Is Electrostatic Filter Technology a new future for sustainable and healthy building ventilation?
As we all know, air handling units condition and distribute the air inside a building. They take fresh ambient air from outside, clean, heat, cool and humidify it and then force it through some ducts into designated spaces in a building.
Some air handling unit (AHU) components consume energy. In particular, these include the filters, cooling coils and fan drives, as well as dampers, inlet grilles and heating coils. The resistance to airflow by ductwork also contributes to the total energy consumed.
While building managers, like everyone else today, are looking for solutions to reduce operating costs and run a more sustainable operation, Electrostatic Precipitator (Electrostatic Filter) systems designed for air handling units stand out with the advantages they provide.
For those unfamiliar with the technology, ESP is based on the electrostatic precipitation process, the effect of which is comparable to the attraction of iron filings to a magnetic field. The air passing through the ESP unit is working in two steps:
- First, the ESP unit transfers an electric charge to the particles in the air (ionization)
- Secondly, the particles are captured by the electrostatically charged plates in the unit
This way it collects all particles in the air passing through an ESP filter.
Electrostatic Filter Energy Savings
Airflow resistance and corresponding energy usage of all parts of an AHU are constant, except for the air filters. The resistance to airflow in an air filter increases over time due to dust deposits in the filter. 30% of the energy consumption of the fan in an AHU is due to the pressure drop caused by the air filters.
A standard pocket filter has a pressure drop of at least 110-130 Pa, even when brand new. As the filter gets dirty, this pressure drop also increases. The constant pressure drop of electrostatic filters is 64Pa. ESP units have almost 50% less pressure drop than a standard filter. This provides great energy efficiency. For example, our ESP system has been given an energy rating of A+ by Eurovent (compared to a C energy rating for traditional pocket filters) and is certified to the highest air quality standards – ISO 16890 and more. This improved energy efficiency has resulted in electricity savings of up to 30%.
Return of Investment
A typical small air handling unit has maintenance costs such as filter replacements, waste disposal, AHU cleaning, etc., of around £2000 p.a. Of course, this is just the cost for the maintenance. It also has a cost to the environment. By continuing with traditional methods in ventilation systems, we leave a serious impact on the environment not only because of the electricity we consume but also because the used filters cannot be recycled.
When you install an electrostatic filter instead of traditional filters your maintenance cost will be only £100 for ESP + £170 for coarse filter replacements p.a. Moreover, you will be running a more environmental-friendly operation by avoiding creating recyclable waste.
When you update your AHU’s filtration systems with an ESP unit, you will recoup your investment in as little as 2 years. The ESP unit has a useable life of 20 years and saves you money for around 18 years, which is probably longer than the life of the AHU.
Amazon’s London and Milan offices, JP Morgan’s Milan office, New Istanbul Airport, Nestle, Deutsche Bank’s Milan office and Queen Alia Airport are fitted with ESP technology and making significant cost savings with a reduced environmental impact for their parent companies.
• Low OPEX, CAPEX
• Collect particles from 0.01 µm to 100 µm up to 99% efficiency
• Operate at high flow rates, up to 1400 m3/s
• Operate at high particle loadings, 500 grams/m3
• Low energy consumption, 16 – 100 Watts/1000 m3/h
• Very low pressure drop 64Pa constant even when full