• Impact on end users


#### **4.4 Energy efficiency ratio assumptions**

By using compliance standard EER values at each specific year along with expected EER values at T1 in future years and utilizing the shares of the weighted average tonnage of small air conditioning units, it was found that the aggregated EER at T1 are as shown below:


In order to be conservative and not exaggerate with energy savings estimates, EER values beyond year 2022 were fixed at year 2022 levels. Hence, the aggregated EER values became as follows:


However, EER values are specified at T1 levels (i.e., 35 degree Celsius) only. It is known that the outside air temperature varies from 18 degrees Celsius where cooling load is required until extreme temperature levels which could occasionally exceed T3 levels of 46 degree Celsius. For the sake of this study, the analysis will be capped at T3 levels as beyond T3 levels are rarely reached. As an example, the average 15 years bin weather data for Dhahran City shows that only .58 of a day in the year is exceeding the 46 degree Celsius. This can be translated to only less than 0.2% of the years above the T3 level in Dhahran.

Although manufacturers provide EER values of an AC unit at several different outside air temperatures (OATs) including T1 (i.e., 35°C) and T3 (i.e., 46°C), they do not provide the EER value at each and every temperature above T1. Therefore,

the EER value for each temperature point above T1 level needs to be identified first in order to be able to calculate the EER's percent reduction at each temperature value above T1. Hence, a linear regression model was applied for different Al-Zamil air conditioning window and split units with diverse EER values at T1. Then, the calculated weighted average value was utilized in energy savings calculations. The regression analysis was following the below equation:

$$Y = a + X \times b \tag{6}$$

**5.1 Energy savings**

from the below equations and tables:

*DOI: http://dx.doi.org/10.5772/intechopen.82634*

**Existing EER**

**Existing EER**

**New unit's Kwh**

**New unit's Kwh**

of the AC units is 2.0176,

*• Window*

*• Split*

**57**

**Year New EER**

**Year New EER**

In order to quantify the overall savings of the program, the calculation started with quantifying the saved energy per unit going from a low-level EER to the proposed level at each specific year. Then, the saved energy per unit was multiplied by the replaced stock at that year in order to get the overall yearly savings. This approach was applied for both window and split units as can be comprehended

*Energy Savings Analysis of a Recommended Residential Air Conditioning Incentive Program…*

EER <sup>¼</sup> Desired Output i*:*e*:*cooling load in BTU

Knowing that 1 TR equals 12,000 BTU/h and the weighted average tonnage (TR)

Annual KWh of Air Conditioner <sup>¼</sup> <sup>12</sup> � TR � Average Annual Operating Hours

**Existing unit's Kwh**

**Existing unit's Kwh**

2018 11.70 8.5 5673 7807 2134 287,500 0.61 2019 11.93 8.5 5562 7807 2245 287,500 0.65 2020 12.94 8.5 5130 7807 2677 287,500 0.77 2021 13.20 8.5 5029 7807 2778 287,500 0.8 2022 13.46 8.5 4932 7807 2875 287,500 0.83 2023 13.46 8.5 4932 7807 2875 287,500 0.83 2024 13.46 8.5 4932 7807 2875 287,500 0.83 2025 13.46 8.5 4932 7807 2875 287,500 0.83

2018 9.66 7 6870 9480 2611 431,250 1.13 2019 9.85 7 6736 9480 2745 431,250 1.18 2020 10.51 7 6315 9480 3165 431,250 1.37 2021 10.72 7 6189 9480 3291 431,250 1.42 2022 10.94 7 6068 9480 3412 431,250 1.47 2023 10.94 7 6068 9480 3412 431,250 1.47 2024 10.94 7 6068 9480 3412 431,250 1.47 2025 10.94 7 6068 9480 3412 431,250 1.47

h

EER

**No. of units**

**No. of units**

**Savings per unit**

**Savings per unit**

(8)

**Savings (TWh)**

**Savings (TWh)**

 Required Input ið Þ *:*e*:*electri power in W (7)

where Y is the dependent variable (energy efficiency ratio of the air conditioner), X is the independent variable (outside air temperature), b is the slope of the line, and a is the y-intercept.

After performing the calculations on the different models, it was found that the weighted average EER drop for a given temperature above T1 value is around 2.1% per degree temperature. Thus, new window units' EER values (adjusted by taking into account EER degradation factor) were computed as follows:


Similarly, new split units' EER values (adjusted by taking into account EER degradation factor) were calculated as follows:


Having said that, the units subject to replacement (10 years old or more) are assumed to have the below EER values at T1. In order to be conservative with the calculation, T1 values for old units are used in calculating the corresponding energy consumption without considering the degradation with temperature:

