TERMS
WHAT THE
RATINGS MEAN
WHAT IS EER, COP & SEER/SCOP?
EER, SEER, COP, SCOP
The efficiency of a unit is very important as that is is the factor that lets you know how much the system will cost to operate. With all methods of measuring — the higher the number, the more efficient and the less it will cost to operate.
ENERGY EFFICIENCY RATIO (EER)
EER is commonly used in the U.S.A. where units are measured in BTU. EER is
expressed as a ratio of energy output per hour to energy consumption. It is derived by dividing capacity by power consumption. For example, if an air conditioner has a cooling capacity of 6,800 BTU and a rated power consumption of .5 kW, it would have an EER of 13.6.
COEFFICIENT OF PERFORMANCE (COP)
COP is a measure of energy efficiency that compares the amount of power consumed in watts to the amount of power measured in watts that the system puts out. For example, if an air conditioner has a heating capacity of 2kW and a rated power consumption of .5kW, it would have a COP of 4.
SEASONAL EFFICIENCIES
The SEER (Seasonal Energy Efficiency Ratio) and SCOP (Seasonal Coefficient
of Performance) function similar to their counterparts except that the measurements are taken over the span of a year. This method accounts for regional climatic conditions and allows efficiency to be measured throughout all four seasons. For example, the SEER for an air conditioner in Europe would be different to that for the same air conditioner in the Israel.
MEASURING
POWER
WHAT IS A BTU, KW OR HP?
BTU, KW, TONS AND HP
All air conditioners are rated based on their capacity to cool. There are different methods employed to measure this output. Cooling capacity is the measure of a cooling system’s ability to remove heat.
KW
Based on the International System of Units, a watt is a measure of energy flow used to express the cooling capacity, heating capacity and power consumption of an air conditioning system. Each KW is equivalent to 3,412 BTu/H.
BTU
The acronym stands for British Thermal Unit, which is the unit used to measure thermal (heat) energy. Specifically, it is the amount of energy needed to raise one pound of water 1°F at sea level. When used in relation to air conditioning systems or heaters, the measurement is expressed in terms of how many BTUs per hour the product can add or remove from the air. This is expressed as BTu/H.
HP (כוח סוס OR כ“ס)
This is commonly used in Israel, however, it is being phased out in favor of the more universal KW or BTu/H. The acronym stands for כוח סוס , Horse Power (HP). One כוח סוס is equal to 9,000 BTU or 2.6 KW.
TON
A ton of refrigeration is the ability of a refrigerator to freeze 2,000 lbs of water at 0°C or 32°F in the period of 24 hours. One ton of refrigeration is equivalent to 12,000 Btu/H or approximately 3.5 KW.
COMPARISON TABLE
We’ll use this for a typical bedroom to demonstrate the differences:
WHAT IS A HEAT PUMP?
In many parts of Israel homes use the same system for cooling and heating, this uses heat pump technology.
Imagine that you took an air conditioner and flipped it around so that the hot coils were on the inside and the cold coils were on the outside. In that case, you would have a heater. It turns out that this heater works extremely well, and costs a fraction of running an electrical heater (it’s also a lot safer). A heat pump is an air conditioner that contains a valve that lets it switch between “air conditioner” and “heater.” When the valve is switched one way, the heat pump acts like an air conditioner, and when it is switched the other way, it reverses the flow of the liquid inside the heat pump and acts like a heater.
