A key component in any large-scale commercial building is the design and installation of a system to provide heating, cooling, and ventilation. A common approach, especially in buildings such as skyscrapers, is to utilize HVAC units, which are integrated systems that provide a complete solution for temperature control and indoor air quality.

Most of us are already familiar with HVAC units on a smaller scale, since automobiles also use them. A common characteristic of these units is the use of common vents and ducts to deliver both heated and air-conditioned air, as well as to provide fresh air to an indoor environment inside a car or a building. HVAC units provide affordable solutions to the problem of indoor air quality, since with them it is not necessary to install separate heating and cooling systems.

Additionally, they allow for more flexible control over indoor temperatures than do separate systems. It is common, for example, to shut down and winterize a cooling-only system as soon as autumn temperatures begin to drop, but this leaves you sweltering if a heat wave happens later than expected in the season. Likewise, a sudden cold snap in the summer can make your office building uncomfortable for everyone who works there if the heating equipment has already been taken offline for the season. Scenarios like these ones simply do not happen when HVAC units are in place since both heating and cooling remain available year-round.

Advanced HVAC units can also be set to maintain a certain temperature automatically. Such units will regulate the indoor air temperature by activating heating units in the morning and cooling units in the afternoon, should the daily weather conditions requires it. From the perspective of the end user, the system is simplicity itself. You merely push a few buttons to tell the unit the temperature you prefer, and the HVAC unit, an integrated system, will do the rest. This leads not only to a more stable indoor air temperature, but to significant cost savings since heating and cooling are not dependent on a person's ability to remember to go turn off the heating or cooling when the system has reached a comfortable level. Although HVAC units possess these sorts of advantages as standard features, it would be a mistake to assume that they are standardized in nature.