Combined air heating and ventilation systems in well insulated office buildings

Abstract

Heating and ventilation systems are most commonly separated because water has far better heat carrying properties than air. In order to fulfill the relatively high needs of heating energy for a poorly insulated building it was more rational to use water as a heat carrier. Nowadays, when the properties of building insulation increased due to material improvements and more strict building standards, it might be more rational to combine the two systems.

The objective of this thesis is to make the necessary theoretical calculations, find out and compare economic and technological benefits and downsides of the traditional systems and this new approach for well insulated buildings. The aim of this study is to find out the reasonability of combining heating and ventilation into one system. The secondary aim is to provide necessary information for designing and simulating this kind of system.

This study examined a single story office building in Finland. Theoretical methods were used to analyse the systems. A number of studies were researched regarding the same subject. Despite of that, there is not enough information on this subject, which creates demand for this research. During this research university professors were interviewed as well as professional designers that had accomplished real projects that involved both types of systems, making the information provided in this research reasonable and reliable. This study examined a theoretical one story office building. Designs and calculations were made using Magicad software and other calculation programs. Information for product lists and prices were taken from existing companies catalogues.

This research found that simplified combined system migh bring both economic and technical benefits. Approximately 25% of total cost for materials would be saved when designing combined system. Furthermore, in combined system the total supply air required to heat the building was only 20% larger than the one designed to be supplied in conventional system. Research on balancing work with respect to heat distribution and air flow patterns is suggested for further analysis of the topic.