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Shepherd Filters: Why are they the solution for me? November 6, 2019


The purpose of a kitchen grease filter is to be the exhaust system’s first line of defense, preventing grease accumulation and the subsequent risk of fire.  Read on to discover six problems with standard metal grease filters and, more importantly, the six solutions Shepherd Filters provide.


Shepherd Filters protect the exhaust system above kitchen staff frying chicken


Problem #1: Too much grease passing through the filter

Standard metal filters only stop between 20-40% of the airborne grease from entering the exhaust system.  This results in a build-up of grease in the hood, duct and fan, meaning frequent cleans are an ongoing cost.


Solution #1: Capture up to 90% of the grease inside your filter

Shepherd Filters are 100% natural wool, providing the best solution by capturing up to an impressive 98% of airborne grease before it enters your kitchen exhaust.  This leaves you with a clean system, 365 days of the year.

Special stainless-steel Shepherd Filter frames are easy to use and come with the guarantee that they are:

  • UL1046 flame barrier tested
  • Airflow tested & certified; and
  • HACCP approved



Problem #2: Cleaning kitchen grease filters

Cleaning grease filters is an ongoing problem that can be expensive, disruptive and difficult.

Using a filter exchange company:

  • Filters are sometimes cleaned sooner than needed, or alternatively, left too long.
  • Exchange companies can be disruptive if they arrive during service times.
  • Sometimes kitchen staff will still have to spend additional time washing filters in between exchanges.

In-house cleaning:

  • Time consuming and high labour cost.
  • Excess water and unnecessary exposure to unpleasant chemicals can be a waste and also very costly.
  • Environmentally unfriendly.
  • Potential cause of dishwasher breakdowns.
  • Not always cleaned thoroughly.


Solution #2:  Disposable woollen grease filters

In comparison, Shepherd Filters will save you time and money.  This solution is extremely user-friendly and filters can be changed and disposed of in less than one minute!  Other benefits include:

  • Shepherd Filters are 100% naturally fire-retardant wool.
  • They are 100% biodegradable.
  • This solution allows you to only change the filters that need changing.
  • Disruptions are minimised as filters can be changed in the morning before turning your equipment on, or in the evening after the final clean down.



Problem #3: Difficulties with canopy and hood cleaning

IRHACE HVAC Hygiene Best Practise Guideline requires a hood and its exhaust plenum to be checked at least monthly for excessive grease accumulation.  It also requires the hood and plenum to be cleaned at least annually.  This is costly, messy and disruptive, and the grease can build-up in a system as fast as one month.  Any excessive grease accumulation will increase fire risk, and this can happen very quickly between cleans.  Furthermore, it is important to check the thoroughness of the clean as responsibility can still be placed on the restaurant.  Clauses or fine print on certificates issued by cleaning contractors can cause insurance companies to void claims in event of a fire.  Shepherd Filters frequently inspect kitchen exhausts after scheduled cleans and find:

  • Sub-standard cleaning has occurred; or
  • The entire system was not cleaned due to poor access.

Here are real-life examples, just days after a clean:

evidence of incomplete duct clean

READ: Are You Risking the Life of Your Kitchen? 18 examples of fake duct cleans


Solution #3: Reduced canopy and hood solution 

Shepherd Filters stop you guessing when your system is dirty.  A massive saving occurs in the reduced hood, canopy and duct cleaning as Shepherd Filters protect a clean system.  All that is required is a simple mini spot inspection and clean when scheduled. The images below prove how drastically Shepherd Filters reduce grease accumulation inside a hood.

L: hood interior after 4 months with Shepherd Filters; R: hood interior after 2 years with Shepherd Filters
L: hood interior after 4 months with Shepherd Filters; R: hood interior after 2 years with Shepherd Filters


Problem #4: grease in filter gutters

Cleaning filter gutters is an ongoing and messy task that is often overlooked or only partially completed by filter exchange companies.  IRHACE HVAC guidelines requires that gutters are checked monthly.  Left untouched, these also pose a fire risk.


Solution #4: Reduced grease in filter gutters

Shepherd Filters trap the grease in the wool, reducing the amount of grease draining into the gutters.  This reduces labour costs and fire risks.  Below are true examples:

Grease accumulation in gutters with and without Shepherd Filters


Problem #5: Grease build-up in fans and on roofs

Grease can build up very quickly on a fan and easily go unnoticed.  This affects airflow and causes unbalanced fans and excessive loading, which can all bring about premature failure of the fan.

Recently, Shepherd Filters had a client that discovered his kitchen exhaust system had never been cleaned correctly, causing it to fail.  The fan was replaced, and the entire system was cleaned thoroughly.  Shutting the restaurant to do this resulted in a loss of income greater than $30,000 and this was not covered by insurance. 


Evidence of grease build-up on fan and roof
Evidence of grease build-up on fan and roof


Solution #5: A clean fan and roof

Shepherd Filters will capture up to 98% of airborne grease before it enters the exhaust system.  This will not only keep your fan cleaner, but also extend its lifespan and improve the airflow throughout the entire system.  Reduced grease build-up also means a reduction in the frequency of rooftop and equipment cleans, again saving you money.


Problem #6: Fire risk

Although insurance exists for once a fire occurs, it can surely be agreed that preventing a fire is the overall objective for everyone.  Due to substandard cleans or grease build-up between times, there can be potential fire risk just weeks after a duct clean.  Kitchen exhaust fires caused by a build-up of grease lead to insurance companies rejecting rebuild claims and never covering loss of income.  Many restaurants never recover from a fire, due to the costs of letting staff go, loss of income and fixing the damage.


Solution #6: Reduced fire risk

Shepherd Filters greatly reduce the grease build-up between cleans.  This reduces your risk of fire spreading throughout the system, and allows any fire suppression systems to function correctly.




About the Author:

Saskia Prestidge is a content marketer, passionate about critical hygiene in the food industry. 

Amazed by the team’s extensive experience, Saskia is on a mission to squeeze the knowledge from their heads and share it with the food industry. 

Saskia would love to hear from you.  Find her at saskia@presco.co.nz




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