Why Has UVGI Become Imperative in HVAC Installations Post Covid 19?

What is UVGI

Ultraviolet Germicidal Irradiation (UVGI) is electromagnetic radiation that is used to disinfect (kill) microorganisms such as bacteria, viruses, yeast, mold, and fungi. It is a non-chemical technology with no residual by-products. The use of short-wavelength ultraviolet (UV-C) light to kill or inactivate microorganisms has been an accepted disinfection method since the middle of the 20^th century. Thus, UV lamps for air disinfection (UVGI) have found a huge scope of applications in air purification with rapidly increasing industry acceptance in HVAC applications. In fact, since the advent of COVID -19, UVGI for HVAC has become a highly searched word, and the world has suddenly woken up to its high disinfection capability.

Importance Of UVGI

Ultraviolet light has shown great promise in providing effective disinfection of air and surfaces. In response to the outbreak, governments and companies across the world are taking to several sanitation practices including a solution that has been in use for decades for effective disinfection – Ultraviolet (UV) light. Ultraviolet Germicidal Irradiation (UVGI) is one such technique that has been effectively used to reduce airborne pathogens in healthcare environments. With this technique, light in the 250nm to 280nm wavelength range (also referred to as the UVC range) disrupts the DNA of harmful microorganisms and renders them unable to reproduce, eliminating the spread of infection. ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) recommends the following strategies of interest to address disease transmission: dilution ventilation, laminar and other in-room flow regimes, differential room pressurization, personalized ventilation, source capture ventilation, filtration (central or unitary), and UVGI (upper room, in-room, and in the airstream).

Coronavirus is highly susceptible to germicidal UV irradiation. The table below shows that the susceptibility of coronavirus to UV is greater than 3 times as compared to influenza (common cold) virus.

How In-Duct UV-C Lamp Arrays Affect Air Disinfection in HVAC

As per ASHRAE, In-duct ultraviolet germicidal irradiation (UVGI) systems can be used to disinfect pathogenic particles transported by air moving through ventilation systems. The proper design of these systems is quite important for energy consumption and disinfection performance, according to a recently published Science and Technology for the Built Environment paper. It is a fact that respiratory diseases are a serious threat to public health and have negative consequences on society and the economy. Since we spend most of our daily life indoors, and due to airborne infectious diseases like the current novel coronavirus (COVID-19) pandemic, countermeasures that minimize the risk of airborne pathogen transmission are a must for providing a healthy indoor environment.

In this context, sterilization technologies such as UVGI units installed in ventilation ducts are a promising technology to satisfy those needs. UVGI lamps that emit UV-C radiation (wavelength from 200 nm to 280 nm) inactivate microorganisms by damaging their DNA.

The CFD simulations are a suitable method to quantify the disinfection performance of UVGI systems by revealing comprehensive results about the interaction of airborne pathogens with the airflow and irradiation field. As per the paper, “Evaluation of In-Duct UV-C Lamp Array on Air Disinfection: A Numerical Analysis,” in-duct ultraviolet germicidal irradiation systems are effective systems that are used in the disinfection of pathogenic particles transported by air that moving through the ventilation systems. Proper design of these systems is quite important for energy consumption and disinfection performance. In this study, the effect of four different lamp arrays within a square cross-section ventilation duct on the average UV dose, UV dose distribution, and disinfection rate are examined by using computational fluid dynamics. The standard k-ε turbulence model and the discrete phase modeling are used to analyze airflow and particle distribution within the duct, respectively. Also, Discrete Ordinates (DO) radiation model is employed to obtain the irradiation field formed by each UV lamp. It is disclosed that UV lamp arrangement within duct significantly affects UV dose distribution.

The study, led by researchers from the Queen Mary University of London and Leeds Beckett University, tested the feasibility of UVGI to reduce Covid-19 transmission by analyzing historical published data examining the effect of UV irradiation on coronaviruses. Evaluating all the data, the research team showed that SARS-CoV-2 virus particles found in the air are likely to be susceptible to UVC, and also that the levels of UVC light required to inactivate the virus would be practical and safe for HVAC applications.

Alfaa UV’s ULTRADUCT UVGI Solution

Alfaa UV’s ULTRADUCT solution provides assured single pass disinfection of airborne bacteria and viruses. It is installed in supply or return ducts. The ULTRADUCT also increases the life of HEPA (High-Efficiency Particulate Air) by reducing the load of live organisms.

ULTRADUCT installation inside the duct of an HVAC

Airborne transmission of diseases through HVAC systems is actually much more prevalent than previously thought. Hospital-acquired infections are costing healthcare providers lakhs of rupees per annum and whilst robust cleaning regimes have been adopted, the spread of Tuberculosis, Meningitis, MRSA, Clostridium difficile, Chickenpox, and Influenza (H1N1 and Avian), including Aspergillus and Pseudomonas continue to grow. These infections affect between 10 and 20% of patients and in some cases are fatal.

Benefits of ULTRADUCT

• Improves indoor air quality
• Increases the life of HEPA filters
• Scientifically designed systems are sized using our proprietary sizing tools based on extensive research
• Helps in Sars Covid Protection
• Can target specific microorganism as per need
• Computational flow dynamics (CFD) and UV radiation profile modeling data.
• Scientifically engineered lamp positioning to provide optimum UV dose delivery and maximum kill rate
• Customized designs specifically made for your requirements
• Easy installation into new or existing ducts or AHUs.
• Continuous disinfection stops the spread of airborne viruses

ULTRADUCT UVGI System Application Areas

Some of the industries that would benefit from the use of Air Disinfection Systems include:

• Hospitals and Laboratories
• Food Processing and Produce
• Hotels and Food-Retail Chains
• Shopping Malls and Retail Chains
•  Commercial Spaces, IT Parks and Schools
• Pharmaceutical & Healthcare Industry

Some of Our Customers

Watch this video https://www.youtube.com/watch?v=z3kWRuEem2g for more information about the process and the product to see how these UVGI systems work

There are many reasons to choose Alfaa UV’s UltraDuct UVGI solutions for your air disinfection in your concerned areas. To know about how we can help you create a COVID free space, call us today on 8879336026 or visit us at UVGI Air Disinfection

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