What is a Pellet Stove?
A pellet stove is much like a wood-burning stove, but instead of logs, it burns pellets. Wood pellets are carefully prepared and dried to an ideal moisture content. This makes it easier to maintain a predictable burn and achieve optimal combustion. Because of that, pellet stoves for sale can be treated more like a central heating furnace than a traditional wood stove. This results in a more efficient, cost-effective appliance.
Their relatively simple maintenance procedures are another major appeal. Several models also regulate the burn rate automatically to maintain your desired room temperature. This can be done via a built in control panel and with some models, a wall thermostat or remote control.
Ready to find the perfect stove? You can start narrowing down your options by deciding what type of fuel you prefer and the size you need. You will also need to decide if you require a model that can operate without a conventional 120-volt power source. This will help you decide on the cost and maintenance you are willing to invest. Let's start with fuel.
Wood pellet fuel consists of byproducts from sawmill operations. Bark, sawdust, and other scraps deemed unsuitable for lumber are ground down, cleaned, and then pressed into special dies. This process produces specific sizes and moisture contents. The naturally occurring lignin in the wood fiber works as an adhesive of sorts, activated by steaming the pellet material during the cleaning process. When forced through a pellet die, the result is a very uniformly sized pellet with ideal moisture content, perfect for a controlled burn.
Some models allow other biomass material such as corn or cherry pits to be burned. But, you should always make sure that your stove accommodates these alternative fuels. Most models of pellet stove that are designed to burn these types of biomass will be labeled as "multi-fuel" models. Because shelled corn or grass pellets can be cheaper than wood pellets, it can be an enticing option. If your stove can burn alternative fuels, you may need to service it more frequently due to the higher sugar content which tends to create more ash and clinkers.
Types of Pellet Stoves
Pellet stoves come in two main varieties. The first resembles a traditional wood stove with a pedestal or legs and is designed as a room heater. The second style functions more like a furnace. It features larger hoppers and a system to force heated air to other parts of the home. Both styles work in a similar fashion and have similar components.
The hopper is a holding chamber for the pellets. Most hoppers fit within the body of the stove. Some models offer hopper extensions to increase the stove's fueling capacity.
Another important part is the auger. Most often powered electrically, the auger is a mechanical device. It draws pellet fuel from the hopper in the stainless steel burn pot, pushing them along the screw threads of the auger. The burn pot contains the pellets during combustion and contains air inputs along the perimeter for oxygen to feed the pellet fire. A grid or mesh in the bottom of the burn pot holds the pellets in place while letting the ash fall through to the ash pan.
Other major components of the stove allow for airflow and heat transfer. For instance, the combustion fan is the blower that supplies air to the flames for combustion. It varies output speed based on the amount of heat desired. It also pressurizes the vent system and forces exhaust air outdoors. The convection fan moves air through heat exchanger tubes. These tubes, positioned above the burn pot, heat the air passing through them. The clean, heated air is then expelled into the room. Because the exchanger tubes are completely sealed from the burn chamber, air quality is not effected.
Since the combustion chamber is sealed by steel and glass, smoke cannot enter the home. Instead, the combustion fan blows all smoke and light ash to the outside vent.
Electric vs. Gravity Feed
Most pellet stoves need electricity to power the mechanical components. In non-electric models, pellets drop into the burn pot through a gravity-feed system. Venting within the stove creates a natural draft that moves the air rather than relying on electrically-powered fans.
Electric — 120 Volt and/or Battery: Most electric pellet stoves rely on a constant 120 volt power supply. And, some models include a battery for backup during an electrical power outage. They are often configured as either a fireplace insert or as a free-standing stove. Inserts are retrofitted into an existing masonry or prefabricated fireplace. Like wood stoves, the main difference between an insert and a free-standing model comes down to a set of legs or a pedestal and how they are vented. These often take the place of a surround or flashing.
Another model option is the choice between top feed and bottom feed. Top-feed electric stoves drop the pellet fuel into the burn pot from above. Bottom-feed models feature a mechanism that pushes fuel into the bottom of the burn pot. Bottom feed models are slightly more desirable due to the fact that they reduce smothering of the fire that can occur when top feed models drop new pellets into the burn pot. That being said, newer top feed models have closed the gap on how much this plays into the equation.
Basic pellet stoves have a manually controlled electronic display. They only allow on/off operation of the convection fan and burn rate in preset intervals, usually low, medium, and high outputs. With these, you can turn the fan from low to high and adjust the burn rate as needed.
Other pellet stoves offer fully thermostatic operation with a built-in room temperature sensor. This type of stove will self modulate the burn rate and fan speed to maintain the room temperature. Many models of wood pellet stoves also allow the use of a remote or wall thermostat. These manage more accurate temperature readings from within the room. Connecting a thermostat or remote is a simple process and automatically bypasses the programming on the control board in most cases.
Due to their complexity, pellet stoves use several fail-safes and sensors for operation. Most stoves feature a hopper door lock or sensor to ensure the door is closed during operation. A vacuum switch, located in the intake air duct, makes sure the combustion fan is operating by detecting negative pressure. Lastly, a temperature sensor monitors heat output for the stove. This sensor shuts the stove down in the event of overheating.
Gravity Feed: Gravity feed pellet stoves are not as prevalent as electric models. Yet, they are refreshingly simple to operate and assemble. They don't need power! This makes them great options for remote, off-the-grid homes and cabins.
Designs vary, but most models are tall, free-standing stoves with a large heat exchanger. The exchanger takes full advantage of the flue gases produced by the fire, routing them back and forth through the exchanger body. This gives the exchanger time to absorb the heat from the flue gasses, radiating it to the room. These stoves are fully mechanical, relying on gravity to feed more pellets from a chute into the burn pot as previous pellets burn away.
How does it work? Pellets in the burn chamber create a blockage that clears as the fuel burns down. The clearance created during the burn allows more pellets to enter the chamber. An adjustable feed door or feed collar controls the feed rate.
Because these stoves do not have electrically-powered fans, they are vented like wood stoves. They rely on a natural draft through a vertical vent system.
Choosing Size and BTU Rating
When selecting a stove, you need to consider the physical dimensions of the stove and its heat output. This ensures it fits your desired space and produces enough heat.
The amount of heat produced by the stove is measured in BTUs (British Thermal Units). The lowest BTU output pellet appliances emit is around 5,000 BTUs. "Whole house" systems can produce upwards of 80,000 BTUs.
So how do you know what BTU rating is best for you? If you intend to heat the entire home, look for stoves with BTU ratings on the higher end of the scale. You will need to place the stove in a central location of your home. You will also need blowers and an air distribution system. These things help distribute the heat effectively.
If you plan to use the stove for a secondary heating source, you will want to calculate the volume of space in your room. Do this by measuring the length, width, and height of the space. Then, multiply these measurements together. Next, multiply your total volume by 20 to get an estimate of how many BTUs the room can support.
Of course, this is impacted by how well the home is insulated and ventilated. The climate you live in also plays a role. If you have more questions about BTU calculation, our expert technicians are sure to help.
Pellet Stoves vs. Wood Stoves
Are you on the fence between a traditional wood stove or a pellet stove? Well, there are several reasons to give a pellet stove for sale a closer look. We've outlined some here for a quick comparison.
Due to their moisture content and uniformity, pellets burn more efficiently and create less ash. They also allow for a wider range of burn rates without sacrificing ability. Sometimes the maximum burn rate can be too hot for a room or might use too much fuel. Because of this, you may want to burn your appliance at a lower and more comfortable rate.
Most wood stoves are much less efficient when burning at lower rates. This means they have less heating power and release more particulate pollution to the chimney, creating more smoke. Pellet stoves perform better. For example, you can burn pellet stoves at 25% of their maximum burn rating. They will still maintain a 15% better efficiency rating on average than a wood stove burning at the same rate.
Pellet stoves are also easy to operate. Many models even include a hopper that can regulate how much fuel is fed into the burn pot. That means no more stoking and tending to the fire throughout the day! As stated, pellets create less ash, and the design of the stoves make ash removal convenient.
But, unlike wood stoves, most pellet stoves need electricity to power electrical components. While this will not have a huge impact on your electrical bill, it's a big deal if you're planning on living off the grid. In this case, you'll want to look for non-electric models in the event of a power outage.
Another factor is installation and venting. Most wood stoves call for vertical venting, but a pellet stove can be vented horizontally, too. Plus, the blowers do away with the need for a chimney draft. Not to mention, installation is often cheaper for pellet stoves than for wood stoves.
Something else to consider is fuel. Pellet fuel tends to be cheaper than purchasing cords of wood. Yet, the pellet stoves themselves are more expensive than wood stoves. This means you'll have a larger upfront investment for pellet stoves than for wood stoves. This should balance out with the other savings, leaning more favorably for you over time.
Ready to start shopping around? Here are some of the industry's most popular and reliable brands:
- Pleasant Hearth — A part of GHP products, Pleasant Hearth makes durable, low-cost pellet stoves and other hearth products. Their appliances have proven to be a reliable heat source for many consumers.
- US Stove — With over 100 years of experience, you can count on a high-quality product from US Stove. They have an admirable collection of multi-fuel models, offering traditional and modern styles.
- Napoleon — Based out of Barrie, Ontario and starting as a steel fabricator, Napoleon has been part of the hearth industry for over 40 years. In line with their great reputation, they offer a limited lifetime warranty on their pellet stoves.
- Harman — Beginning as a wood stoves manufacturer in 1979, Harman has steadily diversified its line of hearth products. With pellet stoves in inventory, Harman stoves rank among the highest quality models available. They are built to an exceedingly high standard and known to be among the highest quality models available.
- Osburn — This Canadian based company has been producing quality hearth appliances since 1979. But, they became a leader in the industry after joining the SBI group of companies in 2002.
Pellet stoves ship via freight and delivered on a pallet. The freight company will call you to schedule a delivery time at your home or business. We recommend you inspect your package thoroughly for damage upon delivery. Some manufacturers have limited warranties. As such, they may only cover manufacturing defects identified within the first few days. By examining your package early, you can meet this deadline.
Additionally, freight deliveries often require more than one person to receive the package, due to the size and weight.
We strongly recommend having a qualified professional install your pellet stove. Due to all the mechanical and moving parts, these appliances are more complicated than they first appear. Even a handy homeowner should hire some assistance for installation.
Most pellet stoves use a 3 or 4-inch venting system, due to the small size of the burn chamber. For pellet burning inserts, you will need a flexible liner to re-line the chimney to the required diameter. For free-standing stoves, a special 3 or 4-inch L-vent pellet pipe is used. Almost all pellets stoves utilize a 3 inch vent collar, only requiring a transition to 4 inch venting if the pipe run will extend beyond 15 feet high or will have long horizontal runs. The venting of an electric pellet stove is under constant pressure from the combustion fan. So, almost all manufacturers allow vertical or horizontal venting. Such flexibility allows for more versatile installations. This is especially helpful when a complete vertical vent would be difficult or impossible.
With horizontal venting through an outside wall, it's best to install a short vertical section either inside or outside the home before terminating. Doing this ensures that electric stoves without battery backup continue to draft properly if power is lost to the combustion fan. Without the vertical section to produce natural draft, you risk smoke backing up into the home during a power outage since the pellets will continue to burn and then smolder.
Lifespan and Maintenance
As mentioned before, pellet fuel is finely ground and well-cleaned. However, even this thorough process can't extract all the impurities. Trace pieces of metals and other non combustible debris will end up in the pellets. These materials will often turn molten during the burning process, falling through the grid at the bottom of the burn pot. This "clinker" material collects in an ash collection tray once it has passed the grid and can be removed as necessary.
Because pellet stoves use a very dry fuel, they produce very lightweight fly-ash. It has somewhat of an adhesive nature. Thus, the ash can stick to the heat exchanger tubes or inside of the vent pipe. This reduces your stove's ability to transfer heat to the room and vent properly. For this reason, you'll need to inspect the cleanliness of a pellet stove more often than a conventional wood-burning appliance. Because the ash they produce is very lightweight, it is relatively simple to quickly wipe the ash from the heat exchanger tubes. Cleaning brushes with lightweight flexible rods also make it easy to quickly and effectively sweep the vent system.
Maintaining a pellet stove might seem intimidating, but their ease of use makes it worth it. Once installed, the stove will need some routine maintenance. This includes emptying and rinsing the ash pan daily or weekly, brushing the vent, and checking the igniter. During the offseason, conduct a thorough cleaning and remove the pellets from the hopper. Always make sure the stove is cool before attempting to clean it.
You should also use the correct fuel type for your stove to avoid excess ash which could cause clogging in the fan. Lower quality fuel will have a higher ash content.
Pellet stoves have a shorter lifespan than some of the other stoves and appliances. But, with proper maintenance, you can expect your stove to function well for 15 to 20 years.
The best way to maximize the lifespan of your unit is to read and follow the manufacturer's guidelines. It is possible to void the warranty by doing things that are not recommended in the manual. So, avoid any fuel or maintenance discouraged by the manufacturer.