09 Jan 2023 CW Team
First things first: What do developers look for in an HVAC system?
Air-conditioning accounts for the biggest portion of energy consumed by a building – 55-65 per cent, reckons Bishnu Swaroop, President – Technical, Ambuja Neotia. Thus, he identifies energy-efficiency or lifetime cost as the most important criterion when choosing a system, followed by ease of maintenance, capex (as this defines the payback period), ease of installation, cooling capacity and interior design needs.
“Our HVAC system designs depend on the end utilisation of the building (whether residential or commercial), expected load, available earthing arrangement, need for air-conditioning in individual residences, the type of electrical supply the building requires (such as single-phase for normal split unit and three-phase for variable refrigerant flow, or VRF), and ease of maintenance,” shares Devaraja TH, Executive Vice President & HOD, M&E – Electrical & HVAC, Sobha. “Further, we consider the climatic conditions that may adversely affect the electrical installation and thus increase the operational and maintenance cost. Finally, the HVAC design considers the reliability of power supply and redundancy of sources and distribution paths to cater to the need for emergency and standby power for continued operation of systems, as well as the integration of alternate sources of energy, such as diesel generation, solar energy, wind power, etc.”
“We choose a type of air-conditioning for various segments of residential properties depending on various factors contributing to the heat load of those dwellings,” explains V Gopal, Executive Director, Projects & Planning, Prestige Constructions. “Typically, the heat load is impacted not just by the active occupancy but also by passive contributions from building materials, predominantly those that radiate heat.”
So, regardless of the segment of property, Gopal points out that a complete concrete/masonry structure could still make do with high wall splits, whereas a similar-sized unit in glass may entail a more effective centralised air-conditioning solution, that is, variable refrigerant volume(VRV) or chillers.
That said, the HVAC preferences for different classes of real estate are fairly well defined.
In the commercial segment, until about a decade ago, the only option was chiller packages with ductable, fan coil unit (FCU), air-handling unit (AHU) indoor units, says Chandrasekar Narayanan Srikantan, National President, ISHRAE, and Consultant & Certified Energy Auditor, Genex Consultants.