The most common air conditioning system in offices and workspaces is air conditioning based on air-to-air heat pumps.
Heat pumps are capable of transferring heat from one source to another and can achieve efficiencies above 350% in cooling (EER) or heating (COP) compared to the electrical energy consumed, under specific thermal conditions defined by the equipment manufacturer.
These efficiency levels vary depending on the outdoor temperature of the building to be air-conditioned. For example, when using an air-to-air heat pump, the lower the outdoor temperature, the more work — and therefore more electrical energy — the heat pump requires to transfer heat from outside to inside the building.
If the average outdoor temperature is below zero during the winter season, air-to-air heat pumps are not very suitable due to the drop in efficiency. In such cases, geothermal (water-to-air) heat pumps are a viable alternative. This type of system takes advantage of the latent heat stored in the ground, which is higher than the ambient outdoor temperature, to exchange heat and transfer it to the interior of the building to be conditioned.
Energy Saving and Efficiency Measures
- Installing equipment with variable frequency drives (INVERTER-type systems) optimises compressor operation and therefore reduces energy consumption.
- Installing independent systems to control temperature in each room or office.
- Zoning the air conditioning system according to usage.
- Installing the outdoor unit of air-to-air heat pumps in sheltered areas protected from wind or in locations where greater ambient heat can be absorbed.
- Limiting indoor temperatures to 21 °C in winter and 25 °C in summer.
