- Pellet-fed wood stoves burn processed-wood pellets, fed electronically into the stove’s combustion chamber.
- The advantage of this type of stove is it has a steady, controlled fuel source.
- Disadvantage is the electronic controls will not operate if the power is out.
Heating and Cooling
Getting a handle on heating and cooling becomes simpler when you speak the jargon. In here, find commonly used terms to better navigate the HVAC world.
Pellet-Fed Wood Stove
Airtight Wood Stove
- Airtight wood stoves have a sealed firebox with a tight-fitting door
- An air intake damper allows air to circulate around the firebox and controls the rate of fuel consumed. It can be manually or thermostatically controlled.
- Provides slow-burning heat for a long period of time with little attention.
- Prone to heavy creosote buildup in the chimney and pipes because it is slow burning.
Box Wood Stove
- Box wood stoves radiate warmth through the firebox to the surrounding air.
- Draws air for combustion through the door.
- Door is not tightly sealed, has no damper control and releases a considerable amount of unburned gas up through the chimney.
- Stove paint touches up or completely refinishes a stove.
- Specifically designed for wood- or coal-burning stoves, and can withstand temperatures up to 1,200°F.
- Common colors include green, brown, blue, maroon and black, in regular and metallic finishes.
- To maximize radiant heat from the stove, use a flat black paint. It will radiate 90-98 percent of radiant heat. Shiny metallic finishes are less efficient.
- Stovepipes connect a stove to the chimney. Never use in place of a chimney.
- Should be 24-gauge metal or thicker (the smaller the number, the thicker the metal).
- Should be as short as possible with turns kept to a minimum.
- Inspect stovepipe regularly and replace every two or three years.
- Outdoor fireplaces are a portable, wood or wood-pellet burning heat source that can be used at home, on a patio or on a camping trip.
- Some can also be used as a grill.
- Some styles are enclosed and vent through the sides while others may include a chimney.
- Another variation is the fire pit, which is bowl-shaped.
- Gas stoves are ideal for those with little space to store wood or with the time to maintain a wood stove. Also better for heating smaller areas.
- Uses natural gas, so it is a reliable heat source when the power goes out.
- Flame height and heat intensity is easily adjustable.
- The direct-vent type is ideal for homes without an existing chimney.
- Chimney cleaners remove creosote, a potential fire hazard, out of chimneys.
- Soot destroyers can be used in wood-, gas-, coal- or oil-burning fireplaces. They come in a powdered form, cylindrical sticks or aerosol spray cans. They are sprinkled on hot fires.
- Creosote removers, a second type, crystallize creosote in wood-burning stoves or fireplaces. They are available in powder form and are to be sprinkled on cool fires.
- Round wire brushes are another type of cleaner. Use them in wood burning, airtight stoves and fireplace chimneys.
- Grates hold burning logs off a hearth.
- Prevents logs from rolling forward.
- Using a grate and andiron allow air to circulate and feed the fire, while ashes fall away from burning logs.
- An andiron is a pair of metal bars with decorative front shafts that hold the logs.
- Using a grate and andiron allow air to circulate and feed the fire, while ashes fall away from burning logs.
- Glass enclosures improve fireplace performance by controlling air intake, making the wood burn more slowly and retaining more heat in the firebox. Additionally, the fireplace pulls less warm air from the house.
- Allows user to leave the fire unattended.
- Allows a clear view of the fire while keeping smoke and sparks out of the room.
- Most have a built-in draft at the base to direct air to the bottom of the fireplace opening. This allows the user to easily start and control the fire.
- Mounts securely against the face of the fireplace and overlaps the opening.
- Fireplace sets are the tools usually needed for a fire.
- Contains a stand, fire poker, ash shovel and broom.
- Available in many different styles for a variety of décor options.
- Electric heaters plug directly into a wall unit.
- One type uses black heat, where heating elements have the heating wire wound around a porcelain insulator.
- Another type is the more-popular instant heat, which uses a ribbon element.
- Some models have small fans to force heated air into the room.
- Heating capacity is rated in BTUs. Wattage ratings of heaters can be converted to BTUs consumed per hour my multiplying the number of watts by 3.413 (the number of BTUs equaling one watt.)
- Radiant heaters direct infrared heat to the objects or people to be warmed.
- For short periods of time, these heaters are more energy-efficient than convection heaters.
- Usually has a wattage rating of 1,500.
- The heating element is encased in quartz or a metal sheath and has a reflector panel behind it to direct the heat.
- The quartz rods will periodically need to be replaced.
- Baseboard heaters are a convection-type heater.
- The heating elements are completely enclosed, so they are safe for use around small children, but they do not give off as much heat as other types of heaters.
- Has a removable, protective grill for easy cleaning.
- Available with or without a thermostat.
- Ceramic heaters are a convection-type heater.
- Uses a ceramic disk heating element.
- Ideal for spot heating.
- Lightweight and easy to carry.
- Safe alternative to other heating sources as they operate at temperatures below the combustion point of paper.
- Includes a washable filter to reduce air pollutants.
- Fan-forced heaters are a convection-type heater.
- Uses fuel and electricity to circulate hot air around the area to be heated.
- Fans blow a gust of warm air that is able to heat an area that would normally be too open or drafty to heat with another type of heater.
- Available in models that operate on fuel oil, kerosene or propane gas.
- Can supply from 35,000 to 60,000 BTUs.
- Use in work areas, such as garages and barns and open areas such as construction sites.
- Usually equipped with air and fuel filters to block contaminants.
- Floor-vent humidifiers replace standard floor vent registers.
- Provides humidity for individual rooms without the need for a plug-in humidifier.
- Uses a water chamber where homeowners can add water, which then passes through a wick filter and into the air when the furnace cycles on.
- Furnace-mounted humidifiers force dry air from the furnace through a saturated foam element or plate.
- Connected to the water supply, so it is refilled automatically.
- Another type sprays a fine mist of water into the heated air.
- Uses an automatic reset humidistat to adjust moisture output to compensate for weather changes.
- Evaporative coolers are also called a swamp cooler.
- Uses ice and cool water to cool and return moisture to the air.
- Ice and cool water is mounted on top of the unit. As the ice melts, cool water flows over a wicking material. A fan mounted behind the wick creates a cool moist breeze.
- Environmentally friendly as it uses little energy and contains no harmful chlorofluorocarbons.
- Crack a few windows to prevent moisture build-up on inside walls when using an evaporative cooler.
- Dehumidifiers remove excess moisture from the air by blowing humid air over cold evaporator coils in a refrigerator system.
- Moisture collects in a pan, and the unit will automatically shut off when the pan is full.
- A humidistat controlling the dehumidifier will respond to changes in moisture content and is necessary for efficient energy consumption.
Window-Mounted Air Conditioner
- Window-mounted air conditioners cool, circulate, filter and dehumidify the air.
- Ranges in size from small units with a cooling capacity of 5,000 BTUs (enough to cool a small room) to capacities as high as 12,500 BTUs.
- It is important that you choose the right size of air conditioner. An oversize unit will cool but leave a damp and clammy feeling because of high relative humidity. An undersized unit will not operate effectively on very hot days.
- Select by BTU rating, not horsepower. BTU is the actual cooling capacity of the unit.
- Determine the efficiency of the unit by dividing the watt rating into the BTU output. The unit must have an energy efficiency rating (EER) of at least 9.7 for models under 8,000 BTU/hr., and 9.8 for larger models. The most efficient models have an EER of 11 and higher. Each model should have its EER clearly marked.
- Most models should include window-mounting kits. Kits include sill brackets for extra support of the unit and side vents to ensure an airtight fit in the window.
- Make sure the unit is designed for the type of window you have. Most are designed for double-hung windows, but some are made or casement windows or for in-wall installation.
Portable Air Conditioner
- Portable air conditioners cool small spaces, usually 400- to 450-square-feet.
- Mounted on wheels for easy movement from room to room.
- Contains both the hot and cold side of the air conditioner in one unit. Is not permanently installed, but must be connected to some place like a window where the hot air can be vented. Most models contain window-venting kits that are easy to install and easily moved from one window to another.
- May be either single or dual vent. Dual vent models circulate clean air back into the room and generally cool more quickly than single vent models.
- Drip models have a tray that will need to be emptied every 24-48 hours. No-drip models may cost more but do not produce any excess moisture.
- Window fans use less energy than air conditioning units, and contain no chlorofluorocarbons.
- Brings fresh air into the room while expelling hot air.
- Typical size is 20 inches.
- Larger window fans require mounting kits and side panels. The panels support the fan and prevent air from circulating around and back into the fan, resulting in a loss of performance.
- Smaller units are easiest to install, as they come with the panels attached to the fan.
- Used to intake and exhaust, for bringing inside air into a room or expelling inside air out of a room. Better models have electrical reversibility, which allows the user to switch from exhaust to intake without turning the fan around.
- Floor fans can be moved anywhere in the home to provide air movement that will cool and circulate air.
- Sizes are generally 10 inches to 12 inches in diameter. They can be mounted in rectangular or round, hassock-type case.
- A hassock fan throws air outward and upward in a 360° direction.
- A rectangular fan will tilt about 170° and may be used as a table fan, throwing air outward.
- Typically has a speed-selection control, while some may run at a fixed speed.
- One variation is the stand-mounted fan. This type can generally be easily tilted and may be used as an exhaust fan if placed near a window.
- Oscillating fans move back and forth in an adjustable pattern to spread air over a larger area.
- Oscillation function can generally be switched off with the turn of a knob.
- May be used on the floor, a table or mounted on the wall.
- Usually does not have as high an air delivery as floor fans.
- Typically ranges in size from 8 inches to 16 inches in diameter.
- Tilt angle varies from about 50 degrees to 90 degrees.
- Exhaust fans extract stale air from an attic, kitchen or bathroom.
- Kitchen fans are installed above the kitchen range or under the range hood and prevent smoke and grease from accumulating in the kitchen and spreading throughout the house. A switch simultaneously starts the fan and opens an outside vent.
- Bathroom fans may come with an optional light or heater and are used to expel steam and odors from the room.
- Should carry certified sound ratings developed by the Home Ventilating Institute and its member manufacturers. Ratings are in steps of 0.5 sones and 10 (CFM) cubic feet per minute. Limits for sound outputs are 6.5 sones for bathroom fans and 9 sones for kitchen fans up to 500 cfm.
- Digital thermostats control the temperature in a room turning on or off the furnace or air-conditioner.
- Temperature is set electronically.
- A popular type is a programmable thermostat that allows the use to preset temperatures for different times of the day.
- A popular replacement for dial thermostats because they use the same wiring.
- Dial thermostats control the temperature in a room by turning on or off a furnace or air-conditioner.
- Temperature is set manually by a dial.
- One type is low-voltage. It uses power from a transformer that converts 120-volt power into 24 volts.
- Line-voltage thermostats are another type, and use the same power source as the units they control.
Permanent Washable Filter
- Permanent washable filters consist of a flat panel of woven synthetics.
- Considered permanent because homeowners can rinse it free of particles and reuse it.
- Should be rinsed every 30 days. Filter usually lasts 5 to 6 years.
- Some brands have an anti-microbial agent that inhibits growth of mold, mildew, bacteria and fungi in the filter.
- An electrostatic charge develops as air passes through the filter. The charge, however, varies with humidity and the furnace or A/C blowing cycles. This means some particles may fall off the filter, pass through it and re-enter the air stream.
- Electret filters are disposable.
- They are more expensive than other types of filters, but also remove more particles than other types of filters.
- Electret filters protect the heating and cooling system mechanical parts from dust, which helps extend its life.
- Electrostatically charged. Contains “sites” that carry a permanent electrostatic charge. Sites attract and capture sub-micron-sized particles, as well as larger particles.
- Captures large airborne allergens like household dust, pollen and mold spores.
- Also captures microscopic allergens like pet dander, smoke and smog. Some manufacturers produce models that can capture bacteria and particles that can carry viruses.
- Should be changed every three months.
- Impeller humidifiers spray droplets of water into the air.
- An inexpensive type of humidifier.
- Must be used with distilled water or with demineralizing tablets in the water.
- Whole-house fans draw hot air from the living area into the attic, where it is vented outside.
- Installation and operation costs less than an air conditioner.
- Keeps a gentle breeze stirring throughout the house and can make the temperature seem 2 degrees to 3 degrees cooler.
- Has louvers that open automatically when the fan is turned on and close when it is turned off to seal out outside air.
- Rated according to the measurement of cubic feet of air per minute (CFM) that it moves.
- Fans with variable-speed motors cool the house at higher speeds and maintain general air circulation when turned down.
- Ceiling fans create a gentle indoor breeze and support heating and air conditioning systems by using less energy than a 100-watt light bulb.
- Typical household sizes range from 36 inches to 52 inches. Some industrial models are as large as 56 inches to 72 inches.
- Many models combine the fan with a light fixture.
- Most ceiling fans have variable speed controls.
- Standard mounting kits are available for ceilings as low as 8 feet and close to-the-ceiling models can be used on 7½-foot- high ceilings.
- Blades may be wood, metal or plastic.
- Heavy-material motor housings aid fan efficiency as the additional mass gains more momentum, reducing the energy necessary to keep the fan in motion.
HEPA Air Cleaner
- HEPA air cleaners pass air through a filter to remove pollen, dust and other airborne allergens.
- Uses a high-efficiency-particulate-arresting (HEPA) filter.
- Often used in medicine, atomic energy and semiconductors because of their superior air-cleaning ability.
- Can trap as much as 99.97 percent of particles 0.3 microns or larger.
- Designed to trap allergy-causing pollen and mold spores, as well as filter out smoke and dust mites.
Electrostatic Air Cleaner
- Electrostatic air cleaners are best for whole-house filtration
- Filter consists of shredded polypropylene fleece that has been given a permanent electric charge to help attract and remove submicron-sized allergens.
- Does not remove gas molecules from the air.
UV Air Cleaner
- UV air cleaners use a HEPA filter, as well as ultraviolet light, to clean air.
- Also acts as a germ killer to remove viruses, molds and bacteria from the air.
- Some units have a pre-filter as the first line of defense against larger particles. It is the less expensive filter and extends the life of the more expensive HEPA filter.
Ionizer Air Cleaner
- Ionizers clean air by charging molecules of air, which helps make indoor air more refreshing.
- Ionizer technology in an air cleaner can also reduce static electricity and improve a filter’s efficiency.
- Fiberglass filters are designed to protect the heating and air conditioning system from large particles, heavy dust and lint.
- Protects furnace from larger particles and lint that enter the HVAC system.
- Most common type of filter.
- Fibers are not dense or electrostatically charged, so they cannot attract and capture smaller-sized particles.
- This type of filter should be changed at least once a month.
- Most common size for all furnace/AC filters are 20x20 inches, 20x25 inches, 16x20 inches, 16x25 inches and 14x25 inches.
- Electronic filters are installed in the duct system and clean an entire home’s air.
- Only operates when the furnace or AC blower is running.
- Typically must be installed by a professional.
- Electronic cells must be cleaned regularly.
- Pleated filters are a low-cost alternative to fiberglass filters, designed to protect the home’s HVAC system from dust.
- Made of a dense and efficient cotton/polyester material.
- The pleated design provides greater surface area to capture more particles than fiberglass filters.
- Smaller-sized particles can pass through the filter because fibers are not electrostatically charge and the media must be woven with spaces between fibers to allow adequate airflow.
- This type of filter should be changed every 90 days.
- Warm mist devices use a heating element to restore moisture to the air.
- The water surrounding the heating element is brought to near boiling, and a fan cools and distributes the moistened air, which is slightly warmer than room air.
- This type can be used with tap water and will not cause dust.
- Can be noisy and consumes more energy than other types.
- Evaporative humidifiers use a wick and fan to return moisture to the air.
- The wick is a honeycomb arrangement of cellulose paper with a large surface area.
- Operates by partially submerging the wick in the water while a fan forces air to pass through the upper exposed area, distributing absorbed water into the air.
- Wicks need to be replaced.
- This type uses little energy and is easy to clean. Some units can be noisy.
- Ultrasonic humidifiers use high-frequency energy to break water into tiny droplets, which are then dispersed into the air by a small fan.
- Quiet and use little energy.
- Has the potential of leaving a sticky white dust around the house if used with hard tap water.
- Can pose health risks if the unit raises the level of airborne particles in the air.
- For best results and to prevent pollutants in the air, use distilled water with this type of humidifier.
- Duct insulation minimizes heat loss and improves efficiency.
- Available either as self-stick vinyl foam with aluminum foil backing or in handy rolls of 1¼-inch thick fiberglass.
- A duct fan boosts the flow of air from a central heating system to areas in a house that are hard to heat or cool.
- Overcomes the added resistance of long duct runs.
- A prop fan type fits inside the duct.
- A squirrel cage-type fan has a motor mounted outside of the duct.
- Most models vent about 200 cubic feet per minute in 6-inch to 8-inch diameter ducts.
- Wired in series with the central furnace blower or operated by an auxiliary thermostat.
- Kerosene heaters use a wick, rather than a pressure-fed fuel system.
- Standard features include an automatic shut-off device to extinguish the flame if the heating unit is bumped or jarred, grills or guards to keep hands away from the surface and push-button battery-powered lighting devices.
- Some areas do not allow the use of this type of heater. Check with local government agencies.
- Only use K-1 clear kerosene fuel. Yellow or colored fuel will smoke, smell and hamper wick operation.
Non-Vented Gas Heater
- Non-vented gas heaters require no outside vent.
- Suitable for zone heating; is clean burning and inexpensive to operate.
- Uses an oxygen depletion sensor (ODS). This device shuts off the heater and the flow of gas to the burner if the oxygen level in the room becomes inadequate. An ODS is required on all unvented heating equipment.
- Infrared-type heaters of this type use a ceramic radiant or panel that is positioned above the gas burner. The ignited gas gives off a bright orange glow to produce heat. A screen-like guard protects the radiant plaques but they are not otherwise enclosed.
- Convection-type heaters of this type first warm the air, which then warms the objects. Has burners enclosed within a painted or enamel-coated sheet metal housing that has air openings on the top, front and possibly the sides.
Vented Gas Heater
- Vented gas heaters are vented outside.
- Available in medium- or high-output models, ranging from 25,000 to 65,000 BTUs/hr.
- Includes an enclosed radiating circulator unit with tempered glass.
- Designed to take up a medium-amount of space.
- Popular with consumers seeking to trim heating bills.
- Oil-filled heaters are a convection-type heater. It contains a factory-sealed oil reservoir that never needs changing or replenishing.
- Looks like a household steam radiator.
- A tubular heating element heats oil, which in turn heats the exterior of the heater.
- Slow heating, but able to provide uniform temperatures throughout the space being heated.
- Fireplace inserts are airtight fireboxes that can be inserted into fireplaces and mimic some of the effects of a wood-burning stove.
- Most types draw air from the room, circulate it around the insert and return warmed air to the room.
- Some units have blowers to help distribute the heat.
Vent Free Gas Log
- Vent-free gas logs operate with the chimney damper closed, thus preventing heat-loss.
- Has an adjustable input with a maximum of 40,000 BTUs.
- Any unit made after 1980 includes an oxygen depletion sensor (ODS) that shuts off the heater and flow of gas if the oxygen level in a room becomes inadequate.
- Another safety feature is an automatic shut-off valve to shut off the gas flow if the pilot light is extinguished or the gas flow is interrupted.
- Made of high-temperature, heat-resistant ceramic or cement in a variety of finishes.
- Placed directly on the fire grate or lays on a flame pan covered with a bed of volcanic granules for a more realistic looking fire.
- Requires no electricity to operate.
- Fits into fireplaces with a gas hookup and can be installed into any UL-listed, solid fuel burning fireplace or in an
- American Gas Association (AGA) design-certified, vent-free fireplace listed for use.
Vented Gas Log
- Vented gas logs require a venting system and a smoke dome or chimney, installed on the roof.
- Operate at a range of 60,000 to 90,000 BTUs and lose heat as they require the chimney damper to be open.
- Made of high-temperature, heat-resistant ceramic or cement in a variety of finishes.
- Place directly on the fire grate or lay on a flame pan covered with a bed of volcanic granules for a more realistic looking fire.
- Requires no electricity to operate.
- Fits into fireplaces with a gas hookup and can be installed into any UL-listed, solid fuel burning fireplace.
- Gas fireplaces use natural or liquid propane (LP) gas.
- Burns either natural or LP gas to provide primary or secondary heat to a home.
- Conventional models require a venting system and a smoke dome or chimney installed through the roof.
- Newer gas fireplaces can be vented through the wall using a power vent.
- Built-in units require no special flooring or hearth front.
- Can be converted to a wood-burning fireplace.
- Wood fireplaces burn seasoned wood or manufactured wood logs to provide primary or secondary heat to a home.
- Newer prefabricated fireplaces are more energy efficient than traditional masonry ones.
- Must use a venting system. In a conventional, open-face fireplace, the chimney serves as the vent. The drawback is that it pulls warm air up the chimney and out of the house.
- A prefabricated fireplace has an enclosed firebox made of a material that will hold some of the heat from the flue gases so more heat is radiated back into the room.
- Fireplace systems will incorporate a damper in the flue, which can be closed when the fire is extinguished. Otherwise, the warm air will continue to flow out of the house through the draft that is created.
Say you have a wood stove. You have to paint that thing (with stove paint, safe to 1200 degrees Fahrenheit), clean it (with chimney cleaner), fill it (with pellets, wood, children who wander into your enchanted forest). Wait, that’s Hansel and Gretel. But still, you’ve got a lot of tending and keeping to do if you want to keep your stove working well. We haven’t even gotten to AC upkeep. If you have questions, just refer them upwards. This HVAC glossary is for you.