One of the common factors that people have considered in the past when choosing an HVAC system is the Energy Efficiency Ratio – otherwise known as EER. Today, there are newer standards being used, including EER2 which is playing a significant role in changing how performance is measured. It’s impacting how consumers are making their choice as well.
According to the US Energy Information Administration, over half of the energy used in a household is for heating and air conditioning. This is of course influenced by the climate and the type of home, as well as number of household members as well as other factors. So understanding how efficient a unit is, and how that efficiency is measured, is paramount. At Daikin, we have over a century of experience in heating and cooling systems, and in this article we will break down everything you need to know about EER2 so homeowners and businesses can make better decisions about what to purchase.
What does EER2 mean in HVAC?
EER2 is a metric that measures how efficiently an HVAC system converts electrical energy into cooling output. It gives you information on how many units of cooling are produced for each watt of electricity consumed. So the higher the EER2, the more energy-efficient the system is.
EER2 is a replacement for the older EER standard. It offers a more accurate testing procedure which reflects operating conditions in the real world. While both EER and EER2 show the relationship between cooling output and power input, EER2 uses stricter standards which were introduced in 2023. The updated EER2 uses new measurements in external static pressure, fan speeds, and refrigerant types. In this way, it gives a more realistic picture of a system’s performance in daily regular use, rather than a lab experiment type of setting.
How EER2 is calculated
EER2 is calculated by dividing the cooling capacity of an HVAC system by the amount of electrical power it consumes under specific test conditions.
The formula is as follows: EER2 = Cooling Output (BTU per hour) ÷ Power Input (Watts)
Cooling output represents how much heat the system removes from indoor air per hour. The power input measures the total electrical energy consumed by the unit. The testing takes place under standard conditions, usually an outdoor temperature of 35°C, an indoor temperature of 27°C with 50 % humidity, and a higher external static pressure to simulate real duct systems. Because the EER2 tests are more demanding than the older EER tests, the EER2 values do tend to be lower than older EER numbers. Nevertheless, EER2 does offer a more accurate representation of efficiency during peak operation.
EER vs. EER2: What’s the difference?
Let’s now look at the key difference between EER and EER2. The main difference is in how each rating is tested and then how accurately it reflects performance in the real world. The original EER was based on ideal laboratory conditions so there was low external static pressure as well as fixed fan speeds. Because of this, it only gave a theoretical idea of efficiency.
In contrast, EER2 uses updated test methods that simulate real installation conditions. It accounts for a number of things including variable fan speeds, higher external static pressure, as well as duct losses. This is important as these are factors that affect system performance once installed. So EER2 will give a more accurate idea of how an HVAC system will perform under actual load conditions.
In daily use, an EER2 rating gives both homeowners and businesses a much clearer picture of how efficiently their system will operate during hot weather when cooling demand is at its highest. This in turn helps them make more informed decisions about long-term energy use and cost savings.
Why EER2 ratings matter for consumers
EER2 ratings do matter for consumers because without them it’s impossible to get a really clear picture of how an HVAC system will perform under peak conditions. Once you understand the rating, you can select the right unit, ensuring that you are able to achieve improved energy savings. It also means you’re compliant with the latest HVAC standards.
Let’s look at the key benefits in more detail:
Improved energy savings: Because EER2 is measured under much stricter conditions, if you choose a unit with a higher EER2 number then you waste less energy, particularly during very hot days.
Lower operating costs: A more efficient unit means you use fewer kilowatt-hours. That means lower electricity bills which you will really notice if you’re in a region where you need to run the air conditioning for long periods.
Better performance in extreme heat: If you live in a hot climate, the EER2 metric can tell you how your system is performing when it is working at its hardest. After all, this is when you most need reliability and efficiency – when the unit is working hard.
Compliance with new standards: A number of jurisdictions and manufacturers now require (or reference) the M1 test procedure and EER2/SEER2 ratings for eligibility of rebates or subsidies.
Longevity & sustainability: If your system is running efficiently then it’s going to be under far less strain which means your equipment lasts longer as well as having a smaller environmental footprint.
FAQs about EER2 in HVAC
What is considered a good EER2 rating for an air conditioner?
A good EER2 rating depends on your climate and system type, but generally a figure of around 11–12+ for residential split-systems is ideal.
How is EER2 different from SEER2?
EER2 measures efficiency at a single set of peak conditions to indicate full-load performance, while SEER2 (Seasonal Energy Efficiency Ratio 2) measures average efficiency over a wider temperature range across a cooling season. In a region with very extreme heat, EER2 is more indicative of your system’s performance on the toughest days. However, SEER2 may be more suitable if you live in a moderate climate.
Do all new HVAC systems require EER2 certification?
Not all HVAC units installed in the UAE require EER2 and in some cases EER is still in use.
Will EER2-rated systems cost more upfront?
Usually yes. Systems designed to achieve higher EER2 ratings tend to cost more initially due to better components, advanced compressor and fan control, refrigerant design and manufacturing tolerances. The increased upfront cost can be offset over time through lower operating bills and reduced energy consumption.
About Daikin
Daikin stands at the forefront of energy-efficient HVAC innovation, designing advanced systems that meet or exceed the latest EER2 and SEER2 efficiency standards. The company’s commitment to sustainability, performance, and air quality drives every product, from residential air conditioners to large-scale commercial systems. Engineered for long-term reliability, Daikin units deliver cleaner, healthier air with reduced energy consumption.
With a global workforce of more than 100,000 employees and a century of technical expertise, Daikin continues to lead the HVAC industry in developing next-generation, eco-friendly climate solutions.
