HVAC efficiency refers to how efficiently your system converts energy into the cooling, heating, and ventilation you require. The more efficient your system is, the cheaper it is to run. There’s also the matter of environmental impact. HVAC is the number one contributor to the average American household’s carbon footprint. Let’s explore 13 factors that shape your system’s efficiency.
1. Efficiency Ratings
There are three core energy efficiency ratings that the Department of Energy (DOE) uses to set standards for the American consumer. In all cases, the higher the number, the more efficient the system.
Annual fuel utilization efficiency (AFUE) indicates how much fuel a furnace or boiler wastes in the conversion process. An AFUE 81 furnace wastes 19% of the fuel it converts into heat energy.
Seasonal energy efficiency ratio (SEER) measures cooling efficiency over an entire cooling season. You can use SEER not only to compare air conditioners but also heat pumps in cooling mode.
Heating seasonal performance (HSPF) is like SEER but measures heating efficiency. This is necessary for heat pumps, which transfer heat energy rather than generating heat as a furnace does.
2. Climate
In general, extreme temperatures will negatively impact HVAC efficiency. This is why the DOE sets the minimums for energy efficiency by region rather than nationwide. It’s also why northern homeowners have been slower to adopt air-source heat pumps, which run less efficiently in very cold temperatures.
3. Building Envelope
The building envelope of your home refers to its seal. A home with a tight seal will be very efficient. Homes with loose seals will waste more heating and air conditioning. Aspects that make up a building envelope include the roof, doors, windows, insulation, foundation, and so forth. One way to assess your building envelope is to schedule a home energy audit. You can then use this information to target the aspects of your home that are undermining HVAC efficiency.
4. Sizing
Size in the HVAC world refers to the overall capacity of the system. You neither want an undersized nor oversized HVAC system. The goal is to get it just right. An incorrectly sized system will cycle too frequently or for too long a period. That will drive up your operating costs. It will also increase wear and tear, which will make repairs more common and decrease the equipment life span. This is one reason why it is so important to hire a professional installer who will perform a load calculation for your home.
5. Thermostat
A thermostat is integral to efficiency because it reads the temperature in the home and dictates the heating and cooling cycles. It’s important to have a thermostat that’s centrally located and that has an accurate temperature sensor.
Programmable and smart thermostats can make your system even more efficient. Both types allow for scheduling that lets you save while you’re sleeping or away from home. Smart models add energy-saving features like energy monitoring, geofencing, and smart setback.
6. Humidity Control
Relative humidity (RH) reflects the amount of water vapor in the air within the context of temperature. In high humidity, your AC will be less efficient, and you’ll need a lower temperature to feel comfortable. You can improve cooling efficiency with a dehumidifier that lowers RH during summer. You can also improve heating efficiency with a humidifier that raises RH during winter.
7. Installation
Proper sizing is just one aspect of HVAC efficiency and why it’s so important to hire an experienced HVAC installer. Others include equipment placement, static air pressure, and adhering to the manufacturer’s specifications for the installation.
8. Maintenance
HVAC warranties typically require seasonal maintenance as a condition for coverage. Schedule in spring for your cooling system. Schedule again in fall for your heating system. This is good advice even if you have a heat pump that both cools and heats. Equipment gets dirty over time and becomes less efficient. It’s also necessary to tighten electrical connections, lubricate moving parts, and so on.
9. Static Air Pressure
Static air pressure is an important concept in HVAC performance. It refers to the resistance to airflow in the ducts. The blower is on the other end of the system moving the air. If air pressure is too high or too low, it will affect comfort throughout the entire home. It will also make the system work harder, which will decrease energy efficiency and increase your operating and long-term costs.
The main cause of static air pressure issues is a clogged HVAC filter. This is why you should check your filter at least every month and replace it as needed. During a seasonal tune-up, your technician will service your blower or air handler and check the static air pressure.
10. System Age
HVAC systems become less efficient with age. Routine maintenance and preventative repairs will slow the decline, but some deterioration is inevitable. There’s also the fact that new models are becoming more efficient each year. This is why it’s rarely economical to wait for an HVAC system to fail before replacing it. In fact, the DOE estimates that homes with older systems can save 20% or more annually with an upgrade.
11. Air Leakage
Air leakage refers to heating and cooling that seeps out of the seals in your ducts. The DOE estimates that air leakage causes heating and cooling losses of between 20% and 40%. To avoid this, schedule a yearly video camera inspection of your ducts. When the seals wear out, you can have the ducts resealed, which can lower your losses to 5% or less.
12. Zoning
Traditional central HVAC systems have a single zone, which is the entire home. A multi-zone system is a modern option through which we organize the home into multiple discrete zones. This requires additional equipment, such as a variable-speed blower and active duct dampers. Zoning makes an HVAC system more efficient because it allows you to adjust the temperature in each zone. You can, for instance, increase the AC in the zones you’re using and turn it down in those you’re not.
13. Air Balancing
In a balanced HVAC system, each vent or vent group is providing the right airflow for that particular room or area. With a traditional single-zone system, you generally only need air balancing performed during an installation or replacement. Zoned systems are more complex and sensitive. Experts recommend balancing every several years or so. An imbalanced zoned system will be less comfortable and cost more.
Would You Like to Improve Your HVAC Efficiency?
Beltway Air Conditioning, Heating, & Plumbing serves homeowners and businesses throughout Arbutus, Columbia, Hanover, Pasadena, Severn, and the surrounding areas. Our licensed technicians specialize in HVAC efficiency. We install, maintain and repair furnaces, boilers, heat pumps, air conditioners, and ductless mini-splits. Our team installs and calibrates thermostats, installs and repairs ductwork, and performs oil-to-gas conversions. We have an indoor air quality team that cleans ducts and installs air purifiers, humidifiers, and carbon monoxide detectors. Our company also has licensed plumbers who perform inspections, repairs, and installations. They fix leaks and clean clogs. You can also count on us for water heaters, sump pumps, water softeners, dishwashers, sewer lines, well systems, and much more. Call today or contact us online to ask questions or to schedule a consultation or service appointment.
