The basic components of any air conditioner include a compressor, condenser coils, refrigerant, and a motorized fan. These components work together to cool a space by drawing heat from the indoor air and releasing it outdoors.
First, refrigerant enters the compressor as a cool gas. There, it is pressurized until it becomes very hot. The refrigerant then moves through condenser coils that release the heat into the outdoor air, changing the refrigerant into a cool liquid in the process. Next, the liquid refrigerant is forced through a tiny expansion valve followed by another series of coils, where it begins to evaporate, drawing heat out of the surrounding air. A motorized fan helps distribute this cooler air.
Finally, the cooled refrigerant re-enters the compressor as a gas, ready to start the process all over again. A thermostat will monitor the indoor temperature and shut off the compressor when the desired temperature is met, or restart the compressor when it detects that the room has become too warm.
Ideal for milder climates, a heat pump is an outdoor unit that can provide efficient heating and cooling. On colder days, the unit draws heat from outdoor air and circulates it indoors. In warmer seasons, the process reverses and the unit removes heat from indoor air and releases it outdoors. This means a heat pump can provide money-saving energy efficiency all year round.
Unlike a traditional single-stage motor, which can only operate at one speed, a variable speed motor slowly ramps up or down over a wide range of speeds. This not only provides more precise temperature control, but also quieter operation, since it eliminates the noisy startups sounds associated with single-stage motors.
Variable speed motors are also highly efficient. Rather than working at full capacity to heat or cool a space, they automatically adjust to the appropriate speed. This means increased energy efficiency as well as utility savings, since variable speed motors use less electricity compared to standard single-stage motors.
With two-stage heating or cooling, your air conditioner, heat pump or furnace can operate at two different settings to deliver more precise temperature control and greater efficiency than a standard single-stage unit.
Here’s how it works: most of the time, the unit works at low capacity to meet heating or cooling demands. But on extremely hot or cold days, it automatically switches to the higher setting to keep the temperature consistent. When the desired temperature is reached, the unit will then switch back to the first stage. Since the unit operates in the lower setting most of the time, it can provide efficient heating and cooling that can significantly reduce utility bills. Two-stage operation is also quieter than its single-stage counterpart, since it’s not constantly working at full blast.
A zoning system creates separate temperature zones throughout a building to provide greater control and energy efficiency. Dampers located in the ductwork help direct airflow to each zone, which is connected to its own programmable thermostat.
This allows you to meet specific temperature requirements throughout the building, without affecting other areas. Perhaps there’s a space that’s not currently being used, or maybe you have a room with large computer equipment that gets too hot. With zoning you can control each specific space and reduce utility costs since you’re not paying to heat or cool areas not in use.
Different HVAC equipment requires different measurements to indicate energy efficiency. Here are the most common ratings and what they mean.
- AFUE (Annual Fuel Utilization Efficiency) – Used to measure a furnace’s heating efficiency, AFUE is a ratio of the usable heat put off by a furnace compared to the amount of energy consumed in the process. The higher the AFUE, the less heat and fuel a furnace will waste during daily operation, and the less it will cost per season to use.
- HSPF (Heating Season Performance Factor) – Used to measure the efficiency of heat pumps, HSPF is the ratio between heat energy supplied to a building during a typical heating season compared to the amount of electricity consumed. The higher the HSPF, the less electricity is needed to deliver a set amount of heat.
- IEER (Integrated Energy Efficiency Ratio) – Used to indicate the part-load efficiency of commercial air-conditioning equipment based on weighted operation at various load capacities.
- SEER (Seasonal Energy Efficiency Ratio) – Used to rate the energy efficiency of air conditioners, SEER is the ratio between the amount of cooling output a unit produces during a typical cooling season divided by the total amount of electricity it consumes while doing so. The higher the SEER, the more cooling is produced per watt hour of electricity, and the lower HVAC costs become during the summer.
ENERGY STAR® designates a heating or cooling unit that meets or exceeds efficiency standards set by the U.S. Environmental Protection Agency. The higher the operating efficiency of your equipment, the more energy you’ll conserve and the greater the potential for utility savings.
Heating and cooling can account for up to 50% of a building's energy use.* With a high-efficiency HVAC system from Allied Commercial, you can significantly reduce energy consumption and utility costs. Installing energy-efficient equipment may also qualify for federal tax credits and local utility rebates.
Look for these other features on Allied equipment to help further reduce operational costs.
- Easy installation – Construction details, such as hinged access panels, make units easier to install and access, saving maintenance time and money. Features such as high- and low-pressure switches can protect compressors from unnecessary wear and reduce maintenance expenses.
- Demand Control Ventilation (DCV) –Unlike many HVAC systems that provide ventilation based on assumed occupancy, Allied’s DCV systems include carbon dioxide sensors that can accurately read a room's occupancy level. This means the system is always producing the proper amount of ventilation, without wasting energy.
- Economizers – Integral economizers can detect when the weather is cool and dry and automatically use the outdoor air for cooling, rather than operating the compressors. This not only reduces energy costs but also saves wear and tear on the compressors.
- Building Automation Systems – Using a single interface to control multiple rooftop units can save time, increase control and reduce energy use. Plus, many central control systems include technologies such as remote monitoring and advanced diagnostics that can help keep energy use and maintenance expenses to a minimum.
- Planned Replacement – Older HVAC equipment not only requires more frequent (and often more expensive) repairs, but also decreases operational efficiency due to unexpected downtime. By replacing HVAC equipment before it becomes an emergency situation, you’ll benefit from newer, more efficient equipment as well as the ability to control the timing of capital expenditures.
Short for Leadership in Energy and Environmental Design, LEED is a system of ratings created as guidelines for the construction, design and daily operation of environmentally friendly “green” buildings.
LEED certification is based on 100 points distributed across five categories: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources and Indoor Environmental Quality. There are four levels of LEED certification based on the number of points a building earns.
CERTIFIED: 40 to 49 points
SILVER: 50 to 59 points
GOLD: 60 to 79 points
PLATINUM: 80 or more points
Buildings that are LEED certified will use energy more efficiently than standard buildings, and as a result often enjoy tax savings or other incentives for their smart energy use. Typically, the higher their LEED certification, the more incentives they receive.
LEED certification for all commercial and institutional projects is administered by the Green Building Certification Institute (GBCI).
For more information on the certification process, visit the GBCI website.
No. LEED credits are earned by meeting performance standards rather than by using particular products. Each project team is free to determine which products and services will help their building meet those performance requirements.
For many years, R22 was the standard refrigerant used in air conditioners. However, the U.S. Environmental Protection Agency (EPA) is now phasing out its use. R410A is an environmentally friendly, chlorine-free refrigerant that meets the latest EPA guidelines.