Assessment of necessity for implementing heating, ventilation, and air conditioning systems in churches of Armenia

In continental climatic conditions, ensuring the thermal comfort of buildings of historical, architectural, and cultural heritage is associated with several difficulties.  Buildings and churches that stood for thousands of years, were not cooled or heated but had design features that ensure constant thermal comfort inside, regardless of fluctuations in external climatic conditions. Passive heating was also used in such buildings, for example, in the hot season, massive buildings accumulated heat gain and then gave off heat in the cold season. When restoring historical buildings and churches, we often encounter the need to introduce air conditioning, ventilation, and heating systems, which must provide the microclimate of the premises that meets modern requirements for thermal comfort and energy efficiency. However, such interventions can also have negative consequences since the requirements for the thermal comfort of parishioners and the architectural and historical conceptual integrity of a given building often contradict each other. To solve this problem, collaborative interdisciplinary research is needed to minimize the impact of mechanical heating and air conditioning systems. An evaluation of the suitability of the heating and cooling systems of existing and renovated churches in Armenia was carried out by monitoring the temperature and humidity of the indoor and outdoor air, analyzing the factors that provide comfortable conditions for the people there. It has been proven that conditions providing thermal comfort to people can be achieved without the introduction of HVAC systems. For this purpose, factors providing passive heating or cooling, such as existing natural ventilation opportunities, prevailing wind direction and speed, building materials and thermal mass, etc., were evaluated. An example of the implementation of HVAC systems is described, in which the invasive effect on the originality of the historic building is minimized.