Clean A/C systems to save energy
The energy consumption of an air conditioner depends on several factors. The most important element to consider when buying an air conditioner is the energy label, which is represented on the packaging with colourful graphics to inform the consumer about the energy efficiency of the specific model. Every label contains the following information: the energy efficiency category from A+++ to G, the cooling capacity in kW/h and the SEER rating (the higher the SEER, the more efficient the unit).
Particular attention should also be paid to electricity time bands, taking advantage of the off-peak ones (when the consumption of electricity is the cheapest). Taking them into account, together with the time of use, is another measure that the user can put in place to further reduce costs and energy consumption.
Another essential element that can reduce the energy consumption of residential, commercial or industrial air conditioning systems is maintenance: a topic that Errecom has often examined in depth from different points of view. By now it should be clear to our readers that the proper running of A/C systems does not depend only on mechanical and engineering variables but also on the chemical maintenance carried out on the system. The additives formulated by the Errecom laboratory aim to block the chemical reactions due to the natural decay of the refrigerant gas and lubricants, restoring the original efficiency of the system and preventing refrigerant gas leaks.
However, it is not only mechanical or chemical aspects that compromise the operation of A/C systems but also a factor that is easy to manage yet too often underestimated: dirt. For this reason, among the elements to be considered to reduce energy consumption, we also find the deep and regular cleaning of indoor and outdoor units.
Why do dirty air conditioners consume more energy?
The main reason must be sought in the evaporator and condenser coils. As these metal fins are heat exchangers that transfer heat to and from the refrigerant gas running in liquid or gaseous form (depending on the case), it’s obvious that the presence of sediments and dirt acts as a barrier that blocks their function. More specifically, when it comes to condensers, untreated debris blocks the heat that is released from the refrigerant gas due to the change of state from gas to liquid; in the case of evaporators, instead, it is the heat resulting from the change from liquid to gas that gets blocked by dust and dirt.
By inhibiting their heat transfer function, dirt leads systems to take longer and more effort to produce fresh air, with greater consumption of energy. HVAC technicians must consider cleaning evaporator and condenser coils as one of the fundamental steps of their maintenance plan, considering that the larger the system the bigger the waste, both in economic and environmental terms.
A/C coils: acid or alkaline cleaners?
The most common problem that HVAC technicians face is the extremely wide range of cleaners available on the market and the difficulty to identify the most suitable one for their needs.
First, it’s important to use specific and professional cleaners formulated by companies specialised in the air conditioning sector.
It is then necessary to distinguish between indoor and outdoor units. The latter, in fact, due to the place where it is installed, is exposed to various types of dirt that must be treated with different cleaners. When the need is to degrease and remove dust, smog, pollen, organic residues, grease, and oil it is recommended to use alkaline cleaners.
On the other hand, limescale residues such as salt deposits, rust or cement must be treated with acid cleaners. Anyway, it is recommended in both cases to rinse with water to prevent residues of the cleaner from damaging the surfaces.
As far as it concerns evaporator coils, instead, it is recommended to use only alkaline cleaners.
And how often should A/C coils be cleaned? The frequency mainly depends on the areas where the systems are installed: near the sea, ports, particularly windy, rainy or polluted areas, such as cities, it is more likely that debris, dirt and scale will accumulate on coils, requiring more frequent cleaning. The same applies to evaporators installed in restaurant or hotel kitchens. It’s up to the HVAC technician to assess the different conditions to ensure constant energy efficiency during the season.
And what about the A/C filters?
Obviously, a complete cleaning operation does not concern only A/C coils. Casings, fans, condensate drain, and filters are other components that should be cleaned. Particular attention must be paid to the filters: dirt or dust that obstructs the airflow makes the air conditioner work harder to reach and maintain the set temperature, consequently consuming more energy.
In any case, if you would like to learn more about this topic, Errecom’s ebook is available here: Cleaners – The New Cleaning Standards for Evaporators & Condensers.