| Popis: |
Active and passive cooling methods have been the subject of much investigation. Nevertheless, there remains a significant opportunity to utilise the so-called "responsive building elements" and to arrange for cooperative deployment with downsized, conventional HVAC systems. The integration of an air culvert with an active cooling system along with associated control is the subject of this thesis. The issues studied within this thesis are as follows. The quantification of air culvert thermal efficacy. The elaboration of an integrated system design method that accounts for the transient interaction between the air culvert and the air conditioning systems. The requirement for hybrid system control when deployed within different climates. The ESP-r system was adopted within the present work. A ground temperature model was established for the hot/dry climate location selected and validated against measured soil temperature profiles. A culvert model was derived and verified empiricall y and by inter-model comparison. Results showed that the ESP-r model can robustly quantify the thermal performance of an air culvert. The culvert was then coupled to a residential villa situated in the hot/arid climate domain and its contribution explored. A constant air volume air-conditioning system was then linked to the culvert-building model and used to research approaches to the control of such a hybrid cooling system. A general control strategy was then devised corresponding to specific objectives and constraints. Results confirmed that the final control set-up can be implemented for a culvert/HVAC hybrid cooling system regardless of climate type, with cooling load matching in excess of 85% keeping indoor resultant temperatures within comfort threshold limits. The project conclusion is that a culvert may be deployed in a manner that allows significant down-sizing of conventional cooling plant, thereby achieving both capital and running costs savings without appreciable loss. |
