RACA Journal February 2020 | Page 33

Feature Continued from page 29 • Evaporative coolers, which use an internal or external water source to provide cooling and a fan to push air across a space. Although their performance is not comparable to that of portable air conditioners, they can provide a simple, low-cost cooling option for specialised use—most commonly, for outdoor areas where the budget or power supply is limited, as they can run on standard residential current. Warehouses are another common application for these units. PORTABLE VS. FIXED The main difference between a fixed unit such as a split AC unit and a portable unit is that on a split unit, the condenser and the evaporator are separated with the condenser being placed outside rejecting the hot air and evaporator inside supplying the cool air. The portable unit is self-contained with both the condenser and evaporator compacted in one unit. A hose is attached to the back of the units to carry out the hot air from the condenser. This hose is usually taken out through a window. “Portable air conditioners often use more electricity to cool the same square meter space compared to a split unit. This is mainly because they generate waste heat indoors instead of outside as the compressor is located inside the unit, creating more overall heat for the unit to deal with. Fixed units require certified installers to fit them into buildings. This results in extra costs making it expensive and less convenient for customers to install a fixed unit as compared to a portable unit which is a plug and play,” Swana explains. The list can be endless on what equipment can be portable.” - Kagiso Makgatho, Aggreko “In terms of actual performance, the equipment is fairly similar. However, modifications are made to allow for easy movement, quick installation and in some instances, wheels placed at the bottom allow them to be moved. Other types have cages built around them to ensure they can be durable and also provide protection against theft and damage during transit,” Makgatho enlightens. Additionally, portable units have the same functions as spilt units like heating, cooling and humidity control. “As previously mentioned, the main advantage the portable unit has over the split unit is mobility,” says Swana. Swana says that the key components that are used in portable air conditioners; include compressors, condenser and evaporator coils which act as heat exchangers, two fans for blowing cool air and extracting hot air, louvers which control Continued on page 33 Portable HVAC equipment is often used on construction sites. www.hvacronline.co.za RACA Journal I February 2020 31