Over the years, our dad had set up lots of strange businesses; Unlike other owners, he liked being hands-on. He’d toil side by side with the staff to learn more about multiple troubles at the establishments. His best success was supermarkets. He had 6 in strange parts of the country! Being hands-on meant he traveled a lot to check out the operations, & I went with him. At a single of the stores, he had lots of toil done on the air conditioner unit. It was the largest & needed a robust central Heating, Ventilation as well as A/C to keep it cool during summer time & moderate in winter. Unlike other ACs, a supermarket heating & cooling equipment had distinct features. At the door, all of us needed to set up the air curtains system. It would deliver a blast of air to all customers entering on a overheated summer time day. In winter, the same equipment would supply moderate air. The air curtain had a blower fan inside driven by a small electric motor! Next was the supermarket’s central air ventilation equipment that served the whole setup. It was more expansive & required ample time to install & do all the air duct. My dad number one to use the rooftop units that had everything the central A/C needed. These rooftop units had a large fan that would drag fresh air from the surrounding into the supermarket. Once the air reached the Heating, Ventilation as well as A/C system, it went through the air filter. Here all the dirt & dust would remain behind while scrub air goes into the building. The next part is heating the air using a heat pump or pushing it through a cooling unit. The Heating, Ventilation as well as A/C operator had to determine the correct action depending on the season. That was pressing information because I wanted to study Heating, Ventilation as well as A/C systems in school & set up an A/C company afterward.