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Clean coils = clean air = cool efficiency


Vern Klein of market leader Advanced Engineering sums up the case for maintaining clean coils… and offers solutions for every situation.

While the effects of ‘dirt’ – in its many forms – on air conditioning and refrigeration coils can be as complex as the systems themselves, there is a single answer to the problems it causes: preventative maintenance. More of that later, but let’s begin by summarising those problems.

1. Dirty coils cost money, in terms of bigger energy bills, higher Climate Change Levy charges and a shorter life for the system and its components.

2.Dirty coils reduce a system’s ability to perform the functions for which it was designed, including maintenance of constant temperature. And far from keeping the environment fresh and clean, they introduce smells, allergens and disease microbes that reduce Indoor Air Quality (IAQ).

To understand these issues more fully, it is necessary to look at the differing functions and circumstances of condenser and evaporator coils.

Condenser coils
The condensing coil’s role is to dissipate heat absorbed from the refrigerant. Any build-up of dirt on its fins and tubes acts as an insulating blanket. This raises the condensing temperature. The resulting rise in condensing temperature will cause the compressor to work harder and operate for longer to achieve the same cooling effect. That means both higher running costs and greater wear on the compressor – an expensive item to replace.

Air cooled condenser coils and condensing units move large volumes of air. The air is usually unfiltered. Any suspended dirt or debris will be deposited on the coil. Condensing units in kitchens have the added problem of backed on grease.

Evaporator coils
In an evaporator coil, the refrigerant absorbs heat from the environment. Evaporators suffer a reduction in airflow if their surfaces are dirty. This causes the evaporating pressure to drop, leading to a lowering of the cooling effect and a need to run for longer to meet the user’s need. That means a higher energy demand and higher running costs. At its extreme, the evaporator can freeze – its fins and coils become covered in solid ice. At this point there is a high risk of the compressor failing and water damage to the building fabric.

As well as causing damage and expense, dirty evaporator coils are breeding grounds for microbes – which can generate offensive smells, trigger allergies and spread airborne diseases.

The cost of dirty coils
Replacing damaged compressors and other components is very expensive – and so is the accumulating cost of inefficient energy use. Research shows that dirt can increase a system’s consumption by up to 30%. To add to the high fuel bills, there is now a related Climate Change Levy charge reflecting the level of energy use. New building regulations for England and Wales, entitled “Conservation of Fuel and Power L2”, require facilities managers to keep records, which will provide the basis for action to improve energy consumption and CO2 emissions. Of course, there is also an environmental cost, which should concern us all: the effect of depleting fossil fuel resources and increasing global warming.

To summarize – Most importantly dirty coils cause an increase in energy consumption, up to 30% in some cases. This means higher fuel bills.

The government has introduced a number of schemes to control the amount of energy that this country consumes – most of them are targeted at industry. We will look at these in more depth in the second article in this series entitled Good for business… good for the environment.

A solution for every situation.
As I said at the beginning, the answer to all these problems and costs lies in a planned regime of coil cleaning. My own company Advanced Engineering can supply a range of treatments to deal with every circumstance and every part of the system. Here are just a few examples:

General and routine maintenance.
General cleaners include EnviroCoil, using biodegradable surfactants, has strong environmental credentials. Its non-acidic formulation will neither attack the coil nor harm those using it.

Heavy duty cleaners.
To tackle stubborn dirt on neglected coils, something stronger is needed. HydroFoam acid cleaner, developed specifically for air-cooled condensers, leaves coils shining and bright. HydroKleen alkaline cleaner is the perfect treatment for dirty or greasy AC&R systems, foaming out dirt and dissolving grease and oil.

Detergent and foaming cleaners.
HydroCoil is one of a number of products which contain surfactants or detergent to speed up cleaning. A good general-purpose cleaner and deodoriser, it is alkaline based and will treat even the dirtiest of coils.

Combined cleaners and disinfectants.
For indoor coils, disinfection is as important as cleanliness. Like all advanced disinfectant cleaners, CondenCide and RTU Condenser Cleaner and Disinfectant are certified to British and European standards as fungicides and bactericides. Alkaline based, they are perfect for cleaning, disinfecting and deodorising metal surfaces, particularly in food preparation areas.

Long-term bacterial control treatments.
Pre-Clean and StayClean are products which prevent microbial growth and smells for several months after each treatment.

Solvent cleaners.
Where grease is a big problem, and particularly if coils are close to electrics, a solvent-based cleaner is a good option. GreaseGobbler, for example, is non-conductive, non-flammable and quick drying. It dissolves grease on contact and is ideal for condensing units in kitchens.

Other products address such specific tasks as descaling, ice machine cleaning, corrosion control, condensate tray treatment and much more. If this all seems very complicated, don’t worry: Advanced Engineering can provide detailed information on the whole range and can even arrange a free site survey – with no obligation – to identify the right solutions for you.

For further information, contact Advanced Engineering Ltd, Guardian House, Stroudley Road, Basingstoke, Hants, RG24 8NL, UK. Tel: +44 (0) 1256 460300 Fax: +44 (0)1256 462266. Email: [email protected]