Starting in the late 20th century, synthetic oils became more popular for some compressor systems. This was largely due to the ability to create or formulate specific oil characteristics for industrial, medical and consumer uses. 

Ventilating homes and commercial buildings may commonly be considered a matter of circulating air for the comfort of the people who use the buildings. HVAC design engineers, however, generally are trained to understand the importance of designing and monitoring ventilation for the good of the structure itself as well. 

A network thermostat, sometimes called an Internet thermostat, allows property owners to control the temperature of their heating and air-conditioning systems from other locations. This is done through an Internet protocol network accessed by computer or mobile phone. The capability of remotely controlling building temperatures allows for greater environmental management, enhanced energy efficiency, and money savings. Linked with other home automation devices, such as lighting systems or appliances, these devices offer greater property automation through preset programming that might automatically activate furnace or air-conditioning systems during typical hours of occupation.

Thermostats not only read temperature, but can also control the activation and deactivation of equipment. With the use of Internet technology, temperatures can now be controlled by accessing equipment through a Web server, by secure interface through a Web browser. This allows homeowners and property managers to control their environmental systems from virtually any location with an Internet connection.

An ionizer is a type of air filter that uses high voltage to charge molecules in the air, to help clean them. Since they are using electricity, rather than a passive form of filtration, they do not require filters that need to be regularly changed. As a result, they are very convenient for a number of different uses, most especially in the house or in the car, and there are a wide range available on the market. Depending on a number of factors, an air ionizer can cost anywhere from around $50 US Dollars (USD) to many hundreds of US Dollars.

A blower fan has three main components: the fan, by which air is moved through its blades; a powerful motor with lubricated moving parts that spin the fan blades; and a power supply that provides electrical power to the motor. A metal or plastic housing contains the assembled parts.

In addition to cooling a home and helping a home to be more energy-efficient, solar attic fans can also reduce the amount of moisture that is allowed to collect in the attic. Attics often attract residual moisture from a home. Over time, this moisture can cause extensive if left unchecked and untreated. An attic ventilation fan helps to draw moisture out and away from the interior of a home, creating a drier, less humid environment in the attic.

Grill or grille air registers are typically made of wood or metal. Many of these have wide, square holes rather than linear slats or slots in order to distribute a larger air flow. A wooden air register is the ideal choice for a duct located on a wood floor. Stainless steel or aluminum air registers may blend better on gray stone or slate floors. The different materials, colors and finishes of air grilles and registers allow home designers to create cool or warm looks to suit specific decors.