Seasonal efficiency measures the true energy efficiency of heating and cooling systems. It gives you a realistic indication of the energy efficiency and environmental impact of your systems. This new method of rating energy efficiency is driven by the EU’s Energy Related Products (ErP) directive, which specifies the minimum eco-design requirements manufacturers must integrate into their energy-using products.
Understanding your seasonal energy efficiency rating (SEER) can also help you save a substantial amount of money. For every kilowatt of power saved each hour, you can save £876 per year, or approximately four tons of CO2, so it’s well worth working it out.
The energy efficiency ratio (EER)
First you must work out energy efficiency ratio (EER), which measures how efficiently your cooling system operates when the outdoor temperature is at a particular level. EER is the ratio of the cooling capacity to the power input of the unit. The higher the EER, the more efficient your air conditioner will be.
To work out your EER, divide the rated output in kilowatts by the total power input in kilowatts.
The seasonal energy efficiency ratio (SEER)
The seasonal energy efficiency ratio (SEER) takes into account the variation of EER with the load requirement and changes in ambient temperature. It calculates the unit’s yearly energy-efficiency based on a small range of ambient temperatures. Again, the higher the SEER, the more efficient your cooling system will be.
To work out your SEER, perform the following equation: SEER = A*EER100% + B*EER75% + C*EER50% + D*EER25% (where A = 0.03, B = 0.33, C = 0.41 and D = 0.23).
Working out your SEER provides a realistic overall system efficiency rate on a seasonal basis, at part load conditions.
The seasonal coefficient of performance (SCOP)
As with SEER, the seasonal coefficient of performance (SCOP) measures a heat pump’s energy consumption, based on its energy efficiency, over the space of a year. It takes into account temperature fluctuations and standby periods in order to provide a clear indication of your heating system’s typical energy efficiency.
To work out your coefficient of performance (COP), divide the total power input by the total power output. The higher the number, the more efficient the system will be. Working out your SCOP will depend whereabouts in Europe you are based and the average climate. For the calculation of SCOP, the heat pump must be tested at a series of temperatures.
How TEK can help
If you are struggling to work out the SEER or SCOP of your appliances, our trained engineers at TEK are on hand to help. We are air conditioning contractors in Bristol and we understand working this out can be complex but it’s important that you get it right to ensure that you meet current legislation. Doing so could also lead to substantial savings for your business.