ESEER is one of the most accurate metrics to determine **air conditioner energy efficiency**, At HVAC, we already have a lot of these ratings; You may be familiar with EER and SEER ratings, some may have even heard of CEER and IEER ratings.

*Example:* A portable air conditioner can have an EER rating of 11.0, a SEER rating of 14.3, an IEER rating of 15.6 and an ESEER rating of 15.4. It is quite confusing to have such a high energy efficiency rating.

So we will look at what ESSER is and why it could become a major energy efficiency ratio in Europe.

**ESEER** stands for * Ieuropean seasy Ienergy Iefficiency Rvery*, It is used to estimate adequately

*actual climate*Energy efficiency of air conditioning units. Here’s how the ESEER rating is calculated (we’ll look at this equation later):

Now, there is a lot of confusion about what is ESEER and how it is measured/calculated. Let’s clear a few things:

most of us know what **EER** Or means Energy Efficiency Ratio (this is the ratio between the AC unit’s cooling output at 100% power input or wattage, more about EER rating here). **seer** Or is the seasonal energy efficiency ratio a step ahead; We measure EER rating at partial load *(EER) _{25%}EER_{50%}and EER_{75%},* and at full load

*(EER)*And calculate SEER rating using weighted average.

_{100%},If you compare ESEER with EER and SEER ratings, you might think that ESEER is simply the European version of SEER rating. This is one of the most common mistakes that most of us make.

Yes, ESEER is a European rating. was introduced in **April 2006 in Frankfurt** and presented in the paper by Eurovent Certification Company Title *“Impact of Certification on Chillers Energy Efficiency”*,

But ESEER is not the only European version of SEER that is more commonly used in the US. ESEER, in fact, makes a more thorough estimate of energy efficiency because it integrates both **partial load** As well as **different test conditions** (namely, eSer is measured at 35 °C, 30 °C, 25 °C and 20 °C). In that respect, it is closer to the IEER or the Integrated Energy Efficiency Ratio used in the US.

Here’s the typical deal:

All of these AC energy efficiency ratings seek to estimate how energy efficient an air conditioner really is under actual climatic conditions. ** actual climate Conditions** Here are the keys. We would really like to know how much does a fixed air conditioner cost to run.

To fully understand the meaning of ESEER rating, we need to look at how it is calculated:

## How to Calculate ESEER Rating (Part Load + Various Test Conditions)

EER rating is calculated only on **only 1 ideal situation** and at 100% capacity. We assign this rating to EER . denote as_{100%}, The SEER rating still uses that 1 ideal condition but takes into account the load at 25%, 50% and 75% in addition to the 100% load.

However, when calculating the ESEER rating, we include two very important factors:

**different loads**(similar to SEER rating). these are loaded**25%, 50%, 75% and 100%**Air conditioner cooling capacity.(Not just ideal 35°C outdoor temperature conditions). To measure ESEER, we measure that there are 4 different conditioners. Namely, we not only measure the performance of an air conditioner*different test conditions***35°C, but 30°C, 25°C and 20°C. but even**,

This mix of different loads and different test conditions on which the ESEER rating is based is important. This is the best way to truly evaluate the real life energy efficiency of an air conditioner.

Here is the formula to calculate ESEER rating:

**ESEER = (EER.) _{100%} × 0.03) + (Eer.)_{75%} × 0.33) + (Eer.)_{50%} × 0.41) + (EEER.)_{25%} × 0.23)**

This is how all 4 components of the ESEER rating are measured and how much of each of them is input into the total ESEER rating:

- EER
_{100%}100% cooling output and measured at 35°C. This is 3% of the total ESEER rating. - EER
_{75%}75% cooling output and measured at 30°C. It accounts for 33% of the total ESEER rating. - EER
_{50%}50% cooling output and measured at 25°C. It accounts for 41% of the total ESEER rating. - EER
_{25%}25% cooling output and measured at 20°C. It accounts for 25% of the total ESEER rating.

The ESEER equation is a basic weighted average of these different measurements.

Basically, to best capture real-life conditions as possible, the ESEER rating assumes that we run the air conditioner at 50% capacity at most, followed by 75% and 25%. It is also assumed that we run the air conditioner at 100% capacity only 3% of the time.

*How does this ESEER rating compare to EER and SEER ratings?*

### Converting ESEER to EER and SEER (Is it even possible?)

Whenever we are looking at EER vs ESEER or SEER vs ESEER rating, we want to get a general idea of how energy efficient this 15 ESEER rated air conditioner is.

That means we want to convert **ESEER to EER** or to convert **ESEER to SEER** Because we are more familiar with EER and SEER.

However, it is important to understand that ** Impossible** To convert ESEER rating to EER or SEER directly.

This is because EER and SEER are measured in only 1 ideal position. In contrast, ESEER is measured at 4 different test conditions (35°C, 30°C, 25°C, 20°C). Comparing EER or SEER with ESEER is like comparing apples and oranges.

This means that the ESEER rating is a stand-alone energy efficiency metric for the air conditioner. We have to make a habit of comparing different air conditioners based on ESEER. *Or is this also the case?*

The IEER rating is equal to the ESEER rating. The IEER is slowly but steadily replacing the old EER rating and even the new SEER rating.

However, we do not see ESEER equally replacing EER and SEER in Europe.

Only time will tell which AC energy efficiency metric we’re going to use primarily in the future. Despite ESEER being the most complete and accurate metric for real-climate energy efficiency of AC units, it does not currently actually appear on the specification sheets of modern air conditioners.

Hopefully, you now have a better understanding of what the ESSER rating means and the extent to which it estimates the energy efficiency of various air conditioning systems.

,