and delivered. He said the wood was cut in 2007 spring and it sure looks like it is seasoned.
Tomorrow is the big day for me - i've zeroed in on Regency I2400. Got a quote for $3150 installed with blower. I also was looking at Quadrafire 3100i, but decided against it as the dealer quoted around $4500 installed - which is a little more expensive for me at this time. will keep you guys posted. The only thing I need to confirm with the installer is whether they would be insulating the flue pipe. Does anyone have any idea on this?

 

[begreen]

joesat, you got a great deal on wood. If you have the storage area, I would get two more cords of wood. The dealer sounds honest and well meaning, but he can't predict what he will have in stock in 6 months. It's rare, especially during a cold season, that anyone has good seasoned wood for sale in the middle of winter. And this year the demand could be exceptionally high.

Best of luck with the installation. The I2400 should make a nice difference this winter.