A holistic approach to HVAC systems

Ensuring excellent air quality involves considering every aspect of the HVAC components and processes attached to a building. In the best systems, all these elements work together to improve indoor air quality, improve comfort, protect health and enhance energy efficiency. John Grenville, managing director of ECEX, explains.

Shortly before his death in 1993, influential American engineer, professor and management consultant Dr W Edwards Deming made a telling point which can be usefully applied in pretty much any situation.

He said: “A company could put a top man at every position and be swallowed up by a competitor with people only half as good, but who are working together.”

As with people, so with mechanical systems – working together is crucial. Individual components and processes play their part in any system, but it is the system as a whole working as one that produces the best results.

Every element of a HVAC system affects its operational efficiency and quality. Of course, this involves focusing on each individual component, but it also means paying careful attention to processes such as maintenance and refurbishment.

One of the main functions of an effective HVAC system is to prevent airborne contaminants from entering a building. This begins on the outside, with pre-filtration media fixed to air intakes blocking larger pollutants.

Primarily used to improve HVAC efficiency, pre-filtration is also the first step in ensuring good indoor air quality – and therefore the comfort and health of building occupants.

Pre-filtration screens – otherwise known as air intake screens – prevent airborne debris, including, pollen, insects, leaves, and so on, from entering HVAC equipment. This maximises airflow to the equipment, which lowers running costs, reduces maintenance time for engineers and cuts energy consumption.

By helping air handling units (AHUs) to work at their optimum, reliant air conditioning and ventilation systems will do their job properly.

They have several key business advantages including maintenance requirements reduced by up to 75%. On top of this, benefits of our own ECEX Air Intake Screens include reduced coil treatment and cleaning costs, energy consumption and cooling tower water treatment chemical requirements.

Once in the room, there are a range of air purification options that help ensure circulating air is safe to breathe. These typically comprise one or more filters and a fan that sucks in and recirculates air. As the air moves through the filter, pollutants and particles are captured and clean air is returned to the occupied space.

But technology is not enough on its own. How that technology is treated also has a huge bearing on the efficiency of the overall system.

There are many compelling reasons to take maintenance of HVAC systems in commercial buildings seriously. Apart from the need to comply with health and safety and environmental legislation, it makes sense to provide comfort for building occupants to avoid complaints and improve productivity.

It also saves energy and therefore operating costs, retains the assets’ value, enhances the business’s reputation, leads to better working relationships and reduces disruption to the business. Increasing energy costs are another good reason to employ an effective maintenance strategy; best practice maintenance can deliver cost savings of 10 to 40% compared with poor maintenance.

An important part of the HVAC systems maintenance process is coil disinfection. While there are a wide range of cleaning options available for businesses, some are better than others.

As air is passed across the coil it is cooled and this can cause condensation to build up, creating the ideal conditions for airborne nasties to accumulate in a biofilm, reducing the efficiency of the coil and potentially leading to an influx of harmful air.

Disinfection of airflow using chemical-free ultra-violet (UV) airflow cleaning systems will prevent bacteria, viruses and organic growth from taking-hold on cooling coils.

Indeed, in the letter sent to the World Health Organisation by the scientific community, improvements to indoor ventilation, as well as the use of airborne infection controls, such as filters and UV lights, were listed as potential safeguards against aerosol transmission of viruses, including coronavirus.

Notwithstanding the protection cleaning systems provide against pathogens, they also improve indoor air quality by reducing organic growth throughout the entire HVAC system.

Finally, a word about refurbishment. An air handling unit upgrade is extremely costly and disruptive, particularly for buildings in cramped city centres where access can be an issue. Besides, generally speaking, replacement is often subject to relatively long lead times. Refurbishment, on the other hand, is less expensive (typically around 35 to 50% the cost of buying new) and more flexible (disruption in an occupied building can, for example, be minimised by ‘working around’ existing conditions).Refurbishment also leaves existing services such as ductwork, pipework and wiring unaltered and overcomes the transport and access difficulties associated with replacing a unit.

On top of this, a refurbishment offers the opportunity to upgrade the existing system to boost performance. The resulting increase in efficiency can result in significant reductions in operational costs and less likelihood of breakdown. The message is: Think carefully before you replace AHUs; there is a cheaper and potentially better alternative.

For more info visit: ecex.co.uk

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