Top 5 Reasons for Odour Control System Failures

Odour Control Unit

Today’s odour control systems are engineered intricately to maximise removal rates from high air flows with efficient, compact designs.

System failures are primarily caused by engineering and design issues and odour control systems’ incorrect sizing and specification.

This article will explore the top five reasons for odour control system failures.

Specifying solutions based on guesswork

When odour control decisions are based on guesswork, this often results in incorrectly specified odour control systems. No two sites are the same, so past experiences and best practices are no guarantee of success.

When odour control systems are specified, decisions must be made based on data, samples, and research. We need to understand the nature of odours, including their type, offensiveness, frequency and intensity.

Working with an odour control expert like OSIL is crucial to collecting the correct data and specifying and designing the right solutions.

Incorrect system configuration

In multi-stage treatment systems, upstream and downstream odour control processes cleanse the air for the following process. The order and configuration of these processes are essential to maximising performance and uptime.

For example, in a multi-stage treatment system consisting of a biofilter and a wet scrubber, the wet scrubber should come first to remove inorganic contaminants that would damage the microorganisms in the biofilter. Dry media is generally a final polishing stage or an initial polishing stage with a venturi scrubber to remove dust.

Limescale build-up in wet scrubbers

Limescale build-up is a common problem in wet scrubbers. It decreases performance, reduces operational capacity and breaks machines when the build-up is thick. Unfortunately, limescale build-up is not preventable, but it is manageable.

Cleaning is easy; all you do is run a biodegradable cleaning agent through the system following a set number of cycles. Using water softeners during cycles will reduce limescale build-up, helping the cleaning agent do its job.

Incorrect microbiology in biological systems 

Biological odour control systems are self-contained and self-sufficient. The lead cause of failures in biological systems is incorrect microbiology – we need an environment where microorganisms can survive and thrive.

When designing biological systems, we partner with leading academia covering key microbiological aspects: selecting and cultivating tailored bacteria and specialist seeding and population health monitoring.

A worst-case scenario for a poorly designed biomass is a complete failure, i.e. the microorganisms don’t survive. This can happen because the air flowing through the filter is toxic to the microorganisms, or the organic compounds are not assimilated, so the microorganisms starve and wither away.

Not following recommended maintenance cycles 

Odour control systems need scheduled service and maintenance cycles to prevent reactive maintenance and reduce costs and disruption.

A lack of maintenance, such as failing to clean and lubricate parts and not replacing filters at recommended intervals, invites problems. Without maintenance, odour control systems will be less efficient and could suffer breakdowns.

Here are a few examples of maintenance:

  • Biological systems – Check media health, irrigation inspection, including spray pattern and nozzles.
  • Chemical scrubbers – Check media quality, look for evidence of calcium build-up, traces of sludge build-up.

Find out more

Speak to one of our odour control experts today to find out more about how we help keep odour control systems working at their best.

How Odour Control Depends on Service and Maintenance

Odour control systems require regular service and maintenance to prevent equipment failures and assure system performance. 

Service and maintenance are crucial parts of an odour control system’s life cycle because they manage wear and maximise lifespan.

It’s important to note that all odour control systems, biological or chemical, have specific needs that can only be managed with service and maintenance, so their uptime and performance depend on S&M.

Examples of requirements

With chemical scrubbers, a build-up of limescale (calcium carbonate) can block and damage the system. Water softeners must be used to manage limescale, with pipes and components (including tanks) cleaned extensively during maintenance.

With dry media filters (activated carbon and impregnated carbon, oxidising alumina media, and hybrid, multi-media filters), old media needs replacing with new media when spent, so routine maintenance is necessary to assure performance.

With biological scrubbers (both biotrickling and biofilter types), the microbiology of the biomass can get knocked out of whack if the biofilter isn’t managed. Microorganisms in the filter need to be fed the right odorous substances to survive, so changes inlet stream can directly affect removal efficiency and biomass health.

Assuring total system performance

When an odour control system uses a variety of technologies/processes to remove different odorous compounds in a cycle, we have to consider the system as a single unit, where the performance of one technology affects the other.

For example, a wet scrubber might remove inorganic compounds from  the contaminated air streams to prepare them for biofiltration, which will remove organic, biodegradable compounds. Dry media can then be used as a final polishing stage.

Consider these odour control systems like links in a chain. Service and maintenance keep each link in optimal condition, so the systems function as one. If one fails, the whole cycle is broken, causing costly downtime.

Managing carbon emissions

Another important reason for service and maintenance in odour control is reducing total carbon emissions from odour control processes.

Inefficiencies brought about by a lack of maintenance, like failing to clean and lubricate parts and not replacing filters at recommended intervals, can significantly increase  emissions from operations. Systems could use more power, or you might have breakdowns that create an increase in emissions.  

Do you need help with S&M?

We recommend monthly checks for all odour control systems. During a monthly health check, a visual inspection of the plant and associated equipment will be performed, and physical tests will be conducted to measure and monitor performance.

Here are a few examples of maintenance:

  • Biological systems – Check media health, irrigation inspection, including spray pattern and nozzles.
  • Chemical scrubbers – Check media quality, look for evidence of calcium build-up, traces of sludge build-up.

Preventive maintenance is necessary to prevent larger problems, and it is cheaper than repairing damaged equipment. Every business should have a service and maintenance plan, and we can help if you need one.  

OSIL offers a full range of service and maintenance packages to suit all requirements and budgets. Gold, Silver & Bronze packages are available, and we service and maintain our systems and equipment from other supplies.

Feel free to call us on (0) 1543 506855 for a chat about how we can help you.

Why optimise your service and maintenance strategy?


Service and maintenance is all about making sure things work properly, but there’s a lot more to it than simply scheduling appointments.

Companies that are serious about their air pollution, ventilation and odour control systems need an optimised service and maintenance strategy.

What is a service and maintenance strategy? It’s a strategy that defines your system’s operational requirements and how these requirements can be met with service and maintenance. It is not a static strategy, but an adaptive strategy that changes when you identify improvements and new requirements.

Some companies will buy engineered equipment, put routine service and maintenance dates into their calendar and forget about it. This is a missed opportunity to optimise service and maintenance to achieve real business benefits.

Structure and schedule

Optimised service and maintenance strategies do away with “tick and flick” style routine maintenance. The risk of “tick and flick” maintenance is not identifying future problems and inspecting hardware at only a minimum level.  

Rather than promote bare minimum maintenance, more intensive checks can be deployed to catch problems and reduce the need for future, costlier repairs. Consider structuring your maintenance strategy to work at a higher level.

You’ll be able to plan better

By structuring and scheduling your service and maintenance, you’ll be able to plan uptime and downtime perfectly. This is beneficial for your business and customers. You can reduce unplanned maintenance by 90% with a good strategy.  

Operational focus

Some companies are reluctant to take equipment out of service for maintenance. This can end in disaster. What is the point of putting off service and maintenance for a week, if doing so could put the equipment out of action for two weeks?

Without maintenance, you risk even longer downtime and more expensive repairs when something fails. Optimising your service and maintenance strategy to recognise this so your operation is focused on uptime will be a smart decision.

You’ll manage costs better

An optimised service and maintenance strategy will allocate your budget to the right places. You will significantly reduce unplanned maintenance. The cost to maintain equipment will be less because maintenance will be a properly planned routine, not reactive.  

Missed opportunities to improve

The “leave it and forget it” approach to air pollution, ventilation and odour control systems only works when you ignore the fact that technology moves on. These systems get more efficient and better at their jobs with each generation.

An optimised service and maintenance strategy recognises these advancements in technology and deploys them whenever suitable. Engineers should look for opportunities to make systems more energy-efficient and cleaner.

You’ll build knowledge in your systems

Experts have a way of keeping knowledge in their heads, and when they leave, that knowledge goes with them. With an optimised strategy, your engineers will play a lead role in developing maintenance guidelines and best practices for your systems.

Avoid reactive routines that overcompensate

Sometimes, hardware failures cause panic, leading to reactive work that tries to solve problems that don’t exist. The problem here is spending money on unnecessary work and engineers wasting their time doing pointless work.

With an optimised service and maintenance strategy, you will take a deeper look at your systems, hardware, and monitoring practices. You will specify the hardware that is a cause for concern and ensure all non-issues remain non-issues.

Want to find out more about service and maintenance strategy?

Call us today on +44 (0) 1543 506855 to speak with one of our experts.

How to Maintain an Odour Control System

Odour Control System

Service and maintenance is key to ensuring that your odour control system continues to work as intended and is safe to use.

Without service and maintenance, your odour control system will be susceptible to problems like failing components, a build-up of residue (limescale, sludge, etc.) in scrubbers and vessels and electrical and mechanical bugs.

These problems could be disruptive to your operation by causing unscheduled downtime and they could even cause a breakdown. 

It’s also important to note that some odour control systems have serviceable parts. For example, the filters in some odour control systems need cleaning or replacing during routine servicing to maintain optimal system performance.

Service and maintenance is essential to catch disruptive problems early and ensure your odour control systems continue to operate optimally.

Monthly health checks

Monthly health checks

The best way to maintain an odour control system is to have routine service and maintenance health checks. These checks should form part of a planned maintenance schedule that’s designed for your system.  

Health checks involve visual and physical checks of the odour control system extending beyond process plant to all associated equipment. These checks can vary from one system to another depending on the size and complexity of the system.

A monthly health check will generally include:

  • A visual inspection of plant and associated equipment
  • Physical tests, including:
    • Measurement of inlet and outlet odour levels.
    • Measurement of air velocities.
    • Check fans are running correctly, drive belts are ok, grease bearings, check hours run meters and other mechanical components.
    • Check ducting, check for any UV degradation, check the supports are ok, check the dampers are operating correctly, drain condensate.
    • Check and recalibrate instrumentation.
  • Biological systems – Check media health, irrigation inspection including spray pattern and nozzles.
  • Chemical scrubbers – Check media quality, look for evidence of calcium build-up, traces of sludge build-up, check chemical dosing system including inspection of pumps, valves, instruments and pipework. Dry media systems – inspect media, carry out media analysis if appropriate.
  • Other checks depending on the system – water softener salt levels, chemical storage and dosing equipment.

Examples of maintenance

Example of Maintenance

Multi-stage odour control systems should be inspected once per month and smaller or more basic systems may be inspected quarterly or every six months depending on your needs.

Mechanical components like fan drive belts are serviceable parts that should be replaced periodically when worn. Filters should also be cleaned and replaced when spent, spray nozzles should be checked and cleaned regularly, and scrubbers and other vessels should be cleaned when required.

Pipework and ductwork may need replacing or resealing over time. Vessels may corrode or become contaminated and need replacing or deep cleaning. Scrubbers may have a build-up of sludge that needs removing.

You may need to replace or optimise your bio-media. Biological systems may need biologically rebalancing to promote a healthy biomass. You may experience pressure drops in the system or abnormalities if the system is not maintained correctly.

You may detect odour coming from the system. This is often the first sign that there’s something wrong. This could be caused by a blockage, media deterioration, a leak, chemical dosing malfunction or a problem with the ductwork.  

At OSIL, we believe that service and maintenance is essential for every odour control system, so we make maintaining your odour control system easy with Gold, Silver & Bronze packages. These packages can cover everything from scheduled maintenance to call outs, so that your odour control system always runs at its best.

Want to know more about odour control system maintenance? Feel free to call us on (0) 1543 506855 for a chat about how we can help you.