Design and Analysis of an Integrated Heat and Energy Recovery Ventilation System with Economizer Control for Net-Zero Energy Solar Houses

摘要

There is a requirement now within residential and commercial building sectors to be as energy efficient as possible. Government organisations are issuing more stringent energy efficiency regulations, including the mandatory energy efficiency requirements in the National building Code of Canada (NBC); supplementary SB-10 code requirements in the Ontario Building Code (OBC); and National Resources Canada (NKCan) administered standards, including K-2000, the EnerGuide Rating System, and the ENHKGY STAR for New Homes. R-2000, which is a voluntary standard for residential houses, includes requirements such as energy efficiency, indoor air quality and the use of environmentally friendly products and materials. As these standards and regulations are becoming more stringent, the focus has shifted towards building airtight homes to provide significant energy savings. While an airtight house does offer significant savings, it also causes indoor air quality (LAQ) issues due to a lack of adequate fresh-air delivery through the cracks. Therefore, mechanical ventilation becomes vital as evident by its requirement in all these standards. Ventilation systems that are currently available in the industry are heat recovery ventilation (HRV) and energy recovery ventilation (ERV) systems. HRV's can be equipped in homes to recover sensible heat from the exhaust air onto the incoming supply air, whereas ERV's can recover both moisture and sensible heat from exhaust air to be used in the fresh incoming air in order to maintain the indoor air quality and reduce the energy costs. As well as an economizer mode for free cooling when suitable conditions are conducive. A combination of the individual HRV and ERV systems would be beneficial, which can lead to further energy conservation. Hence the purpose of this project is to design and develop a prototype which will be utilised in net-zero energy solar houses, and it will be tested in the Ryerson University campus lab and at the TRCA Archetype House in Toronto. The control system will be combined with the HRV, ERV, and Economizer with the Air Handling Unit (AHU) which can control the zones separately and have features like recirculation between zpnes to recycle the heat and reduce the energy costs. In order to do this project, a conceptual design of the combined system will be established followed by schematics, controls systems and then finally the specifics like fan rating, the AHU capacity etc. A model will then be prepared in 2D and 3D, which will later be used in manufacturing of the prototype. The model will then be tested to obtain data to determine its benefits and efficiency under different weather conditions. An Excel based program, called TRVE,, for conducting preliminary analysis and potential benefits of the proposed HRV/ERV/Economizer ventilation system was developed. TRVE was used to determine when, where, and how such proposed system could be beneficial in different regions of North America.