We are fortunate we are living in the GCC region, where the respective leaderships of the constituent countries have taken good care of citizens, residents and tourists alike during this terrible pandemic. The structured pandemic-specific public health initiatives have resulted in faster recoveries of those infected, when compared to previous such recorded instances the world over.

Dharmesh Sawant

A plus of the recovery is that the property market is bouncing back with numerous launches, especially in the villa and townhouse segments. The region’s real estate sector is driven by powerful sentiments. Many expat residents prefer to move into their homes rather than renting one.

Even though this is one of the more important decisions for the family structure, considering that hard-earned money goes into the purchase of property, buyers typically do not have much of a say in many aspects of construction. Only viable features, like doors, windows, kitchen tops, tiles and cabinet finishes are covered in the contract; the buyer has no say whatsoever, contractually, to access the design of, say, the air conditioning system.

The situation is a bit odd, because it is the buyer or end-user who is paying for MEP services and yet is unaware of such important aspects as the lifespan of the air conditioning system, IoT compatibility, independent controls and serviceability. In such circumstances, it becomes an even greater responsibility for project managers of developers, consultants, contractors and suppliers to ensure the required checklists are ticked to ensure the buyer or end-user enjoys a trouble-free experience, energy efficiency and low total cost of ownership (TCO).

However, based on my experience as a buyer, with a background in the HVAC industry, I find many important criteria are overlooked, despite multiple levels of evaluation.

I would like to list some of them…

Combining two bedrooms with an air conditioning unit in three-bedroom apartments, villas or townhouses

This is a common design practice in the industry. I understand the reason behind this is to reduce the capital cost, as it will reduce not only one indoor unit but will also reduce one outdoor unit, and the respective piping, cabling, isolators and breakers from the purchase list.

In the case of a multiple-villa compound, air conditioning can be a substantial cost, but the downside is the lack of availability of an independent temperature control zone. In the case of combined bedrooms air conditioning unit, where one of the rooms is used by children and the other by grandparents, issues of a serious nature can crop up. Both age groups require extreme temperature settings, and a combined setup leads to inconvenience. Also, in the event of a need for isolation, there is a high possibility of contamination from mixing of air in the two rooms.

Absence of IoT compatibility

Nowadays, everything is available on hand-held devices, including payment gateways, vaccination card, National ID card and residence visa. In short, digital is all pervasive. If so, why not air conditioning control and monitoring, especially in the case of apartments and villas?

People travel to their home countries on vacation during the hot and humid summer months. It is recommended they keep the air conditioning running continuously – even 24×7 – to prevent ingress of moisture and the resultant invasion of mould.

It is well understood that running the air conditioning continuously leads to wastage of energy. Now, if air conditioning units are part of an available mobile app-based control system, they could be operated for limited hours, including a system of weekly programming, to maintain the correct humidity level in the room.

This feature is available with most manufacturers of air conditioning systems. But I still find to my dismay that AC specs in commercial villa compounds are bereft of any controls. Typically, the project ends up with an air conditioning system that cannot be hooked on to an app-based controls system. The party affected by the lack of thought and intent is the buyer or the end-user.

Serving the living room and the maid’s room with the same unit

The pandemic has led to an increase in standalone houses, as opposed to apartments. In some of the mega townhouse projects, I have seen developers combining the living room and the maid’s room, on the ground floor, with one air conditioning unit. There are three problems in this design…

a) Inefficient design: The air conditioning unit will run during daytime, as the living room is invariably occupied. It will run in the nighttime, as well, as the maid’s room is occupied. This approach leads to loss of valuable energy. Also, continuous running of the unit will reduce its lifespan.

b) Lack of redundancy: In case of malfunction of the air conditioning unit, owing to parts failure, leak in the pipeline or electrical problem, the whole floor will be without air conditioning. A smart way of sorting out the problem would be to install a unit to serve the maid’s room, the passage and the open kitchen; another unit would supply to the living room. In the event of failure of one unit – say, the one in the living room – the space would still have some cool air flowing in.

c) Noisy and bulky machines: If one unit is serving the whole ground floor, it is a given that it must be bigger, which inevitably would mean a higher air flow noise. The bigger height of the unit would also bring the false ceiling down in the kitchen area. Typically, architects and interior designers exert pressure on other stakeholders and generally do not compromise on the height of the false ceiling. As a result, the indoor unit is kept in a cramped attic, leading to poor access to the filters.

No service data logging capability

“After sales service” is the least of concerns for any developer, consultant or contractor, because the AMC is the responsibility of the buyer or the end-user. When it comes to DX/VRF systems, it’s an old-school, reactive service regime. AMC is treated as just a matter of cleaning the filters, cleaning the condenser coil with water and checking the cables. That’s it! Oh, and the AMC-provider will repair the units in the event of a breakdown! In fact, they like the opportunity of a breakdown, because they can earn more, as spare parts are usually not covered in the AMC.

Nowadays, most manufacturers of air conditioning units can provide data loggers, which can help service providers get information on important service parameters, like suction and discharge temperature, ambient temperature, refrigerant inlet and outlet temperatures, compressor frequency and EEV opening. If these data loggers are connected to Wi-Fi, the parameters can be accessed remotely in real time.

The data harnessed can help the service providers analyse the performance of the units and predict potential degradation or failure. Typically, the cost of a data logger is not more than AED 1,000 per villa or townhouse. Even if developers cannot provide data loggers, they must at least ensure the units are digitally compatible for a later-day intervention.

Connection of fresh air to the indoor unit

Generally speaking, bathrooms in townhouses don’t have an exposed wall. So, the only way to bring outside fresh air to the indoor unit is through the duct running from the roof or shaft. I have seen many projects having a central fresh air fan, supplying untreated fresh air to all the indoor units through ducts in the shaft.

The problem with this design is that when the first-floor bedroom air conditioning unit is off, hot and humid untreated fresh air is dumped in the attic. It is then only natural that many residents complain about the smell of stale air and mould in the attic. This problem is very common in August, September and October, when Relative Humidity is high.

Given this situation, it is better to ensure independent duct connection to each indoor unit, which can suck the fresh air from the open shaft.

Some installation practices to reduce operating electrical consumption

As an engineer, I see many MEP designs in townhouse and villa projects. I do believe that adopting simple steps can help reduce electrical consumption through operating air conditioning systems…

a) Directing the central exhaust behind the living room outdoor unit.

Since the unit would be running during daytime, the exhaust air discharge coming at 24 degrees C could help reduce the condenser unit suction air temperature, leading to reduction in electrical consumption.

b) Locating the outdoor unit in such a way that it gets shade between 2pm and 4pm.

Doing so would ensure a drop in the condenser unit suction temperature by at least 5 degrees C. Some of the above points are simple and logical, but I still find the design to be otherwise. I am sometimes surprised that design faults come from reputed developers, whose core pillar is sustainability.

One of the reasons for design flaws might be capital cost, but I believe some basic guidelines should be established and, equally important, must be adhered to without compromise and consideration of cost. By the way, the cost of air conditioning equipment in the sale price of a townhouse or villa is approximately two per cent. Of course, there is a possibility that the adoption of some of the measures I have discussed would increase the cost of equipment by 0.5%, but it is still minimal.

Pit the cost against the tremendous satisfaction a buyer or end-user would draw through experiencing clean and healthy air, delivered though operating the system in as energy efficient a manner as possible, and the result could be repeat customers and word-of-mouth promotion – in effect, buyers would be unrecruited marketing personnel.

Many a times, consultants and developers focus only on specific brands, but I do believe it is more important to focus on the design of the air conditioning system. I say this, because if the design is wrong, however good the brand may be, the cost of rectification will be extremely high and painful.

The writer is Sales Director, VRF (UAE, Oman & Qatar), Hisense Hitachi Air-conditioning Company. He has written this article in his personal capacity as an enlightened end-user, though, by virtue of several years working in the HVAC industry. He may be contacted at dharmeshsdd@yahoo.com.