Zoned HVAC systems, the ultimate way to achieve comfort and save energy

A study carried out by the University of Malaga and Airzone demonstrates the efficiency of independent temperature control in the different spaces of a building

The energy research team from the University of Malaga (UMA), together with a group of experts from Corporación Empresarial Altra (Airzone), participated in a conference on energy sustainability in air conditioning systems held in Milan (Italy) in July 2020.

The meeting, organized by the Italian Association of Air Conditioning, Heating and Refrigeration (AICARR), which aims to create a debate platform on the present and future of the air conditioning sector, is part of the 37th edition of the National Congress which is being held under the title "Objective 2030: scenarios, technologies and strategies for energy sustainability in air conditioning" this year.

The head of Development and Training at Airzone Italy, Davide Truffo, presented the results of a scientific study which shows that smart zoning systems not only guarantee better thermal comfort, but also reduce energy consumption.

The study was carried out by the researcher from the University of Malaga, Francisco Fernández, and by several members of the Airzone team, including the Director of Product Quality and Energy, José Miguel Peña; the Project Manager, María del Carmen González; the Energy R&D engineer, Juan Bandera; and the speaker Davide Truffo.

Entitled "Impact of zoned control systems on thermal comfort and energy efficiency in residential buildings", this study sets out two main conclusions: zoned air conditioning offers greater comfort and it considerably increases energy savings.

This conclusion is reached by comparing the operation of a zoned system with a non-zoned system.

What is a Zoned HVAC system and how does it work?

The air conditioning systems with zoning, as the name indicates, allow to control the temperature of each space of a building independently. They only require the installation of a thermostat by zone.

Thus, different rooms in the same building can be at different temperatures. In addition, the devices in certain rooms can be kept powered off, without interrupting the operation of the rest of the building's air conditioning devices which can remain active. Consequently, the energy consumption and economic expenses are reduced.

These systems work thanks to the implementation of communication gateways that connect the air diffusion equipment with the various thermostats, which measure the temperature of each space and regulate the operation of each machine in the system according to demand.

Comparison of zoned and non-zoned systems

After analyzing the operation of zoned and non-zoned control systems separately, considerable differences in energy savings and comfort values are observed.

Non-zoned HVAC systems which cannot allow to choose the temperature independently in each space of the same building, are able to offer comfort only in some areas of the building. Compared to these, zoned systems that act on user demand offer comfort in all rooms. According to the study, the difference in the comfort level can be up to 70%.

Therefore, after carefully comparing the spaces with different systems, the research concludes: "comfort in zoned air conditioning systems is always greater than in non-zoned ones".

Something similar happens with energy consumption.

In the three different scenarios analyzed in the study (a building in Milan, another in Rome and a last one in Naples), a significant energy saving has been detected in the spaces with zoned systems compared to the non-zoned ones. The average saving for heating systems is between 17% and 21%, while in the use of cooling equipment a saving of up to 73.5% has been observed for determined areas.

Experts' opinions

According to the researchers and speakers, studies such as that carried out by the UMA and Airzone are of significant importance to the industry, since, as Juan Antonio Bandera points out, "research and innovation in the field of air conditioning systems are vital for reducing energy consumption in buildings and achieving the goal of constructing Nearly Zero Energy Buildings (NZEB)".