Many treatment technologies exist for particulate matter capture from the flue gas. Heat recovery from flue gases is a significant advantage of scrubber technology, which promotes energy efficiency increase of the combustion unit. The amount of recovered heat depends on heat and mass transfer in the scrubber. This paper presents the investigation of innovative small-scale flue gas treatment technology—fog unit. Households produce significant share of particulate matter in Europe. Therefore, there is a need to provide flue gas treatment technologies for domestic boilers in agreement with EU directive 2009/125/EC. Experimental research was done to identify the performance of proposed technology depending on inlet water flow rate, gas flow rate, water temperature, droplets diameter and water–gas flow ratio. The regression equations were developed based on performed data analysis. Equations can be used to predict the capacity of fog unit, outlet water temperature and outlet gas temperature.