Air treatment systems, commonly referred to as HVACs (heating, ventilation, and air conditioning), are an integral part of maintaining a comfortable indoor environment, regardless of weather conditions or season. HVACs encompass everything from the air conditioner in a house to the large systems found in shopping malls, skyscrapers, and industrial complexes. They are also a crucial component where health regulations require that temperature and humidity be kept at certain levels.
HVACs can be single-function. For example, in hotter regions, one may only want to cool the air, while only heating may be desired in colder regions. However, HVACs are typically multifunction and process air in multiple ways as weather and seasons change.
Some heating systems come in the form of furnaces where fuel is burned to provide heated air through the ductwork, while another option is boilers that heat water for steam radiators, or forced-water systems with baseboard radiators, electric heat, and heat pumps. Furnaces generally burn gas or propane, while boilers use gas or oil to heat the water.
Air conditioning is the process of taking warm air into a system and dispersing cold air. Inside the air conditioner, a fluid such as water is cooled by another fluid called a refrigerant. The conditioner quickly converts gas into a liquid and back again using chemicals that remove warm air from indoors and disposes of that warm air outside. The type of air conditioner we’re most familiar with is the split system, which consists of a wall-mounted inside unit and a larger outside unit. This split system is popular because the noisy components are housed in the outside unit, allowing for a quieter indoor environment.
An important aspect of air treatment is humidification and dehumidification. Humidity can make conditions feel warmer than they really are, driving people to lower the thermostat which drives up energy usage. Excess moisture in the air can also lead to building and property damage, as well as harm your health. While air conditioners can reduce the humidity in a space, a dehumidifier is far more efficient. A dehumidifier draws in humid air and passes it through an evaporator. The humid air containing the moisture is then cooled. The cold dry air then passes through a condenser, heating the air and returning it to the room to gather new humidity or moisture. And the cycle repeats itself until ideal conditions are met. In the case of humidification, moisture is added to the air by passing it over the stream or spray of water which is at a temperature lower than the dry bulb temperature of the air. Ideally, the humidity level of indoor environments should be kept between 30% and 50%.
Another part of air treatment is air purification. The purpose of air purifiers is to remove impurities from the air we breathe. These impurities include dust, smoke, mold spores, pet dander, and pollen, among other airborne pollutants. Traditionally, woven material is used to capture particles as they pass through. Air purifiers for odor that use HEPA (high energy particulate air) and activated carbon filters trap the tiny particles that create undesired smells.
As the effects of climate change worsen and the quality of air reduces as a result of pollution, air treatment systems are transitioning from luxuries to necessities.