What is the Economy Cycle in HVAC?


The economy cycle is one of the energy saving strategies in the operation of heating, ventilation and air conditioning systems. In this strategy, the ultimate goal is to reduce equipment energy consumption by relying more on what’s already available (ambient outside air for space cooling).

Economy cycle in HVAC

When we hear the word economy or economic immediately we think about maximising outcomes, achieving objectives and minimising costs. In HVAC systems, we want to achieve comfort for our occupants while also minimising energy costs. It’s especially the case now where there are energy audits, skyrocketing energy costs and more serious environmental responsibilities.

To achieve economy, it’s about maximising outputs (or achieving the desired output) while minimising inputs. In HVAC systems, the input is often in the form of energy. More energy means more capacity for cooling. However, input could also be coming from other sources especially which is abundantly available. In this case, the outdoor ambient temperature can be used for space cooling to save on energy. As a result, the equipment will require less energy to bring down the air temperature levels.

For the economy cycle program to use, often the minimum required equipment are field sensors (for monitoring outdoor and return air temperature and humidity), DDC controllers, outdoor air and relief air dampers, motorised modulating actuators, outdoor air inlet and exhaust air outlet and ducts and an economy-cycle software. The software is important for delicate and real-time control and activation of the program as well as maximise the benefit from using outdoor air.

There are costs and benefits (and some disadvantages as well) in the use of the economy cycle. For example, if the sensors and control settings are faulty, this could raise energy use because outdoor air was too hot or too cold. Air pollution is also a concern because in this program we’re introducing more outdoor air into the building premises. Even with those possible drawbacks, the potential energy savings are still huge (could be 20% energy savings from AC compressor operation). This also results in lower HVAC maintenance costs because the equipment are being used less frequently (i.e. relying more on outside air instead of the equipment running).
If you’re planning to implement this energy-saving strategy in your building, you can contact us here at ACG Commercial. We will come up with tailored and cost-effective plans for your building.