If duct cleaning

If duct cleaning is determined to be the best option: 1. Hire a duct cleaning contractor who is a member in good standing of the National Air Duct Cleaning Association. Duct cleaning companies must meet strict requirements to become NADCA members. Among those requirements, all NADCA Members must have certified Air System Cleaning Specialists (ASCS) on staff, who have taken and passed the NADCA Certification Examination. 2. PROTECT building occupants during and after duct cleaning: • Place a filter over supply and return grills to capture dust when HVAC system is placed back into service after cleaning. • Perform duct cleaning during hours when the building is unoccupied, such as nights and weekends. • Use containment barriers and proper ventilation equipment, such as “negative‐air” machines equipped with high‐efficiency filters. • Avoid the use of biocides and sealants. Even EPA‐registered biocides may pose health risks, including eye, nose, and skin irritation. • No biocides are currently EPA‐registered for use on fiberglass duct board or fiberglass‐lined ducts. Both the EPA and NADCA recommend replacing wet or moldy fiberglass duct material.

High Level

High Level Ventilation Canopy Cleaning
1  Operatives to check all PPE, cleaning equipment and chemicals required for the task. Refer to COSHH assessments supplied for chemicals being used. Operatives to set out all ‘Caution/Warning’ signage required and cordon off cleaning area prior to work commencing.
2  Operatives are reminded that canopies can be fragile or may have loose screws or bolts, seams can be broken and surface dented or misshaped.
3  Operatives to erect access equipment e.g.. stepladder or ladder in the correct and safe manner. Ladders to be erected at the correct angle of 1:4 (75º). If working between 2-6 metres height ladders must be footed or an approved ladder stopper or stabiliser used.
4  Operatives to take care if leaning ladder on to canopy cover, if possible position ladder on to nearest solid surface instead, e.g. wall.
5  Operatives to wear tool belt with all tools attached, this will leave both hands free for climbing and descending ladder or step ladder. Operatives are reminded not to climb above 4 rungs from the tops of ladders or step ladders.
6  Operatives to clean canopy using the correct chemical on a clean cloth  or  ‘Greenie’.

surface or cause

surface or cause panels to fall out of the framework. Ceilings may be badly stained, be old or have poor quality surfaces, therefore do not use any other chemicals other than the chemical stipulated, as this may strip the surface or leave streaky marks. If any panels are damaged or fall out during cleaning immediately inform the Supervisor.
7  Operatives to spray chemical on to an area of approx. 1m2 and allow to soak for a few minutes. Repeat this process in a methodical manner working across the ceiling. Operatives to take care when cleaning false ceilings to clean right up to and including edges of support framework. Note: do not over spray as this will cause streaky marks and drip on to the floor.
8  Operatives to use a clean cloth or ‘Greenie’ (if the surface allows) to wash each area in turn, an extension pole with cloth or ‘Greenie’ fitted may be used if necessary.
9  On completion of cleaning, operatives to dispose of all waste chemicals and materials on site and remove all cleaning equipment, chemicals and signage to company vehicle.
10  Operatives are not to leave the site until authorised by Supervisor.

demand is being

demand is being addressed by firms who market air duct cleaning services. Because barriers to entering the air duct cleaning business are minimal and uniform standards of professional practice have yet to be adopted, anyone with an interest can enter the field. This has permitted firms to spring up with controversial techniques. This is not to say that most duct cleaning businesses are unethical. Companies are seeking the best solutions for each individual home with contamination problems. They are looking for new and better ways to serve a very troubled clientele. The clientele is also wary because little is known about duct cleaning. What is the best source of information for consumers about air duct cleaning? Unfortunately, since there are few or no published papers by independent researchers, most of the information available is from people associated with the air duct cleaning industry. Since air duct cleaning procedures have evolved mostly from trial and error as unique and creative solutions have been sought, there has been considerable confusion in the minds of consumers who fear or who are experiencing indoor air quality problems. Here are some insights gleaned from a publication, Indoor Air Review1. The articles have all been written by people involved with firms specializing in air duct cleaning, filtration, and consulting.

TESTING METHODS AND EQUIPMENT

TESTING METHODS AND EQUIPMENT There are two main methods of testing. The pressurization subtraction method utilizes a pressurization unit (i.e. a high-powered fan set up in a doorway and connected to pressure gauges) to pressurize first the entire space that is heated and/or cooled and then the same space with the duct system blocked off. This method is less accurate than the duct testing method. The duct testing method uses a calibrated fan that gently pressurizes the ducts and measures the airflow through the ducts to indicate total leakage. The duct tester consists of a portable fan with calibrated digital pressure gauges that is connected at the blower compartment of the air handler, or attached to the main return grill. All of the duct registers and grills are temporarily sealed, and the duct tester fan is turned on to pressurize the system. The fan pressure is read from the gauges and converted to an equivalent duct leakage rate in cubic feet per minute (cfm). If the amount of air loss falls outside acceptable limits, sealing will be required to correct the condition. This method of testing is preferred, because it measures low airflow accurately, and simulates what takes place under normal operating conditions.

Calculation of acoustic

Calculation of acoustic power is based on measurement of sound pressure level and reverberation time of the testing room. Because it is necessary to measure the level of sound pressure, a low level of a background noise is an essential requirement to be able to offer the best testing results. To achieve this, the reverberation rooms are isolated from the surroundings by a double wall. The first wall is of a heavy construction, so an optimum isolation is ensured against aerial noise. The second wall (interior of the reverberant rooms) not only improves the isolation by providing more mass to the construction; its design also gives rise to a very wide sound field (an essential condition for the correct calculation of the sound power level from the sound pressure level).
First, an enclosure was built to form the perimeter of the exterior rooms. Then the inner walls of the reverberation rooms were raised to favour the diffusion conditions in the sound field. Between both structures, an acoustic insulation material was installed; see Figure 1.

1000 inhabitants).

1000 inhabitants). Sales in other European countries are less than 0.1 heat pumps per 1000 inhabitants.
In 2001, of the total sales in Europe of 41,000 ground-coupled heat pump systems, 27,000 were installed in Sweden. For the next 3-5 years, market growth rates have been estimated by industry as shown in Table 2.
Table 2: Ground-coupled heat pump market Europe.
Country Sales 2001 Growth, %
Austria 4,800 8 Czech Republic 350 25 Denmark 150 >100 Finland 1,250 10 France 850 10 Germany 3,600 20 Netherlands 400 >25 Norway 650 10 Poland 500 5 Sweden 27,000 6 Switzerland 2,800 6 UK 150 >100