HVAC Equipment Basics & Terminology

Know the Ins and Outs of Heating and Cooling Systems Before It’s Time To Buy!

Just like contractors, All heaters and air conditioners are not created equal. When looking for a new heating or air conditioning system, there are several different factors you should consider. The following are some basic equipment terms, components, and facts you should know before you buy a new heating or cooling unit. Simply knowing these equipment basics will save you time and money in the long run.

Gas Heating Systems:

Understanding 80% and 90%-95% Efficiency Units: In an 80% efficient system, gasses are hot enough that they need to vent conventionally into the chimney stack. In a 90%-95% efficient system, the gasses are much cooler and vent to the outside via an exhaust vent, much like a clothes dryer.

• AFUE (Annual Fuel Utilization Efficiency): Indicated as a percentage, your furnace’s AFUE tells you how much energy is being converted to heat. For example, an AFUE of 90 means that 90% of the fuel is being used to warm your home, while the other 10% escapes as exhaust with combustion gasses.
• Combustion Air: Combustion air is the air required to properly burn the gas for your heating system to get maximum capacity.
• Heat Exchanger: This is the part of a furnace that transfers heat to nearby air, the chamber where fossil fuel is burned. An improperly sized heater will cause expansion and contraction of the heat exchanger, which will lead to premature aging and cracks.
• Venting Types: Your new gas heater will vent the combustible gasses in one of two ways – via a direct vent system or into an existing chimney. In most cases, the chimney will need to be relined in order to generate the correct draft.
• Single-Stage Gas Valve: Single Stage Gas Valves operate on a basic on/off principle. Each time your thermostat calls for heat, your heating system comes on at 100% capacity.
• Two-Stage Gas Valves: Two-Stage Gas Valves are capable of two levels of operation — a low stage and a high stage. Properly sized equipment will operate 60-70% of the time in low stages, enhancing energy efficiency and comfort with perfect humidity levels and quieter operation. It’s like getting two heaters in one.
• Standard Blower: A standard blower delivers a specified amount of airflow based on a tap setting.
• Variable-Speed Blower: This high-efficiency blower is designed to deliver a varying amount of airflow based on the desired outcome. These blowers increase the effectiveness of humidification, dehumidification, air filtration, and balance of airflow.
• Humidification: This is the process of adding moisture to the air by using a whole-house humidifier. During the winter months, heated air can make your house too dry. Adding moisture protects your furnishings and reduces static electricity. Coupling a humidifier with a variable-speed blower gives you the ability to manage your humidity to the exact level you would like.
• Indoor Air Quality: This refers to the cleanliness and healthiness of the air in your home. Many factors affect air quality: smoking, pets, location of the property, age of the home, tightness of the house, etc. Perhaps the biggest enemies of indoor air quality are allergens – microscopic particulate matter, bioaerosols, and volatile organic compounds that can produce allergic reactions, impede breathing or make you sick. Dust, pollen, germs, mold, and chemicals – all can be in the air. The wrong heating system can house, spread and recirculate these allergens.

Boiler Systems:

• Indirect Fired Water Heaters: This style of water heater has a longer life expectancy, fewer standby losses, and recovery rates up to 10 times normal coil and water heater rates.
• Components include: Pump Away Process, Isolation of Circulators, Pressure Reducing Valve, Circulators (not Zone Valves), Spiro Vent, Backflow Prevention Valve, and Full Flow Valve.

Chimney Liners:

• Higher Efficiency Furnaces and Your Chimney: Most furnaces installed today have Annual Fuel Utilization Efficiency (AFUE) in the 78% to 81% range. Since these furnaces use more of the heat produced by the furnace to warm your home, there is less heat in the exhaust gasses that are vented outside. When not vented properly, these lower-temperature exhaust gasses could lead to moisture in your chimney.
• Condensation and Chemistry Lead to Corrosion: If you’ve ever enjoyed a glass of iced tea on a hot summer day, you’ve experienced condensation firsthand. Warm moist air comes in contact with the cold surface of the glass and forms water droplets. Something similar could happen in your chimney. Warm moist air hits the cold chimney wall, and water droplets form on the inside of your chimney. Condensation was not a problem with your older, less efficient furnace because more of the heat produced escaped up the chimney, carrying moisture with it. But while today’s furnaces are more efficient, they are prone to condensation buildup, and that can lead to rust and corrosion.
• Why You Need a Chimney Liner:
  • Installing a proper metal chimney liner requires a small cost upfront when compared with the costs to repair a corrosion-damaged chimney in the future.
  • A listed metal chimney liner ensures that your home is up to local and national building codes – an important consideration if you ever decide to sell your home.
  • A metal liner will protect you and your home against the effects of condensation, including chimney damage, ruined drywall, corrosion in your furnace, and backed-up exhaust gasses. F.H. Furr strongly recommends stainless steel liners over aluminum liners. Stainless steel offers far greater strength.

Air Conditioners:

• SEER: SEER (Seasonal Energy Efficiency Ratio) is the measure of efficiency by which the cooling process of air conditioners and heat pumps is rated. The higher the SEER rating, the greater the efficiency – and, therefore greater energy savings.
• Single-Stage Compressor: Single Stage Compressors operate on a basic on/off principle. Each time your thermostat calls for cooling, your air conditioning system comes on at 100% capacity.
• Two-Stage Compressor: Two Stage Compressors are capable of two levels of operation, a low stage and a high stage. Properly sized equipment will operate 80% of the time in a low stage, enhancing efficiency and comfort with lower humidity levels and quieter operation. It’s like getting two air conditioners in one system.
• Refrigerant: R-410a (also known as Puron) is an environmentally-sound refrigerant designed not to harm the earth’s ozone layer. Federal law requires that all manufacturers phase out R-22 (better known as Freon) and other ozone-depleting refrigerants in the next few years. R-410a refrigerant is approved by the US Environmental Protection Agency as a replacement for R-22.
• Dehumidification Mode: The process of varying airflow and compressor operation can allow certain air conditioning applications to manage exact indoor humidity levels.

Heat Pumps:

• HSPF: The Heating Seasonal Performance Factor is a measure of the heating efficiency of a heat pump. The higher the HSPF number, the more efficiently the heat pump heats your home.
• SEER: SEER (Seasonal Energy Efficiency Ratio) is the measure of efficiency by which the cooling process of air conditioners and heat pumps is rated. The higher the SEER rating, the greater the efficiency – and, therefore greater energy savings.
• Refrigerant: R-410a (also known as Puron) is an environmentally-sound refrigerant designed not to harm the earth’s ozone layer. Federal law requires that all manufacturers phase out R-22 (better known as Freon) and other ozone-depleting refrigerants in the next few years. R-410a refrigerant is approved by the US Environmental Protection Agency as a replacement for R-22.
• Standard Blower: A standard blower delivers a specified amount of airflow based on a tap setting.
• Variable-Speed Blower: A high-efficiency blower that is designed to deliver a varying amount of airflow based on the desired outcome. These blowers increase the effectiveness of humidification, dehumidification, air filtration, and balance of airflow.
• Humidification: This is the process of adding moisture to the air by using a whole-house humidifier. During the winter months, heated air can make your house too dry. Adding moisture protects your furnishings and reduces static electricity. Coupling a humidifier with a variable-speed blower gives you the ability to manage your humidity to the exact level you would like.
• Dehumidification Mode: The process of varying airflow and compressor operation can allow certain air conditioning applications to manage exact indoor humidity levels.
• Electric Heat Staging: The ability to bring the electric backup heat in stages as opposed to coming on all at once.
• Indoor Air Quality: This refers to the cleanliness and healthiness of the air in your home. Many factors affect air quality: smoking, pets, location of the property, age of the home, tightness of the house, etc. Perhaps the biggest enemies of indoor air quality are allergens – microscopic particulate matter, bioaerosols, and volatile organic compounds that can produce allergic reactions, impede breathing or make you sick. Dust, pollen, germs, mold, chemicals – all can be in the air. The wrong heating system can house, spread and recirculate these allergens.

Accessories:

• Humidifiers: These products operate by adding moisture to the air by using the blower from the heating system. This adds the necessary moisture to protect your furnishings and reduce static electricity. Coupling a humidifier with a variable-speed blower gives you the ability to manage your humidity to the exact level you would like.
• Air Filtration: Adding a high-efficiency air cleaner can dramatically impact your family’s health. Ask your F.H. Furr consultant which model will benefit you most.
• Hot Water Heaters: Updating your current water heater can benefit you by saving you money on your utility bills and improving the amount of hot water that you have available to you.
• Zoning: Zoning your home’s heating and cooling system gives you the control you need to be comfortable in any part of your home without the worry of changing temperatures in other rooms. While most people zone for comfort, proper zoning allows you to heat or cool only the zones that need it.
• UV Bulbs: Ultraviolet bulbs work by killing mold spores and live airborne bacteria with shortwave light. This technology is used in most hospitals and laboratories to obtain the cleanest air possible.

A Note About Efficiencies and Equipment Size:

When you’re getting ready to replace an older heating or cooling system, it’s very important for you to get a Load Calculation done by your dealer or contractor. This Load Calculation is an estimate of how hard your system will have to work in order to optimally heat and/or cool your house. This calculation includes:

• Inspecting your home from top to bottom, including walls, floors, and ceilings
• Identifying windows, doorways, and room sizes
• Identifying drafts
• Recording insulation
• Meeting building codes and industry standards

From this Load Calculation, your F.H. Furr Comfort Consultant can determine the proper size of equipment for your needs. By running a Load Calculation, your F.H. Furr Comfort Specialist will be able to accurately size the system to the load in your home. In fact, the greater the difference between the efficiency of your old system and the new one, the more likely that your Comfort Specialist will recommend a smaller-sized unit. That’s because units that are too large will perform much less efficiently than smaller ones; they’ll cost you more to operate and are more likely to break down. Generally speaking, under-sizing your heating and cooling equipment will provide the same or greater comfort as installing a larger unit and at a lower operating cost.