W hat do we expect from our AC systems? Should be simple, right? Depending on when and where you’re asking this question, your answer could be cooling in the summer, heating in the winter. Yes? – but let’s dig deeper.
Heating, Ventilation, and Air Conditioning systems – HVAC for short – have come a long way since 1902 when Carrier invented the modern air con. These machines have made the impossible possible, quite literally. Unbearable summer heat has long been a thing of the past. Mercury-raising temperatures and glass-fogging humidity are merely an inconvenience to overcome nowadays with ever more efficient and greener AC equipment. It’s a race to the top for living comfort, air quality, and environmental sustainability with AC manufacturers worldwide. But do these climate making machines perform as we need them to? Are we using them properly? And does the facilities management industry in particular and end-users in general have realistic expectations from air conditioning equipment?
‘My AC isn’t working’ is a typical overused and misleading complaint in any facilities or property management help desk. It says so much with so few words, doesn’t it?
This request could be solved with basic over-the-phone series of questions: the tenant didn’t set the thermostat properly, causing the unit to blow uncooled air, for example. It could be a bit more technical and require a quick troubleshooting visit from the AC maintenance team, and problem solved within a few hours at most.
Otherwise, it could be an isolated incident or one of several calls logged that afternoon relating back into a bigger issue with the building’s cooling – longer fix time, still manageable though. In brief, ‘my AC isn’t working’ is a common problem with many possible outcomes – easily solved by any maintenance team worth their salt. Until it isn’t.
My father, who’s been in the construction and maintenance industry for over four decades, always said: “The structure is the foundation of any building. The MEP installations are its living, breathing heartbeat.”
As with our body’s organs, MEP installations need to be looked after regularly, taken care of when any issues arise, and trained regularly to improve their performance and enhance their fitness level.
That last part sounds a bit confusing, but it will make sense in a minute. When you want to run a marathon, you need to train your body for it. You cannot go from couch potato to sub-4-hour marathon in one leap. You could, but it would hurt everywhere. Ideally, you build up your training – increasing your lung capacity, enhancing your running posture, strengthening your muscles, improving your threshold heart rate, etc., over the course of an 8-week program.
You align your reality with your expectation. You work hard and achieve what you set out to do. Like your organs, MEP installations need a lot of TLC (tender, love and care) to perform and live out their life cycles.
Proper maintenance is undeniably key, that’s something anyone in the industry will agree on. However, aligning our expectations with reality is a tactic that hasn’t had its time in the sunshine, yet. Aside from the preventive or predictive maintenance – the TLC you can gift to your assets, we need to understand how they were designed, selected, installed, commissioned, and operated.
A lot of steps to be considered but all crucially important. The first step is when the consultant or engineer on a project, ranging from big complexes to single villas, creates the design, writes the specification documents, and issues the drawing.
The second step is when the contractor selects the equipment, notably the AC system in our example here, from water- or air-cooled chillers to VRV systems, and anything in between. The marriage of these two steps is essential yet overlooked or even rushed.
If the AC is designed to run at 99% capacity, if the calculations do not factor in the incoming municipal water temperature, if the design brief did not factor in that the occupant wants to achieve an 18 °C without any excess humidity, if, if, if… Numerous factors need to be considered in the early stages that will have a direct impact on the performance of the system during building occupation later on but also on the expectations of the occupants. We’ve dealt with over- and under-designed cooling capacity in all kinds of projects.
The consultant, fearful of the boiling summer temperatures, selects a cooling system with 150% more load than actually required. The result? A property owner struggling with higher bills.
On the other end of the spectrum, you may have a system that’s designed to run at full load in the summer. Running a cooling system at 100% is not the most efficient, yes. But also, what if you factor in an efficiency drop of 1 to 3% per year depending on use and maintenance. The result is cooling that doesn’t keep up with demand and a lot of upset occupants.
Let’s look at a homeowner living in one of the finest gated communities, in an idyllic 5-bedroom villa. She has paid good money for 5-star consultants and contractors to build her family’s new home. They didn’t spare an expense on anything, marble and kitchen appliances from the finest quarries and factories in Italy, sanitaryware from top German brands, chandeliers encrusted with Russian precious stones, water features and plants shipped in from Spain – well everything’s been carefully chosen except their AC system selection. The AC manufacturer is a good one undeniably – premium engineering, innovative R&D, state of the art factories, all the works. But the selection was sub-par. The fresh air handling unit was not selected knowing that this homeowner likes chilly temperatures in the summer.
The humidity being blown in by the unit was causing the special paint to become moldy and develop cracks. Similarly, the installation of the AC units and controls was far from ideal. The interface between the AC controls and smart home automation was not implemented correctly. The AC cuts off during the warm months because the temperature reading is from the decorative thermostat instead of from the return air duct. A long list of faults meant this homeowner paid top-Dirham to have an unpleasant living environment. Had these issues been taken into consideration early on, the selection of the AC system and its installation would’ve meant a much more comfortable atmosphere.