Frequently Asked Questions

Frequently Asked Questions

Please check the list below for answers to some of our frequently asked questions.

  • Why do I need odour control in a commercial kitchen?

    Commercial kitchens create a mixture of grease, odour and smoke depending on what is being cooked. The odour can cause a nuisance to neighbours and the general public leading to Environmental Health Officer (EHO) intervention. In addition, grease which gets into the ductwork can cause a fire risk. An effective grease and odour control solution can stop this happening.

  • What is air flow rate?

    Flow rate is the volume of air which passes per unit time. This is generally measured in metres cubed per second (m³/s) and can also be expressed as metre cubed per hour, litres per second or CFM. To convert between these different units, click here.

  • What is an extraction / discharge point in commercial kitchen ventilation?

    The last phase of the extract system. The point at which the kitchen extraction air is discharged to atmosphere. Extraction below the tallest building within 20 meters is classed as low-level discharge, and above this is high level discharge. At most low-level discharge points odour will likely cause a nuisance unless treated.

  • What is ozone?

    Ozone (O3) is a gas produced from oxygen (O2) present in air. It can be produced by plasma discharge or UV light and it is known for its powerful odour and infection control properties.

  • What is ozone injection?

    This is where ozone is released directly into the kitchen ventilation system to act on kitchen odour. To learn more about the Xtract range of ozone injection units, click here.

  • What is the contact time for ozone?

    Contact time or dwell time is a minimum of two seconds. This is to allow the ozone to act on odours. Linear velocity and duct length are variables to consider when calculating dwell time – please contact our team for more information.

  • What is the difference between ozone injection and UVC in kitchen ventilation?

    For low to moderate levels of odour ozone injection is suitable. From moderate to high to very high levels of odour and grease control a Techniclean UV-C is more appropriate. Contact our team for more information.

  • Is ozone safe?

    For kitchen grease and odour control, ozone is released into the extraction system and eventually into the atmosphere at the discharge point. At this time ozone levels are safe because it is converted back into oxygen when it reacts with grease, odour and any humidity in the extraction air. It is also diluted as it leaves the ventilation system. For low level discharge, activated carbon filters are used to control any residual ozone.

  • What is linear velocity and how do I calculate it?

    Linear velocity is the speed at which air travels through the extraction system and is measured in metres per second. This can be derived from the volume flow rate (m3/s) divided by the duct area (m2).

  • Do you do commercial kitchen duct cleaning?

    Plasma Clean equipment is designed to stop grease getting into the extraction system in the first place and many of our products leave extraction ductwork virtually grease free. This results in less duct cleaning and dramatically lowers maintenance costs. If, however your system requires duct cleaning we have a national network of TR/19 approved partners to offer this service. Contact us for further information.

  • What do ESP’s do?

    Electrostatic Precipitators or ESP’s remove grease and smoke particles from commercial kitchen extraction systems. ESP’s start by ionising grease and smoke particles as they travel over ionising electrodes. The particles become electrically charged, these then attract to the collector cells which hold and drop the particles into the drip pan. Plasma Clean ESP’s have a large drip pan and can be fitted with a drain. We can also offer a combined ESP-UV for total grease, smoke and odour control in your commercial kitchen.


  • What does activated carbon do?

    Activated carbon, also called activated charcoal, is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption or chemical reactions. In Plasma Clean systems, we mainly use activated carbon filters to remove any residual ozone before it is extracted to the outside. This is important when the extraction point is at low level, is close to an open window or near to an air intake louvre.

  • Can you help me with a DEFRA odour assessment?

    Yes. Environmental Health & Planning Officers from Local Authorities often refer to DEFRA 2005 & 2010: Guidance on the Control of Odour & Noise from Commercial Kitchen Exhaust Systems. These guidelines have now been withdrawn and are in the process of being updated by the Building and Engineering Services Association (BESA). Whilst a new standard is being prepared by BESA, Plasma Clean recommends following the guidelines of DEFRA 2005 & 2010, in conjunction with other industry guidelines such as the BESA 2018 edition of DW/172 ‘Specification for Kitchen Ventilation Systems’ (Section 24 is relevant for Pollution Control). Other good practice guidelines include TR/19 which covers the internal cleanliness of ventilation systems. The use of Plasma Clean equipment tackles grease and odour control to keep the ductwork clean and the extraction air odour free and in compliance with TR/19, DW/172 and DEFRA 2005 & 2010.

  • Can you help with grease odour and smoke control problems?

    Plasma Clean are the specialists for grease, odour and smoke solutions. We provide systems that blend cutting-edge technology with the best of traditional techniques. To read more about us, click here.

  • What if space is limited in the kitchen?

    Not a problem. We have a unique range of compact products with small footprint so they are easy to install.

    Our ESP Lite is designed for grease and smoke control in smaller commercial kitchens where space is restricted and flow rates are low.

    The ESP Lite can be used on its own or in combination with the Techniclean Mini for the control of grease, smoke and gaseous odours where space is limited.

    To read more about what you can do if space is limited in the commercial kitchen, click here.

  • Can your equipment be retrofitted?

    Plasma Clean Coil Filters,our Xtract Ozone Injection range and Techniclean Mini system are ideal retrofit solutions. Call our team for more information.

  • Will the equipment affect the existing fan?

    All Plasma Clean equipment is designed to have the least impact on fan power. Please ensure that your fan is capable of handling any additional load in the extraction system by contacting your installer.

  • Are there any cost savings if I install Plasma Clean equipment?

    Our products have the highest efficiency and the lowest pressure drop. This will dramatically reduce duct clean costs and also fan maintenance costs. In order to maximise energy efficiency, we offer combine air flow interlocks to ensure that the equipment stays on only when air flow is detected in the kitchen extraction canopy or ductwork.

  • How much power do your products need?

    All of our products are designed to utilise the lowest possible power whilst operating at the highest efficiency. Power ratings for each individual product are shown on our product datasheets found on our resources page.

  • What does Plasma Clean need to know to offer the best solution?

    We need to know only five things to offer you the best solution:

    1. Volume flow rate
    2. Type of cooking
    3. Discharge level
    4. Length of ductwork
    5. System drawings

    We may need further information, but this will get us started. For more information and to fill in an interactive form and get a quick quote within 24 hours, please click here.


  • Does Plasma Clean supply a warranty?

    Plasma Clean equipment carries a two-year parts only warranty and extended warranty by taking out a Plasma Clean Plan. If you want to know more about this, please click here.

  • Does Plasma Clean provide unit servicing?

    Our nationwide network of approved specialists provides seamless customer care from specification to installation to service.

    Give yourself peace of mind with a Plasma Clean service plan. It will keep your systems performing at their peak. You can choose from a bespoke 1,3- or 5-year plan designed to cover both planned preventative maintenance and specialist maintenance and repair. To know more about our service, please click here.

  • Do you ship internationally?

    Yes. We work across the UK and beyond with international agents. They can help specify and supply our products. Please enquire and we can put you in touch with a local representative.

Some of our Clients