It was a great pleasure for CEC to be a part of the Kuwait HVAC&R Conference on 8th-9th November, 2107. The convention was an excellent forum to understand the challenges for sustainable building design through reduction of power consumption and discuss the methodologies to overcome them successfully. The central focus of the conference was the role of HVAC system efficiency in sustainable architecture and the need for effective measures by MEP design services to boost the same.
Kuwait has steadily risen to have the highest per capita consumption in the world, which is nearly twenty times that of a regular consumer. There are several factors responsible for this excessive use of electricity, including massive energy subsidies and extensive fuel reserves. Coming to the power-consumer spectrum, the residential sector is found to be the biggest consumer of energy in terms of electricity, with 74% of the total share. Inspecting further, the cooling and ventilation application is responsible for 79% of this sector. It can be thus seen that HVAC systems have a direct impact on the total energy consumed by the country and hence, concrete efforts need to be made to increase their efficiency.
This need is based on the recent Paris agreement for climate control made by a majority of the nations in the world, which aims to curb the global temperature rise by 2020, keeping it well below 2-degree Celsius. As Kuwait is a part of this agreement, it is putting several measures in place to improve building performance. These measures are already practiced in Dubai, by MEP service providers and companies providing renewable energy solutions in construction.
Methodologies for Reduction of HVAC Consumption
The growing need to curb excessive power consumption makes it imperative that the methodologies be based on the sustainability principle; reduce, recycle, reuse.
Understanding this, some of the best practices for HVAC, which are in use in Dubai at present, were discussed at length. These include:
Avoidance of Thumb Rules
Thumb rules are generally useful guidelines people adhere to while designing a building. However, the advent of new technology has made these industry thumb rules rather outdated. It often so happens that engineers come up with innovative solutions to cut power consumption further than required by set standards. Unfortunately, since they might not fit in with the ‘thumb rules’, they are rejected as unnecessary. This should be avoided.
Appropriate Orientation of Glazing in Buildings
Orientation of glazing in the original building design can be such that it provides for maximum percentage of the natural light and ventilation required by the building. This ensures sizeable energy savings with no additional expenses in the capital cost.
Use of Air Curtains to Seal Building Envelope
The use of air curtains is a proven tactic to reduce the thermal exchange through openings in a building, which further reduces the load on the air-conditioning systems and improves energy efficiency in the building.
Appropriate Selection of Material
Optimizing the heat transfer coefficient by selecting the appropriate material for a building can go a long way in retaining indoor heat and reducing power consumption by HVAC systems.
Use of FAHU with Heat Recovery Systems
Fresh air handling units are an important tool which can be combined with a heat recovery system to reuse the air in HVAC systems and thus optimizing efficiency.
Directing the Extracted Air on Condensing Units
Another modification of the conventional compressor mechanism, this is based on the reuse principle as well, which improves HVAC system efficiency.
Use of Inverter-Based Compressor
The principal advantage of inverter-based compressors is that they do not require the frequent start-stops in a conventional compressor, which are the primary source of power drain.
Use of Equipment Having High COP/EER
This might seem obvious, but is neglected in many instances. A high coefficient of performance is directly proportional to the energy saved and hence efforts should be made to use equipment having the best COP, as per the desired application.
Use of VFD for Pumps and Fans
A variable frequency drive when used with pumps and fans can reduce energy losses by a significant percentage. In addition, service life is improved by reduction in voltage surges of soft-start and soft-stop motors.
Precise Installation and Regular Maintenance
The most important aspect of maintaining HVAC system efficiency is by ensuring precise installation and regular maintenance. It is imperative that air filters be changed regularly, belt tensions be checked, and dirty coils replaced for the system to function at peak efficiency.
These are some of the methodologies that can be used without increasing the capital cost of the project, but which can make a significant difference in building performance.
Sustainable buildings are the future of the construction industry and sincere efforts need to be made to incorporate proactive measures to prevent future tariffs against non-compliance with green building standards.