I should take the air filter out

I recently had some issues with unusually high utility bills, unpleasant smells in the house, & cold spots in many rooms.  Although the furnace seemed to be running non stop, it couldn’t keep up with demand. When I hired an Heating, Ventilation, & A/C corporation for repair, he checked the system & informed me that the problem was holes in the duct system.  These leaks were allowing the heated air to escape before it ever reached the supply vents. He advocated Aeroseal, which is a patented technology that targets leaks from the inside. The process involves pressurized air & polymer adhesive particles which stick to the edges of the leak, gradually build up & complete an effective seal.  The Heating, Ventilation, & A/C corporation started by plugging the registers in the apartment with foam. This would then force any air to escape by way of the holes in the HVAC duct. He performed a pretest on the duct system to determine the extent of the problem, then began the sealing process. He congested the air conditioner indoor coil, fan & furnace to prevent the sealant particles from entering the inner really workings.  Non-toxic, UL diagnosed & approved particles & air was injected into the duct system. The air is put under pressure, which keeps the particles moving & sends them out through the multiple holes. The entire procedure was controlled by the computer & provided the ability to watch the results. After completion, the computer provided an analysis & proof of success. There was no smell, mess or disfigure, & the whole process was handled within a couple of hours.