Frequently Asked Questions (FAQ)

What is UV Water Treatment and How Does It Work?

UV (Ultraviolet) water treatment uses UV light to inactivate microorganisms like bacteria, viruses, and protozoa in water systems. By exposing the water to a specific wavelength of UV light, the DNA of these pathogens is disrupted, preventing them from reproducing. This method is chemical-free and commonly used in potable water applications, commercial HVAC systems, and industrial process lines to maintain clean microbe free water.

What Is Sidestream Filtration in HVAC Systems?

Sidestream filtration is a process where a portion (or “side stream”) of the main water circulation loop in an HVAC system is diverted through a specialized filtration unit. This helps remove suspended solids, debris, and contaminants without having to treat the entire system volume at once. Sidestream filtration improves heat exchanger efficiency, reduces fouling, and prolongs the life of HVAC equipment.

How Does Inline Particulate Filtration Differ from Sidestream Filtration?

Inline particulate filtration is installed directly in the primary water flow, filtering all the water passing through the system.
Sidestream filtration, on the other hand, treats only a fraction of the flow, continuously removing contaminants over time.
Which method you choose often depends on flow rate requirements, budget, and system design constraints.

What Is Water Conditioning?

Water conditioning is an umbrella term for treatments that alter the properties of water—typically aiming to reduce scale, corrosion, or biofilm without necessarily removing minerals like calcium and magnesium (as a water softener would). Water conditioners often use physical or chemical methods to modify the way minerals behave, helping to prevent limescale buildup and improve system longevity.

What Is the Difference Between Water Softeners and Water Conditioners?

Water Softeners: Use ion exchange to remove hardness ions (calcium and magnesium), replacing them with sodium or potassium ions. This leads to reduced scale formation and improved efficiency in boilers, chillers, and other heat-exchange equipment.
Water Conditioners: Do not remove minerals; instead, they change the mineral structure or prevent them from depositing as scale. They’re often salt-free and can be more eco-friendly but may not achieve the same level of hardness reduction as a traditional softener.

How Does Chemical Dosing Work in HVAC Water Circuits?

Chemical dosing involves injecting specific chemicals—such as corrosion inhibitors, biocides, or scale inhibitors—into an HVAC water loop. This process helps maintain water quality by controlling biofilm, corrosion, and scale. Precise monitoring and control are crucial to ensure effective treatment while avoiding chemical overuse or underuse, which can lead to equipment damage or microbial growth.

What Does BSRIA Guidance Say About Water Treatment?

BSRIA (Building Services Research and Information Association) provides guidance on best practices for water treatment in building services, covering system design, maintenance, chemical dosing, and filtration methods. BSRIA emphasizes regular testing, proper commissioning, and ongoing monitoring to ensure HVAC and domestic water systems remain efficient, safe, and compliant with health and safety regulations.

What Does The HSE Say About Legionella Control?

Legionella control often involves a multi-barrier approach, including temperature control (keeping hot water hot and cold water cold), UV disinfection, filtration, chemical biocides (such as chlorine dioxide), and regular system flushing. A comprehensive Legionella Risk Assessment, aligned with HSE (Health & Safety Executive) guidelines, can determine the best combination of technologies and operational measures for each facility.

The Health and Safety Executive (HSE) provides comprehensive guidance to mitigate the risk of Legionella bacteria in public buildings, primarily through the Approved Code of Practice (ACoP) L8 and the associated technical guidance HSG274

What Role Does Ion Exchange Play in Industrial Process Water Treatment?

Ion exchange is commonly used to remove dissolved ions (like hardness, heavy metals, or specific contaminants) from industrial process water. Resin beads attract and bind target ions, often swapping them with more benign ions (e.g., sodium). This process ensures consistent water quality, prevents scale and corrosion, and can be customised with different resin types for specific contaminants.

Can Rainwater Harvesting or Borehole Water Be Combined with Other Treatment Technologies?

Absolutely. Rainwater harvesting and borehole water can be combined with UV disinfection, chemical dosing, filtration, and ion exchange processes to achieve required water quality levels. Depending on the source and intended use, it may be necessary to pre-treat the water before it enters an HVAC system or potable supply to meet regulatory standards and protect equipment from scale or microbiological issues.

How Do I Choose the Right Water Treatment System for My Building?

When selecting a water treatment system, consider:

Type of water source (municipal, borehole, rainwater).
Usage scenario (potable, cooling towers, boilers, industrial processes).
Local regulations and BSRIA or HSE guidelines.
Maintenance requirements and lifecycle costs.
Sustainability goals and environmental impact.
Consulting with an experienced water treatment specialist can help you customise the best solution for performance, cost, and compliance.

Where Can I Learn More About Aevira’s Water Treatment Solutions?

You can visit our About Us page to explore our 10+ years of industry experience and read more about our expertise in HVAC systems, data centres, and potable water treatment. You can also browse our e-commerce platform for staple water treatment products or contact us directly to discuss more advanced technologies that may be suited to your specific needs.

Is ClO₂Sure safe for hospital use?

Yes. Being PT5-listed means it’s authorised for drinking water even for vulnerable populations.

Does ClO₂Sure handle high organic load?

Absolutely. ClO₂Sure’s oxidative power and equilibrium design make it highly effective where organic matter is present, crucial for biofilm control.

What about chlorite and chlorate by-products?

Traditional chlorine dioxide systems can produce high levels of chlorite and chlorate, which must be carefully managed for compliance. ClO₂Sure’s equilibrium-based chemistry ensures minimal by-product generation, making it safer for potable water applications.

Can ClO₂Sure fully replace standard Chlorine (Cl) or Chlorine Dioxide (ClO₂) dosing?

Yes, ClO₂Sure can fully replace traditional chlorine (Cl) and conventional chlorine dioxide (ClO₂) dosing, offering a safer, more efficient, and low-maintenance alternative. Unlike standard chlorine dosing—such as sodium hypochlorite—ClO₂Sure delivers equal or superior microbial control at lower concentrations, reducing corrosion risks, chemical consumption, and by-product formation.

Can ClO₂Sure replace conventional Chlorine Dioxide (ClO₂) Systems?

Standard ClO₂ dosing typically involves two-part precursor systems that require precise pH control and controlled reaction conditions to generate chlorine dioxide gas. This can introduce handling risks and operational complexity. ClO₂Sure simplifies the process by:

Eliminating the need for on-site ClO₂ generation
Providing a ready-to-use single-component ClO₂ solution
Maintaining active ClO₂ levels for longer durations

This makes ClO₂Sure an ideal drop-in replacement for both traditional chlorine and two-part chlorine dioxide dosing in applications such as:
✔️ Cooling towers
✔️ Potable water systems
✔️ Legionella control
✔️ Biofilm removal in industrial & commercial buildings

Can ClO₂Sure fully replace standard Chlorine (Cl) or Chlorine Dioxide (ClO₂) dosing?

What is UVT and Why is it Important in UV Water Treatment?

Ultraviolet Transmittance (UVT) is a critical parameter in UV water treatment, measuring how much ultraviolet (UV) light passes through water. Expressed as a percentage, UVT (%) indicates the water’s ability to transmit UV energy at 254 nm, the wavelength most effective for disinfection and advanced oxidation (AOP). High UVT means fewer contaminants absorbing UV light, leading to better pathogen inactivation and water treatment efficiency.

What is UVT and Why is it Important in UV Water Treatment?

How Does UVT Affect UV Disinfection System Performance?

The effectiveness of a UV disinfection system depends on UV dose, which is influenced by UV intensity, exposure time, and UVT. Low UVT levels indicate the presence of organic matter, turbidity, iron, or other impurities that absorb UV light, reducing germicidal efficiency. Maintaining optimal UVT levels ensures consistent microbial inactivation, meeting regulatory standards for drinking water, wastewater, and industrial water treatment.

What is a Good UVT Level for Effective UV Water Treatment?

Drinking water & ultrapure water: >90% UVT for maximum disinfection
Municipal & industrial wastewater: 60-80% UVT, requiring higher UV doses
Process & reuse water: Varies based on application, often requiring pre-treatment

How Can I Improve UVT for Better UV Disinfection Performance?

If UVT is low, pre-treatment methods such as filtration, carbon adsorption, coagulation, or advanced oxidation (AOP) processes can improve clarity and remove UV-absorbing compounds. Proper UV system maintenance and routine UVT monitoring ensure optimal performance in UV sterilisation, water reuse, and high-purity water applications.

Why is UVT Measurement Important for UV System Sizing?

UVT analysis helps determine the correct UV reactor size and UV dose requirements for specific water conditions. UV systems are designed based on UV dose-response curves, meaning an accurate UVT measurement ensures reliable pathogen inactivation and compliance with industry standards such as NSF, USEPA, and WHO guidelines for UV water disinfection.