On average, HVAC systems use 39 percent of the energy in commercial buildings, so of course you would like to reduce the energy consumption. There are a couple ways to ensure you are saving as much money as you can on your energy bill. But first, it is important to know about efficiency ratings.
What are the Different Energy Ratings?
There are a few different things you can look for when it comes to HVAC system energy rating. There is the EPA awarded Energy Star, the SEER Rating, and the Department of Energy’s Efficiency Rating.
Energy Star
Energy efficient HVAC systems are awarded the Energy Star by the EPA. To receive the Energy Star, the unit must save a set amount of money on bills. A company will voluntarily submit a unit to get tested and approved.
SEER
The Seasonal Energy Efficiency Ratio, SEER, is an efficiency rating for air conditioning systems. The SEER rating increases as energy and money are saved. Also, the Heating Seasonal Performance Factor is a similar system that measures the heating efficiency of heat pumps.
Department of Energy Efficiency Rating
The Department of Energy regulates all cooling and heating systems in the United States. Every system is given an Efficiency Rating using the Annual Fuel Utilization Efficiency Ratio, or AFUE. The AFUE measures the amount of heat produced for each dollar of fuel that is used. The higher the Energy Efficiency rating, the lower the cost. One more razating for heating efficiency is the Heating Seasonal Performance Factor, or HSPF.
What Systems are Good for Efficiency?
High performance HVAC systems can conserve energy while simultaneously improving the Indoor Environment Quality (IEQ). This means that the indoor air will be comfortable. High performance units can reduce annual energy costs by up to 30% if used with efficient building design over a period of 3 to 5 years. The longer an energy efficient HVAC system is in use, the more energy and money you will save. It is also vital that you have the correct size HVAC system for the building or building area.
The design of the building is also important for saving energy. The design can reduce the need to excessive energy consumption with sun control, shading, and other passive heating and cooling measures.
Why is HVAC Maintenance Important?
Regular HVAC system maintenance can do wonders for the energy consumption, yet few business owners actually perform sufficient maintenance. Properly maintaining your HVAC system could even slash the energy costs in half. It can also extend the life of the system which means more time until you have to buy a new one.
The New Buildings Institute is a nonprofit that works to improve the energy performance of commercial buildings. They found that sufficient maintenance and operation can reduce energy use up to 20 percent in any region of the U.S. Conversely, poor maintenance could cause the HVAC system to consume up to 60 percent more energy. Other studies suggest similar savings. For example, The National Center for Energy Management and Building Technologies found that regularly scheduled maintenance could reduce the cost of the energy bill by up to 20 percent in commercial buildings.
Types of Maintenance
There are three categories of maintenance: reactive, preventative, and predictive. All of them are important, but preventive and predictive can help you avoid reactive maintenance.
Reactive maintenance is used by the majority of businesses. This maintenance occurs when the HVAC system runs into a problem and doesn’t do much to regularly save energy.
Preventive maintenance is scheduled maintenance used by nearly a third of businesses. Periodically scheduled maintenance is a great way to keep your HVAC system running smoothly and efficiently. The schedule is often recommended by the manufacturer.
Predictive maintenance is the most uncommon type, but can save you money, especially when you look at long-term costs. This is because the upfront costs may seem expensive. This strategy maintains the system relative to the condition instead of on a set schedule.
What Causes Decreased Efficiency?
It is good for any owner of commercial property to know what things cause a system to lose efficiency as well as the repairs required.
Dirty Tubes
When microbes contaminate the chiller tube, the heat transfer is impacted. The heat transfer can be reduced even more by deposits of scale or iron. The system has to use more energy to make up this loss in heat transfer. Treating the water and cleaning the tubes can save 10 to 35 percent.
Condenser Flow Rate
Closed, clogged, or damaged valves, nozzles, strainers, condenser tubes, or air in the piping can reduce the flow rate of the condenser. You should have a professional check the condenser flow rate once a year and repair as needed. A reduced flow rate can elevate energy consumption.
Inadequate or Excessive Refrigerant
The efficiency of the chillers will decrease if the level of refrigerant is too high or too low. The correct level is given by the manufacturer. Maintaining correct refrigerant levels can save up to 20 percent on your energy costs. The refrigerant charge also needs to be correct in order for the HVAC to perform as efficiently as possible.
Oil Contamination
Oil in the refrigerant can drastically reduce an HVAC system’s efficiency. For every 1 percent of oil in the refrigerant, the efficiency will drop about 2 percent. You can have the refrigerant cleaned. You can also use a purging system that continually cleans the refrigerant.
Compressor Leaks
A leak will negatively affect the air flow which reduces the energy efficiency. You should regularly have the compressor tested for leaks. A leak can reduce efficiency by as much as 14 percent.
Economizer Failure
Adjusting or repairing economizers or frozen dampers can result in 14 to 40 percent energy savings.
Air Flow
Issues with air flow are generally easy to identify and repair. You should have your air flow checked often. Addressing an air flow issue can result in up to 10 percent energy savings.
Thermostat
Thermostat controls should be checked because errors could cause continuous operation of the fans or other issues that can consume a large amount of energy.
Sensor
Failed sensors can severely reduce the energy efficiency of an HVAC system. It is important to repair them as soon as possible to save a bundle on energy costs. You should also be aware of any snap discs that are unable to be calibrated and broken wiring.
Final Thoughts on HVAC Systems and Saving Energy
To save energy and money, it is important to regularly maintain your HVAC system. Also, when it is time to replace the system, it is a good idea for commercial property owners to check the energy rating and efficiency in order to save the most energy in the long run.
