HVAC. Hygiene. abstract. Mr Jeremy Stamkos

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1 NADCA Mr Jeremy Stamkos Managing Director, Enviroair Pty Ltd Certified Air Systems Cleaning Specialist abstract This article has been written to assist those responsible for the maintenance and operation of Heating Ventilation & Air Conditioning Systems (HVAC) better understand of the importance and need for Ventilation. Due to the internal conditions of a buildings ventilation systems usually being out of sight, out of mind, much of the Air Duct Cleaning undertaken in our Facilities is done as a reactive measure to either complaints, contamination fallout or airflow restrictions. There are many issues that may arise from contamination build up in a building s Heating, Ventilation and Air Conditioning Systems. This article endeavours to highlight some of these issues, address possible ramifications of unhygienic HVAC systems and explain how those responsible may take a proactive approach to HVAC system. Indoor Air Quality (IAQ) is a phrase that s becoming ever increasingly well known amongst many building owners, engineers, facility managers, consultants and other building maintenance personnel. To many Facility Managers, the subject of indoor air quality is a bane, usually warranted due to persistent service providers or consultants eager to exploit the subject and peddle their goods or services. Unsubstantiated claims, biased reporting and scare mongering sensationalism are a few of the reasons that such scepticism is often evident in the thinking of many facilities managers. Although a certain degree of scepticism is understandable, there has been much qualified research undertaken by agencies such as the US Environmental Protection Agency, the World Health Organisation and other leading independent researchers into the importance and need for acceptable Indoor Air Quality. Throughout much of today s published studies and reports on Indoor Air Quality, it seems that one of the major but most commonly overlooked contributors to poor IAQ is a building s Heating, Ventilation & Air Conditioning (HVAC) Systems. Although many common indoor air pollutants may be generated by activities or sources from within the confines of the building, many are drawn into or created by the HVAC Systems themselves. As the majority of indoor air is recirculated through the buildings Air Conditioning Systems, the majority of contaminates found within enters via the Return Air Component. As well as the Return Air System, a significant amount of pollutants and other contamination may enter a building s ventilation systems via the Outside Air Intake or even be generated from the HVAC system itself. These contaminates that either pass through or settle within the buildings HVAC systems can significantly impact a building s Indoor Air Quality and have many detrimental and costly ramifications. In many buildings, poor ventilation hygiene alone is able to lead to Sick Building Syndrome and inturn Building Related Illnesses. Article as published in The Australian Hospital Engineer Vol 26, Number 2 Autumn 2003

2 Infiltration As airborne particles and other contaminates are constantly entering the buildings ventilation systems, it is extremely important to have adequate filtration in place to minimize infiltration of these contaminates into the occupied areas of the building. Most Outside Air and Return Air components of HVAC systems have filtration systems in place to help reduce the amount of pollutants from outside and recirculated air entering the system. Unless the filters are high efficiency such as HEPA (typically found in critical areas of Healthcare facilities and clean rooms), they will still allow some extent of contamination to pass through. The amount of particulate and other contaminates that manage to pass through standard type filtration systems may seem insignificant however overtime, this may lead to considerable and possibly hazardous levels of contamination accumulating downstream of the filters. Incorrectly installed or damaged filters will allow bypass of unfiltered air into the HVAC system which may also lead to significant levels of contamination build-up within the system. To this end it is prudent to ensure the filtration contractor or personnel responsible for the maintenance of the filters are competent and there is a filter maintenance program in operation. For the most part, proper maintenance of the filtration system will help maintain overall hygiene of the system and prolong or prevent altogether costly remedial works. Types of Contamination There are literally thousands of types of contaminates commonly found in HVAC systems ranging from general nuisance type dusts to pathogenic moulds and fungi. Other types of contaminates found in HVAC systems may be lint, carpet fibres, building rubble, construction dust, spores, pollen, bacteria, asbestos, rust, fibreglass, human skin and hair. In most cases, the contamination commonly found within HVAC systems is introduced from external sources such as nuisance dust generated from inside the building or fine dirt from outside the building. There are however situations where the source of the contamination may be generated from within the HVAC system itself. Delaminating foil faced insulation and deteriorating foam seals are common sources of contamination found in ventilation systems. Over time, some of these materials may deteriorate, break down or delaminate and end up being blown out through the vents and into the occupied areas that the system services. This level of deterioration generally only happens when the components of the system have been subject to adverse conditions such as prolonged extreme temperatures, excessive water activity or damage inadvertently caused by tradespeople working on or near the system. Of particular concern are HVAC systems that harbour significant levels of microbial spores and fungal growth. Significant proliferation or presence of mould within HVAC systems has the capacity to cause major operational deficiencies, excessive energy consumption, building related illnesses and even costly property remediation. As many of these common contaminates may lead to many serious concerns, it is crucial that the person/s responsible for the maintenance of the building s HVAC systems are aware of the internal cleanliness levels of the systems.

3 Fallout When the accumulation of contaminates within a HVAC system begin to spill out into the occupied areas within a building it is often referred to as Fallout for obvious reasons. Dust, debris or any other contaminates falling out of a HVAC system s vents or grilles is a sure way to raise OH&S concerns amongst the building occupants. Building occupants will usually react in different ways to fallout depending on the amount of fallout, the nature of the activities in the area, individual personalities and their perceived health risk from the fallout. If one thing is almost certain when building occupants experience fallout, is that the property managers or those responsible for the systems maintenance will continually be hounded until the problem is rectified or goes away. Many times when this happens, those responsible for the maintenance of the HVAC system are not entirely sure what steps to take and will simply install a piece of temporary filter material above the problematic vent or grille hoping that will quell the problem. Temporary placement of filters above the problematic vent/s may be a very useful measure to protect the occupied area and it s occupants until the cause of the fallout is identified and remedial action can be undertaken. However, when temporary filters are installed above the vents they are often forgotten about and eventually end up heavily loaded with contamination restricting airflows and compromising the operating efficiency of the system. Decreased System Efficiencies << Delaminated Insulation in a Return Air Duct Heavy build up of contaminates within a HVAC system has the capacity to severely compromise operational performance and dramatically increase the systems energy consumption. When airflow through the system is restricted due to contamination build up, the system will use more energy to provide less conditioned air into the areas it services. The most common components of a HVAC system to accumulate significant contamination and restrict airflows are filtration systems, Heating and Cooling Coils. Heating and cooling coils may become fouled with all types of contamination including dust, insulation and microbial growth. Even low levels of contamination on cooling coils may help in providing the ideal environment for microbial proliferation. Coil fouling is not always visibly detectable as the face or air on side of the coil may have had a cosmetic clean with the bulk of the air restricting build up being deeper within the coil. Severe coil fouling will dramatically reduce the airflow through a system and in some cases airflows have been reduced to almost nil. As well as increased operational costs, there are also comfort issues that may arise from the system not effectively delivering conditioned air to the occupied areas. Regular inspections, coil cleaning and proper filter maintenance all help to keep HVAC systems operating efficiently.

4 Determining HVAC System Cleanliness The question is often asked, How does one determine when a HVAC system requires cleaning? Unfortunately there are not many helpful guidelines or standards in Australia for minimum levels of acceptable cleanliness within HVAC systems. What little standards and legislation there is that relates to this subject is not well developed and is somewhat open to interpretation. Until such time that clear standards, guidelines and legislation are developed in Australia, there are some excellent international standards that can offer Facilities Managers best practice guidelines for HVAC system hygiene. One such standard is ACR 2002, Assessment, Cleaning & Restoration of HVAC Systems developed by the National Air Duct Cleaners Association (NADCA) U.S.A. This standard defines minimal acceptable levels of HVAC cleanliness and specifies periodic inspection intervals for several building classifications. The standard states that HVAC systems should be operated in a clean condition. If significant accumulations of contaminates or debris are visually observed within the HVAC system, then cleaning is necessary. Also; If the HVAC system discharges visible particulate into the occupied space then cleaning is necessary. Going one step further than basic visual assessment, the ACR 2002 Standard states that the acceptable level of cleanliness may also be determined by the NADCA Vacuum Test. The test is done by using an air sampling pump and filter medium to collect a sample of the settled dust on the internal surfaces of the HVAC system. Section of the ACR 2002 says that for a HVAC system To be considered clean by the NADCA Vacuum Test, the net weight of the debris collected on the filter media shall not exceed 0.75 mg/100 cm2. The decision as to wether or not a HVAC system requires cleaning may be determined by many factors such as the number of complaints received, nature/type of contamination, possible OH&S risk, duty of care, litigation exposure, financial position, the policy of the organisation etc. A proactive approach to HVAC System Regular inspections of the internal components of a building s HVAC systems will help identify components or systems that may be harbouring significant contamination levels. During any inspection, particular attention should be given to areas in the systems where moisture may be found such as Outside Air Intakes, Cooling Coils, Condensate Drain Pans and Humidifiers. These are the areas that are most likely to provide adequate conditions for microbial proliferation and should be inspected regularly to ensure they are free from visual fungal growth. Fibreglass Insulation in a Supply Air Duct Although most Facilities do not have HVAC Programs in place that include regular inspection and cleaning programs, an ever-increasingly number of Australia s prudent Facility Managers are now making concerted efforts to maintain hygienic HVAC systems and are employing specialist service providers to assist them in their endeavours

5 Choosing the right qualified contractors to assist in the identification of and remediation of contaminated HVAC systems may sometimes prove difficult. When employing the services of any Indoor Air Quality consultant or HVAC cleaning contractor, it is crucial that the contracted party has adequate experience and knowledge in conducting these types of services in even the most sensitive environments. One should always endeavour to seek out contractors or service providers who are able to provide evidence of related formal training and qualifications. With heightened awareness on Indoor Air Quality, Green House gas emissions and workplace health and safety, today s Facilities Managers are faced with added pressures to operate and manage the work environment to a much higher standard than ever before. Proper HVAC hygiene will help insure against many of the negative ramifications that contamination harboured within the systems may result in. Fungal Growth in Aluminium Flexiduct Toxic Mould Growing on Internal Insulation About the author: Mr Jeremy Stamkos is the Managing Director of Enviroair Pty Ltd. Enviroair Pty Ltd is a company that has been specializing in the decontamination and remediation of Commercial and Industrial HVAC Systems since early Mr Stamkos has been directly involved with the company since its conception and in 2001, he became the Managing Director. Many years of direct employment within the HVAC Cleaning Industry as a Technician, Supervisor, Projects Manager, Operations Manager and now Managing Director ensures that Mr Stamkos vast experience and qualifications in the industry are unsurpassed within Australia and even the Australasian Region. Reference: ACR 2002 Section The NADCA USA ACR 2002 Standard is available to purchase on the web For further information, you can contact Enviroair on or solutions@enviroair.com.au Article as published in The Australian Hospital Engineer Vol 26, Number 2 Autumn 2003