title: Modelling, simulation of energy control of HVAC system in building
title: Μοντελοποίηση, προσομοίωση για ενεργειακό έλεγχο συστήματος κλιματισμού σε κτίριο 
Creators: name: Βενιανακη Γεωργια
Publisher: name: Technical University of Crete
Year: 2018

description: Today, due to the rapid weather changes and the way people live, the installation of air conditioning units in enclosed spaces is imperative. The need to protect the environment, reduce pollutants, and economic reasons make it necessary to carry out optimal studies for the design and installation of the air conditioning of a building. The optimal designing study concerns: (i) the optimal sizing and (ii) the optimal choice of air-conditioning technology, taking into account the heat flow balance observed in the building under study, according to its needs of use, climatic conditions during the year and the cost of installing and maintaining air conditioning in its lifetime. The exact calculation of the heat flow between the enclosed building and the external environment, depends on the climatic conditions, the type and the use of each building's interior. Calculation of heat flows is a complex and can be done through available programs known as "Energy Building Simulation Programs (BEMPs)”.

The subject of this diploma thesis is the above study of optimal design and optimum choice of air conditioning technology between three air conditioning technologies: 1) Variable Air Volume (VAV), 2) Variable VFR, 3) Fan Coils Unit (FCU), been put in a two-storey residence of 128.57 m2 as reference building, in three different climatic areas, the cities of: Athens, Andravida and Thessaloniki. The reference building was designed in detail with the free Google Sketch Up program and was energetically modeled using the EnergyPlus free software, according to the specifications of the Technical Chamber of Greece (TEE), taking into account the layout of the building, the construction, the operating schedules, (lighting, HVAC, etc.) and user utility rates, along with weather data, to perform an hourly simulation of the building and estimate utility bills.

The comparative results between the cities showed that: Thessaloniki needs twice the load for heating compared to the other two cities, Andravida needs almost the same loads for both cooling and heating, while Athens needs 28% more freight for cooling compared to the other two cities. In addition, the comparative results between the different types of air conditioning systems have shown that: The VRV system has the lowest energy consumption and the lowest operating cost while the FCU system has the most energy consumption. As far as the VAV system is concerned, it has slightly less energy consumption than the FCU system, but at the same time it has the largest power consumption for cooling between the three systems. Finally, the cost-of-living analysis showed that in all three cities the VRF system is the most economical option, as the cost of living for the first 15 years is 150% less than the second most economical option.

Furthermore, in this Thesis, extensive literature research and testing of the most famous available energy simulation building programs in Asia, Europe and USA, were carried out: (i) EnergyPlus (Europe), (ii) DOE -2 Building Energy Use and Cost Analysis Software (USA), (iii) DeST building simulation tool (Tsinghua University, China), (iv) ESP-r (Clarke and McLean, Europe) and commercial TRYNSYS® (USA).