Pellet Stove

How a Pellet Stove Works

Without any doubt, the heat of the natural fire is the best option to warm our body properly and also help to maintain the room temperature comfortable for winter. For the ancient ages, woods were the main and only source of fuel for heat energy. But now people are aware of the bad effects of burning wood and looking for a more reliable source of fuel. In contrast to wood, wood pellets are becoming very popular as a fuel and it is considered as one of the finest sources of renewable energy. The popularity of the pellet stove is increasing dramatically because it is more environment-friendly than stoves, fireplace, and firepit. Pellet stoves emit less harmful gases than wood stoves. Moreover, the working mechanism of this stove makes it more secure for residential use.

Many of our visitors always ask “How does a pellet stove work”. Although it’s a very basic question, but, very important to know before you are going to use it. Before we start our discussion about the working mechanism of pellet stove in detail, we will give you a basic idea about the pellet stove and different parts of it.

What Is A Pellet Stove

Pellet stove is almost similar to the woodstove. The construction and working procedure are nearly analogous with wood stoves. The stove that burns specially made compressed wood or biomass pellets and transfers the produced heat to make your residence warm is known as pellet stove. Wood pellet is a real source of renewable energy. They are produced by utilizing residual waste wood or log of the sawmill, wood factory, or furniture factory.

Different Parts of Pellet Stove

The below picture will show you the different parts of pellet stove:

Different parts of pellet stove
Parts of pellet stove

How Pellet Stove Works (Step By Step Discussion)

Five simple steps will describe the working mechanism of pellet stove:

1. Pellets Feeding system

2. Combustion system

3. Heat exchange system

4. Ventilation system

5. Waste storage system

Pellets Storage and Pellets Feeding To Burn Pot

What you will learn in this section:

  • How will you store the pellets in the stove?
  • What is hopper?
  • How will the pellets feed to the combustion chamber?

Pellet stoves have a storage box, usually, located on the top, sometimes, the bottom of the unit under the burn pot is known as Hopper. Typically, pellet stove hopper is designed in such a way that it can hold 35 to 150 pounds of pellets. Depending on stove size, model, and heating capacity, the capacity of hopper also varies. More the hopper capacity means the more it can hold wood pellets and it runs long without any interruption. A pellet stove can be run continuously for 2 to 3 days without refilling wood pellets if your purchased pellet stove has a decent hopper size.

Generally, two kinds of pellet stoves are available depending on the feeding mechanisms of the hopper. They are known as Top Feed Hopper (feeds pellets from top to burn pot) and Bottom Feed Hopper (pellets are transferred to burn pot directly) respectively.

A motorize augur system works to transfer the pellets to the combustion chamber automatically. Auger may look like a long screw or long spiral chain, but, in reality, it’s a motorized device to transfer wood pellets to the burn pot where the actual combustion takes place. Basically, the auger is operated by a build-in solid-state control system or sometimes come up with a special thermostat controller.

Obliquely, the fire size of a pellet stove depends on how quickly auger disposal wood pellets from the hopper to burn pot. There is a special term that is used to understand how fast and how much wood pellets will feed in the burn pot, it is known as “rate of feed”. If the rate of feed of your pellet stove is 1 pound per hour, it will make a very nice and gentle fire that will last a long time but the heat output will be lower. Correspondingly, a pellet stove feeding at the rate of 5 pounds per hour will generate fire like hell!

Combustion System

What you will learn in this section:

  • How are pellets burnt?
  • What is the function of blower fan?

The combustion system of the pellet stove consists of an ignition system, burn/combustion pot, and blower fan.

The actual combustion of wood pellets takes place in this part of the pellet stove. To run the pellet stove in full swing, you need to light some pellets first if your pellet stove is not self-lighting/self-starting and doesn’t have an auto-ignition system.

Lighting pellet is not so difficult if you follow proper technique. We wrote a separate article on “How To Light Pellet stove“, you may check it.

When you have done the lighting of some pellet, turn the auger at full speed. But combustion will not take place properly if there is no adequate air in the burn pot as fire can’t burn without oxygen. Therefore, a build-in fan located near the burn pot assists the wood pellet stove to catch fire properly on wood pellet fuels by supplying air in the burn pot. Moreover, this blower fan also helps to raise the fire, particularly when you need extra warmth. The blower fan of the woodstove pulls the outside air via an intake vent and ensures the constant supply of oxygen inside the combustion pot or chamber. Both the self-lighting system and blower fan require the electricity to operate.

There are also other fans inside a wood stove which mainly aid the stove to distribute the heat properly all around. Sometimes you will not able to get enough heat from your wood stove. It mostly happens when your apartment size is very big and your wood stove is not able to distribute heat all around. It can be fixed easily by placing a wood stove fan. If you place a good quality heat power wood stove fan above the pellet stove, the heat distributing efficiency of the stove will increase dramatically. So, buy a wood stove fan if your apartment is large in size.

Also Read: Comparision between Pellet Stove And Wood Stove

Heat Exchange System

What you will learn in this section:

  • How is heat transfer to the room?
  • Why doesn’t pellets stove become hot?

The heat produced in the burn pot is dragged by an intake fan and after that a blown transfer the heatwave to the entire apartment or room. As the heat is quickly transferred to the room, the pellets stove does not get hot like a wood stove. You can touch the outer casting even the stove is operating. So you can place the pellet stove though you have a child(s) in your family.

Ventilation System

What you will learn in this section:

  • Why don’t you need a conventional chimney in a pellet stove?
  • What kind of gases a pellet stove produces?

Pellet stoves produce some harmful toxic fumes which may kill us if we inhale it for minutes. So, the stove comes up with a vent pipe that most of the time located on the back of the pellet stove.

The toxic fumes are transported outside of the house through this vent pipe (usually 3-inch) that works like a chimney.

A pellet stove produces some harmful and fatal residual gases like carbon dioxide; carbon monoxide, organic oxide, etc. so carefully exhaust the harmful gases outside the home and also make sure that the gases will not harm the neighbors of your society.

Related: Pellet Stove Vs Gas Stove: Which Is the Best

Waste storage system

What you will learn in this section:

  • What is ash pot?
  • Who ash is stored in pellet stove?

Ash pot or box is used to store the ash of burnt pellets. This ash pot is placed at the bottom of the burn pot. Pellets create very little ash. Like the wood stove, you don’t need to clean the ash drawer daily. Cleaning it once or twice a week will be enough.

Pellet stoves are very costly appliances that only a few can afford. It is not a good idea to use it without having enough knowledge about it. After reading this article, you have gained a proper knowledge about the working mechanism of wood pellet stove.

Hope you like so.

Reference: 

https://www.hometips.com/how-it-works/pellet-stove-diagram.html