Pellet Stove: A Brief History
After the discovery of fire, human beings relied on burning firewood as the primary source of heat. However, most of the heat was lost to the environment until reliable combustion chambers were invented.
The production of wood stoves by US Foundry in 1646 was the starting point of improving the efficiency of wood heat. These featured a metal casing that trapped the heat longer allow it to radiate slowly into the surrounding space. The stove revolutionized how people heated their homes.
Wood heat technology continued to experience more innovations. One of the most significant milestones was the innovation of pellet stove in 1983. The stove featured a technology that was considered safer and environmentally friendly than wood stoves. It was so clean that EPA did even not monitor its use.
So, how does the pellet stove work? Interestingly, they work in the same way as the wood stoves but with some few modifications. As a result, they are more efficient, convenient and safer.
WHAT IS A PELLET STOVE
Pellets are made from sawdust and waste wood. In most cases, they are available in 40-pound bags and measures a ¼ inch in diameter and ¾ inch long. They are considered to be environmentally friendly because the CO2 level produced is similar to the carbon released when wood decomposes naturally.
It is advisable to choose high-quality hardwood pellets from a manufacturer that is registered with the Pellet Fuels Institute (PFI). This will help to ensure that the stove produces hot and clean air.
The average household consumes around 2 or 3 tons of pellets per cold season. In most cases, a ton costs between $200 and $300.
DIFFERENT PARTS OF PELLET STOVE
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
Here we look at each component of the pellet stove and how they contribute to the production of heat.
Depending on the design of the pellet stove, the hopper can be located at the top, side or bottom. It is a large storage unit where the pellets are fed. This is the entry point of the pellets into the system.
The average hopper has a carrying capacity of between 50 and 150 pounds of pellets. However, there are larger stoves with a bigger carrying capacity. This means that stoves with bigger hoppers burn longer with fewer refills.
Nonetheless, the time it takes to completely burn the pellets depends on the size of the hopper and the rate of burn selected. For instance, if the stove is placed at optimum settings, the pellets will burn faster. A typical pellet stove placed at average settings will require refilling after every few days.
The auger is another major component of the pellet stove. It is responsible for the transportation of pellets from the hopper to the combustion chamber. This is considered the second step of the pellets in the system.
The design and size of the auger vary greatly. However, most of them are made from metal with a drill-like spiral design. The auger is powered by a motor that uses electricity. To improve efficiency, nowadays some pellets stoves are featuring battery powered motors instead.
The combustion chamber is where the process of producing heat occurs. There is a burn pot inside the chamber where the pellets are fed. The pellets are set alight by an electrical ignition and the combustion process begins.
Ultimately, the combustion process produces waste in form of ash which collects in the burn pot. Over time, the pot gets filled. You are required to use the lever to deposit the ash in the pan underneath.
Typically, the combustion chamber is lined with fireproof materials. Bricks and steel lining are the two most common materials used. In most cases, bricks are more preferred because they make the process of producing heat to last much longer.
Most manufacturers fit pallet stoves with heatproof glass to view the combustion chamber from the outside.
Heat exchanger and convection blower
Two of the most prominent components of the pellet stove are the heat exchanger and convection blower. These two components make the stove achieve maximum heat efficiencies of up to 80%.
The convection blower brings in cold air that is rich in oxygen. The air is blown over the flame to create more intense fire that produces more heat.
Produced heat is directed to the heat exchanger which is a metallic structure that conducts the heat. A blower or fan then blows the warm and clean air into the living space.
Some of the components in the pellet stove are atomized and powered with motors. They include the auger, convection fan, ignition, and blower.
As a result, most manufacturers produce stoves that are automated. They come with a remote control to allow the users to adjust the thermostat on demand.
In addition, heat output is controlled via buttons that typically include low, medium and high setting. Other stoves have a reset button that enables the user to restart the process.
Even though it is not a must for the pellet stove to feature a vent, it plays a fundamental role in how the stove works. The combustion of pellets produces toxic fumes and water vapour which must be eliminated.
The vent pipe is attached to the stove to direct the fumes away from living space.
Things you should keep in mind
Pellet stoves are slightly heavy. An average unit measures about 25 X 27 inches and weighs approximately 400 pounds. You definitely need some help when installing the stove in your house.
It is advisable to place the stove on a surface that is fire-resistant such as stone and tile. Therefore, if your room has wood, vinyl, carpet or any other combustible flooring, you should consider having a hearth pad.
Some manufacturers include an optional pedestal that enables the user to raise stove to a more comfortable and attractive height.
The specific type of venting to be used depends on the placement of the stove. If improperly installed, the vent can allow smoke and fumes to get back into the living space. For better aeration, the stove should be placed near windows and doors.