RACA Journal February 2020 | Page 31

Feature up quickly with an installation kit. These models contain wheels, which facilitates with moving them to different rooms.” The portable AC dates back to the 1940s, invented by American Robert Sherman. According to Swana, this was to meet the growing demand for household AC units. “Most portable air conditioners are broken down into two categories based on their configuration as single hose or dual hose,” Swana shares. Single-hose AC units use the same hose as both intake and exhaust for air. While single-hose units will still cool the space you're using them in, they will have to work harder to do so, meaning they are not as efficient as a dual-hose air conditioner. On the plus side, they tend to be cheaper and are a perfectly adequate solution for smaller rooms, such as a small bedroom or studio apartment. Dual-hose AC units have one intake hose and one exhaust hose. Because you have to separate the two hoses, these types of portable air conditioners are usually more energy efficient, generally cooling a room approximately 40% quicker than single- hose units, and they are the preferred choice if you're looking to cool a larger room. “Another popular portable unit is an air cooler which uses ice or cooled water to provide the thermal energy that is used to cool the air. These units use a technology known as evaporative cooling,” Swana says. TYPES OF EQUIPMENT “There are various types of equipment, chillers, air handlers, packaged air conditioners, dehumidifiers, fans, heat exchangers, cooling towers and water pumps. The list can be endless on what equipment can be portable,” Makgatho says. Clark Michel from American-based company, Atlas Sales & Rentals says the market has three main types: • Air-cooled portable air conditioners, which exhaust hot air through ductwork. Air-cooled portable air conditioners are the most commonly used equipment because they can be installed almost anywhere, usually in minutes. They are preferred over water-cooled units where water leakage, no matter how unlikely, would be catastrophic (e.g., in rooms that house computer servers). • Water-cooled portable air conditioners, which connect to an external water source. They are best suited for use in facilities with central cooling towers or chiller systems or where the municipal water supply is plentiful and economical. Water-cooled systems do not require exhaust ducts, so they often are specified when there is no convenient way to exhaust hot air out of a room (e.g., in restaurants). Continued on page 31 www.hvacronline.co.za RACA Journal I February 2020 29