Operating as an air conditioning company in West Berlin, NJ, we have seen over the past couple years an alarming rise in the cost of energy. It is fairly obvious that families are increasingly pressed today to find ways to make their air conditioning units work more efficiently for them. We need to spend less per degree of cooling.
This can be done in many different ways, both through minor adjustments, through more radical changes, and also by implementing accompanying insulation measures.
In this article we have tried to list these measures in a meaningful way, by categorizing them either as precautionary and maintenance measures, or as major changes.
1. Enhancing AC efficiency through precautionary and maintenance measures
Regular Maintenance: Every AC requires periodic check-ups to ensure it is running optimally, within manufacturer’s specifications and tolerances. Over time, components will wear out and dust will accumulate, reducing the efficiency of a unit. Through regular maintenance checks, HVAC technicians will be able to identify and repair issues, ensuring that the unit operates its peak efficiency and avoiding very costly repairs as long as possible. If you don’t have a maintenance contract on your AC, we recommend that you get one. Lack of proper maintenance is the primary cause for catastrophic AC failures.
Regular sealing of connections: Over time, connections in the AC system (e.g. between the unit and the ductwork) will become loose due to vibrations, the action of heat and cold, and the pressure built in the system. Regularly checking and sealing these connections will help preventing cooled air losses.
Ductwork inspection and sealing: The ducts that distribute cool air throughout the home can develop leaks that will generate significant losses of cooled air, forcing the AC unit to work harder. Regular inspection and sealing of ductwork helps prevent these losses and improve efficiency.
Fan settings: Using the fan setting on "auto" instead of "on" ensures the fan only runs when the AC is cooling. This reduces energy consumption.
Cleaning and replacing filters: AC filters ensure clean airflow. When they are clogged, the flow is restricted, forcing the AC unit to work harder to achieve the temperature desired, and therefore consume more energy. Cleaning and replacing these filters at regular intervals will help prevent this, lowering energy consumption.
Leaving ventilation returns unencumbered: Vent returns are designed to bring the certain volume of indoor air into the cooling/heating system. The vent openings can be blocked by furniture and various objects, constricting the airflow further, with the same effect as clogged filters. Check that yours are not blocked.
Thermostat calibration: A thermostat incorrectly calibrated will waste energy. Regular calibration ensures that the AC operates more efficiently to achieve the right temperature.
Setting higher or lower target temperatures: In summer, cooling down your home to 75° F instead of 72° F will decrease your utility bill. In winter, heating up your home to 77° F instead of 80° F will also decrease your energy bill. You may not be immediately comfortable reducing the top and bottom limits of your usual comfortable temperature range, but if you progressively increase your lower limit a degree at a time (from 72 to 73 to 74 to 75) over a period of time, and decrease your upper limit in the same way (from 80 to 79 to 78 to 77) you will see your energy consumption diminish.
Optimal refrigerant levels: Refrigerants are what make the cooling in an AC possible. If your refrigerant level drops below the recommended amount, your AC unit has to work harder to achieve the desired cooling, with a corresponding increase in your energy consumption. Regular maintenance will ensure refrigerant levels are maintained at the optimal levels.
Evap coil cleaning: The evaporative coil plays a pivotal role in the cooling process. As warm air passes over this coil, the refrigerant inside absorbs the heat, resulting in cooler air being circulated back into the home. Over time, dust, dirt, and other debris can accumulate on the coil, reducing its heat-absorbing capacity. Cleaning the evaporative coil will significantly improve the heat transfer process. A study from the U.S. Environmental Protection Agency suggests that regular maintenance, including coil cleaning, can enhance AC efficiency by up to 16%.
2. Enhancing AC efficiency through major changes
Using UV filters: Installing UV filters in the AC system prevents the growth of mold and bacteria on the coils. This not only improves air quality but also help the coils function more efficiently.
Higher SEER rating: The SEER (Seasonal Energy Efficiency Ratio) rating is a measure of efficiency of an air conditioning unit. Older units, especially those with SEER ratings below 16, are less efficient. They use more energy to produce the desired temperature. Moreover, the efficiency of an AC unit degrades over time. The rule of thumb in the HVAC industry is a unit loses 0.5 to 1.0 SEER each year. So, a unit with an original SEER rating of 16 might operate more like a 12 SEER unit after a decade. When energy prices rise like it is the case these days, changing your AC system for a new, much more efficient unit starts making a lot of sense
AC zoning systems: In homes with multiple levels or large floor plans, it is preferable to install an air conditioning system based on a zoning system. A zone system allows different areas (or zones) of the home to be cooled to different temperatures, ensuring efficient use of the AC. In a large home, some rooms may be mostly in the shade of trees, or more protected from the sun. Using AC to cool them off make little sense.
Variable speed compressor technology: Traditional AC units have single-speed compressors that operate either at full capacity or turn off. The constant start-stop of a single speed compressor requires a lot of energy. Variable speed compressors automatically adjust their speed based on the cooling demand, leading to a more efficient operation.
Proper sizing of your AC unit: An oversized AC unit can lead to “short cycling”, where the unit frequently turns on and off, consuming more energy. Conversely, an undersized unit will run continuously, trying to meet the cooling demand. Ensuring the AC unit is correctly sized for the space it needs to cool is crucial for optimal efficiency. When you see your AC constantly working to meet your desired temperature, it is worth calling an AC repair technician to determine if your unit is oversized or undersized. At some point, changing it may start making sense.
Installing Energy Recovery Ventilators (ERVs): ERVs exchange stale indoor air with fresh outdoor air. In the process, they pre-cool the incoming air and reduce the cooling load on your AC.
3. Improving your AC energy efficiency through other indoor measures
Proper home insulation is a game-changer in terms of energy efficiency. By insulating roofs, attics, windows, and points of entry, you can prevent the external heat or cold from seeping in. This means your AC doesn't have to work as hard, and this generates significant energy savings.
Research has shown that homes with proper insulation can save up to 20% on heating and cooling costs. We will discuss here various measures you can take to insulate your home better. In a number of cases, the federal or state government will even give you tax credits for implementing these measures.
Points of entry (doors) insulation: Doors are common culprits for air leaks. Weather stripping and sealing gaps prevents cool air from escaping and hot air from entering. Weather stripping is easy and affordable. This is an expense worth incurring.
Windows Insulation: Windows play a crucial role in maintaining indoor temperatures. Double or triple-pane windows with low U-Factor and SHGC (Solar Heat Gain Coefficient) ratings will significantly reduce heat transfer. Additionally, window frames made of vinyl or fiberglass offer better insulation than aluminum because metal is a better conductor of heat than plastic and fiberglass.
Proper sealing and the use of thermal curtains can further enhance home energy efficiency. Sunlight streaming in through windows will significantly increase indoor temperatures. Blinds will reduce heat transfers both ways. Energy-efficient window treatments like reflective films, cellular shades, and blackout curtains also greatly reduce heat transfer between indoor and outdoor. A study conducted in 2015 found that homes with energy-efficient window treatments consumed up to 15% less energy for cooling.
Attic & roof insulation: Your attic and your roof are primary areas where heat can penetrate a home. Using radiant barriers, reflective shingles, and insulating under-decks will prevent heat absorption.
Crawl space insulation: Crawl spaces are a source of moisture and heat. Insulating crawl spaces and ensuring proper dehumidification will reduce the loss of heat or the loss of cool due to these issues.
Effective ventilation: Proper ventilation helps maintain indoor temperatures. When hot air is efficiently expelled and replaced with cooler air, the load on the AC unit decreases. This can be achieved through techniques like cross-ventilation, where windows or vents are placed opposite each other to allow for the free flow of air. Using exhaust fans in areas like kitchens prevents heat build-up. Research has shown that homes with effective ventilation strategies can reduce their cooling costs by up to 30%.
AC ducts efficiency: Ducts transport cooled air from the AC unit to various parts of your home. Leaky or poorly insulated ducts generate significant energy losses. According to the Department of Energy, sealing and insulating ducts can improve the efficiency of heating and cooling systems by up to 20%.
4. Improving your AC energy efficiency through outdoor measures
Green roofs: Green roofs are roofs covered with vegetation. Vegetation acts as insulator, reducing the amount of heat entering your home through your roof. However, you need a roof engineer to determine the structural integrity and load-bearing capacity of your roof. A study conducted in 2017 found that homes with green roofs had indoor temperatures that were 5-6° F cooler than those without.
Renewable energy sources: Modern solar panels can produce between 100 and 415 watts of energy. To run an air conditioner, you would need thirty 100-watt solar panels or ten 300-watt panels. Solar makes sense in certain parts of the country. In New Jersey, unfortunately, it can only be used as a supplementary source of energy, and needs to be coupled with a battery.
Strategic landscaping: Planting trees and shrubs will provide natural insulation from the sun if done right. This type of landscaping is a long term, strategic measure. It takes 8 to 25 years for tree to grow to a roof line, so plant early.