So Hot? It's Cool
Summer is here, and it there’s anything most of us feel we’ve got to have to survive the dog days of it, it’s our HVAC (heating, ventilation, and air conditioning) system. Though we depend on it to keep us comfortable during our scorching Texas summers, many of us don’t know much about how this system works. So, we thought we’d offer a quick primer, along with some maintenance tips and suggestions.
Without getting too far into the “scientific weeds,” when cooling your home your HVAC system basically operates according to the 2nd Law of Thermodynamics. Reduced to its bare essentials, this law says that heat flows spontaneously from a hot to a cold body.
Think of an ice cube placed outside on a hot day. Heat is drawn to the ice cube and it melts. That’s a simple example of the 2nd Law of Thermodynamics, and that’s basically how your house is cooled.
The AC part of your HVAC system is made up of outside and inside units. The outside unit, usually found to the side or back of your house, contains the compressor, condenser coil, a fan, and various electrical components. The inside unit, often found in the attic or a utility room, contains a fan (or blower) and an evaporator made up of copper coils through which the system’s refrigerant (cooling fluid) flows.
With those basics in mind, your home’s cooling system works as follows. When the temperature in your house rises above the temperature you’ve programmed into the thermostat, the thermostat turns on the system. The fan in the system draws warm air from the rooms of your house to the copper coils in the evaporator in the inside unit.
Simultaneously, the system pumps cold, liquid refrigerant from the outside unit to the copper evaporator coils. Like that ice cube, the refrigerant heats and vaporizes as it absorbs and removes the heat pumped from the rooms of your house. (The 2nd Law of Thermodynamics in operation!)
The cooled air (air from which heat has been removed) is pumped back into your house, and the heated, vaporized refrigerant moves to the outside unit for dispersal into the atmosphere. Outside, as the heat disperses, the refrigerant returns to its liquid state and is pumped back to the inside unit as the cooling cycle repeats itself.
The modern HVAC systems we have in our homes are highly reliable, and taking a few home maintenance steps can help keep them functioning normally. As with any mechanical system, however, problems can develop, and the best way to prevent serious problems and repairs is to have your HVAC inspected and maintained regularly by trained professionals. In addition to extending the life of your system, regular maintenance saves on energy costs, since the system will not have to work as hard, and also improves the air quality in your home.
So, while there are simple things that you can do to maintain your HVAC system like keeping filters and changed and the external unit clear of debris, for most of us professional help is needed. And at this time of the year, many professional air conditioning and heating companies offer inspection and maintenance specials. For most of us, that’s the best way to make sure the cool air keeps flowing during the depths of the sweltering Texas summer.