SA Roofing February 2018 // Issue 97 - Page 25

FEATURES It is important that the roof can bear the load of the HVAC equipment. “These designs are then done – with difficulty at times – to facilitate what is presented,” he says. Morne Meyer, business development manager for Systems and DVM at Fourways Airconditioning, says that a key function of a mechanical engineer is to identify the right ‘type’ of system that complements the building structure. “The HVAC system plays such an intricate role in building structures these days and a lack of planning considerably limits the options availab le to the mechanical engineer,” he says. In instances where the HVAC design is complex, input for plant room space and ceiling void space is discussed and considered during the architectural design phase. “There are many options available from a system type solution to HVAC designers and installers. However, the system design generally determines the void space required or vice versa,” says Cramer. As construction moves into the green space, being energy efficient is a prerequisite from clients. “Because of this, architects incorporate new energy efficient building methods and make use of greener and more energy efficient products available in the market,” says Cramer. Easier said than done Failing to incorporate the HVAC into the initial design can cause many problems – and not just for contractors. “Too often engineers are forced make HVAC systems work that were never designed or intended for a specific building structure. Therefore, the product ends up taking the blame when it does not work,” says Meyer. Some issues that concern HVAC contractors include having access into the roof. Sometimes the plaster ceiling has already been installed, and it may require them to cut through or break the ceiling, which of course causes damage. “There are times during the construction phase with fast-tracked programmes, where roof structures are in place, but the sheeting or tiles are not. Mutual respect by all trades (including the roofing contractor) ensures that damage to other trade works is not done,” suggests Cramer. Meyer explains that sometimes the roofing contractor may damage the existing HVAC system by either damaging piping (gas or water) or ducting. “In both cases it impacts the whole HVAC system greatly and it can be very costly to repair. More so in the case of chilled water systems because in most cases you need to repair the ceilings, furniture and piping,” he says. “Some poor installations – where HVAC contractors have cut corners to save costs – highlight hideaway air conditioners that do not have return air ducting. The air is supplied into the room, but the air is returned to the air conditioner from the hot (or cold air in winter) ceiling void. This adds excessive load to the air conditioner, making it ineffective and expensive to run,” Parry explains. Drainage is a big concern on any structure. The system needs to drain the condensate collected in the drip-tray on the RESIDENTIAL // COMMERCIAL // INDUSTRIAL FEBRUARY 2018 23