HVAC Systems Applied in University Buildings with Control Based on PMV and aPMV Indexes

Abstract

In this work, HVAC (Heating, Ventilation and Air Conditioning) systems applied in university buildings with control based on PMV (Predicted Mean Vote) and aPMV (adaptive Predicted Mean Vote) indexes are discussed. The building’s thermal behavior with complex topology, in transient thermal conditions, for summer and winter conditions is simulated by software. The university building is divided into 124 spaces, on two levels with an area of 5931 m2, and is composed of 201 transparent surfaces and 1740 opaque surfaces. There are 86 compartments equipped with HVAC systems. The simulation considers the actual occupation and ventilation cycles, the external environmental variables, the internal HVAC system and the occupants’ and building’s characteristics. In this work, a new HVAC control system, designed to simultaneously obtain better occupants’ thermal comfort levels according to category C of ISO 7730 with less energy consumption, is presented. This new HVAC system with aPMV index control is numerically implemented, and its performance is compared with the performance of the same HVAC system with the usual PMV index control. Both HVAC control systems turn on only when the PMV index or the aPMV index reaches values below −0.7, in winter conditions, and when the PMV index or the aPMV index reaches values above +0.7, in summer conditions. In accordance with the results obtained, the HVAC system guarantees negative PMV and aPMV indexes in winter conditions and positive PMV and aPMV indexes in summer conditions. The energy consumption level is higher in winter conditions than in summer conditions for compartments with shading, and it is lower in winter conditions than in summer conditions for compartments exposed to direct solar radiation. The consumption level is higher using the PMV control than with the aPMV control. Air temperature, in accordance with Portuguese standards, is higher than 20 °C in winter conditions and lower than 27 °C in summer conditions. In Mediterranean climates, the HVAC systems with aPMV control provide better occupants’ thermal comfort levels and less energy consumption than the HVAC system with PMV control.

Influence of the Airflow in a Solar Passive Building on the Indoor Air Quality and Thermal Comfort Levels

“…Concerning both studies, the air temperature values calculated by the numerical model and experimental data measured inside the occupied spaces, were compared. Other details of the numerical model and other applications can be found in these studies [58,59,[63][64][65]. Regarding this numerical simulation, only the passive and active solar resources were used.…”

A review of noteworthy/major innovations in wearable clothing for thermal and moisture management from material to fabric structure

“…The conventional way to provide thermal comfort indoors is through installing heating, ventilation, and air conditioning (HVAC) systems. 14,15 These kinds of systems require high cost, a large installation space, and have rapidly increased energy consumption globally (2.3% in 2018, which is the fastest rate in the last decade). [16][17][18] In Europe, indoor energy consumptions is about 40% of total energy consumption with 36% CO 2 emissions, which is expected to increase in the future.…”