Gathering, chopping, and storing firewood or biomass pellets can be such a cumbersome task despite the love to light up the fire to create a heat source in the house and keep it burning, especially during winters. What is more, putting up the fire and determining when to put it out before going to sleep or leaving the house is another worry that many have to deal with from time to time.
Not to mention the fact that the smoke that emanates from the wood consists of various chemical compounds that can be detrimental to human health. The smoke released during combustion also results in air pollution and a reduction in indoor air quality. This raises the question, what can people who love or depend on an indoor fireplace do to address all these concerns?
The answer is quite simple and that is, getting a substitute that is not only environmentally friendly but also more convenient and cost-effective. This is the point the wood pellet stove comes in, simply because, it exhibits all these qualities. The wood pellet stoves share a similar layout to that of a traditional fireplace and wood-burning stoves, but that is as far as the resemblance goes.
Pellet burning stoves are unique modern electronic appliances that provide an affordable and environmentally friendly option for indoor heating. Let’s dive in and look at how pellet burning stoves work, the different types of pellet stoves, and their various advantages and disadvantages.
How do Wood Pellet Stoves Work?
1. Use of Electricity
The wood pellet stoves operation is dependent on electricity. The hopper is loaded with the pellets from either the top or bottom part of the unit. Inside the stove there is a long screw like part called the auger, it is responsible for getting the pellets to the burn pot after they leave the hopper.
The auger is a motorized device so the temperature of the stove is determined by its speed. The burn pot is then kindled from its housing in the combustion chamber. Inside the burn pot, the pellets are pushed under immense pressure to create a much hotter flame due to the high density and low pressure.
The burn pot mixes the air and fuel in order to combust and initiate the burning process. The burn pot works as the stove’s carburetor. The burnt pellets are then dropped down to the ash pot in form of ashes, the ash pot needs to be washed regularly.
2. Type of burning agent
The pellet burning stoves use a similar type of wood, the wood pellet. The pellets are major produced by sawmills as a byproduct, they are made by the wood shavings and saw dusts which are recycled. They have a similar resemblance to rabbit food, the wood pellets are very easy to produce and the process is very affordable making it very eco-friendly.
The rate of pollution is also very low, pellets can also be made out of corn and grass although these ones cannot be used in stoves specifically intended for use by wood pellets.
3. Convection as a means of heat
A pellet stove hits up a room through convection, unlike the traditional fireplace. Gas becomes less dense and lighter in high temperatures which makes it go above cool air, which is a lot heavier. Convection happens when air current, both hot and cool are forcefully combined, thereby releasing and transmitting heat in the process.
Cool air is sucked from the room into the burn pot by the convection blower then it passes over the fire. This makes the blaze fierier and the pellets to combust in a more effective and even manner.
4. The heat exchanger is used as a furnace
The heat exchanger is found inside the combustion chamber and it helps to ensure the outside of the stove does not become too hot to handle. Its central role, however, is to receive heated air and transfer clean air via the room blower into the house. Gas is then pushed out through a narrow pipe located behind the pellet stove by the exhaust blower.
The pipe can be connected to an outlet such as a chimney or a small hole leading to the outside. The exhaust blower works much better when the pipe is directed vertically, which makes the chimney a good solution for the installation. A thermostat is used to regulate how the auger feeds pellets into the combustion chamber.
Types of Wood Pellet Stoves
Wood pellet stoves come in two different types:
1. Insert stoves
When a fireplace is already available, an insert stove could be fixed to connect with the vents of the chimney in the firebox.
2. Free-standing stoves
Alternatively, one could get a free-standing stove as it comes with its own exhaustion pipe. Pellets are customized to come in different styles, sizes, and colors to suit the specific requirements of a home.
Wood pellets come in models with different modification but there are several distinct characteristics to tell them apart.
Characteristics of Pellet Stoves
1. Hopper location
Top feed models have their pellets laden from the top of the stove into the auger, which then goes into the flame down the tube. This ensures that hopper has a lesser risk of getting burned although the ashes usually end up clogging the tube. This is why they use low-ash pellets. Bottom feed models have the pellets introduced horizontally.
This gives them the advantage of using standard pellets because ashes tend to move away from the burning area when the pellets are introduced horizontally. The burn box needs less cleaning because the air inlets do not clog. They may not be as efficient as the top feed models.
2. Type of ignition
Manual ignition utilizes a flammable material like gel or liquid starter, the material is lit together with the flame, it is likened to making a fire in a traditional wood fireplace. The automatic ignition is initialized by a button which prompts the stove to push the pellets inside the burn pot and heats up the self–igniter.
3. Heat output levels
The pellet stoves are customized to suit the specific requirements of different room sizes. They produce different levels of heat. The heat levels standard measuring unit is the British thermal units (Btu). The unit is used to measuring levels in industries that specialize in cooling and heating. The majority of the models range between heat-producing levels of 40,000 to 60,000 British Thermal Unit (BTU) per hour.
Advantages of Using a Pellet Stove
1. It is easy to use and maintain
The pellet stoves contain a power modulation and automatic ignition which makes it very friendly to users. The models are different with some being controlled by room thermostat while others use remote controls. The technology is continuing to become more sophisticated as some of the models respond to commands sent via a mobile app or text message. Also because they do not produce smoke, there is no fear of creosote building up making it pretty easy to maintain.
2. It is highly efficient
When compared to the traditional fireplace, the pellet stoves are about 90 percent more efficient in their heating range. In terms of energy consumption and use, it is less expensive than electricity and fossil fuels.
3. Autonomy
When the hopper is inbuilt, the pellet stoves can be fully functional without much tending for about half a day when fully loaded. When a partial load of about 30 percent is introduced to the stove, it increases the time from half a day to one and a half days.
4. It is friendly to the environment
The stoves are built with a computer system that ensures clean burning. This leads to a very low ash content and very low carbon emissions as they are CO2 neutral certified. The burnt pellets produce ash content of about 0.5 to 1 percent. Pellet stoves also emit very low toxic chemicals and smoke compared to gas, traditional fossil fuel stoves, or wood. Furthermore, pellets are made from recycled materials, especially biomass waste like nutshells, wood, and sawdust.
5. It uses a convenient fuel
The stoves use pellets which are very affordable compared to other sources of energy, the pellets have had very stable pricing in the latest years. The pellets come all ready to use, they are packed in bags that are convenient to put in storage and stockpile.
6. Very easy installation
Pellet stoves don’t need complicated installing requirements like the traditional fireplace. Costly chimneys and vents are not needed. It only requires a vent pipe to let out burnt gases during burning. Besides, the installation of the vent pipe is very simple and easy and one can easily install it without the aid of a professional.
Disadvantages of Using a Pellet Stove
1. Maintenance
The pellet stove is very efficient, which makes a lot of people overlook what it takes to have them maintained. Every week the burn pot of the stove needs to be vacuumed. It also needs to be cleaned out quarterly and checked and serviced by a professional annually. It also has many parts like the hopper feed, temperature sensors, and blower fan that require regular maintenance.
2. Noise
The stove contains a number of motorized parts; the auger motor and the built-in ventilation system, which makes a lot of noise when the stove is in use. The problem is being sorted out gradually with the introduction of more modern and upgraded versions of the models.
3. They depend on electricity for operation
As opposed to the traditional fireplace, the pellet stove comes with an in-built computer system. This system requires electricity in order to operate, rendering the stove useless when there is no electricity.
4. Size of the flame is small
Compared to the woodstove, the pellet stove produces a flame that is relatively smaller. People have even termed it as unnatural and nervous.
5. The investment cost in a pellet stove is quite high
To purchase a pellet stove, one needs significant financial backing. The pellet stove retails at around 2,000 euros, it goes up to 6,000 euros depending on the model one may prefer to purchase.
6. Issue of plastic bags
Every time one buys pellets in about 40 lbs bag, it will definitely be packed in a plastic bag. So if the purchase is regular, it simply contributes to more and more plastic disposal into the environment; further complicating the problem of plastic pollution. However, this can be addressed by insisting on the packaging with bio-degradable plastic or reusable cloth bags.
References:
- Gulland, John. “Considering a Wood Pellet Stove? Do Your Homework First.” Mother Earth News, December/January 2006. http://www.motherearthnews.com/Renewable-Energy/2006-12-01/Considering-a-Wood-Pellet-Stove-Do-Your-Homework-First.aspx
- Vandervort, David. “Pellet Stoves Buying Guide.” http://www.hometips.com/buying-guides/pellet-stoves.html
- “Wood and Pellet Heating.” A Consumer’s Guide to Energy Efficiency and Renewable Energy. December 2008, U.S. Department of Energy. http://apps1.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12570
