consumption. Moreover, cooling and dehumidifying fresh ventilation air compose 20–40% of the total energy load for HVAC in hot and humid climatic regions. However, that percentage can be higher where 100% fresh air ventilation is required. This means more energy is needed to meet the fresh air requirements of the occupants. Heat recovery is getting a necessity due to an increased energy cost for the treatment of fresh air. The main purpose of heat recovery systems is to mitigate the energy consumption of buildings for heating, cooling, and ventilation by recovering the waste heat. In this regard, stand-alone or combined heat recovery systems can be incorporated into residential or commercial buildings for energy saving. Reduction in energy consumption levels can also notably contribute in reducing greenhouse gas emissions for a sustainable world. Greenhouse gases CO2, N2O and CH4 are common greenhouse gases and CO2 is the largest contributor to climate change. Therefore, the greenhouse gas emissions are frequently denoted as CO2 equivalent emissions. Total global greenhouse gas emissions increased 12.7% between 2000 and 2005. In 2005, around 8.3 Gt CO2 was released by the building sector. Moreover, buildings are responsible for more than 30% of greenhouse gas emissions each year in most developed countries. According to another study, buildings in European Union countries cause about 50% of the CO2 emissions in the atmosphere. It is possible to mitigate greenhouse gas emissions by 70% compared to the levels expected to be seen in 2030 if the proper measures are taken. The increase in greenhouse gas emissions due to the high demand for energy use concluded as global warming. In this regard, mitigating gas emissions in the atmosphere stands out as one of the most crucial problems of the world today that should be resolved. Heat recovery systems have a remarkable potential to contribute to decreasing greenhouse gas emissions by reducing the energy required to heat and cool buildings. The Scotch Whisky Association has carried out a project at Glenmorangie distillery to recover latent heat from new wash stills to heat other process waters. They have found that 175 t a year of CO2 will be saved with a payback period of under one year. In another report, it is underlined that 10 MW of recovered heat can be utilized for saving €350,000 per year in emission costs. UK Climate Change Act of 2008 is targeting a 34% reduction in greenhouse gas