PREVENTION

PREVENTION of duct contamination is KEY to avoiding problems Follow these recommendations to avoid the need for costly duct cleaning: • Perform routine preventive maintenance of HVAC systems, by complying with manufacturer schedules for changing HVAC filters and cleaning coils and other components. • During building renovation, seal ductwork to prevent construction dust and debris from entering the HVAC system. • New ductwork frequently contains oil and debris. Before new ductwork is connected to the air handling system, it should be inspected for cleanliness and cleaned if necessary. • Maintain good housekeeping in occupied spaces. • Ensure that air intakes are located away from contaminant sources. • Consider routine inspections of ductwork. The National Air Duct Cleaning Association (NADCA)’s standard, “Assessment, Cleaning and Restoration of HVAC Systems – ACR 2006,” recommends that HVAC systems be visually inspected for cleanliness at regular intervals, depending on the building use. For healthcare facilities, the standard recommends annual inspections of air handling units, as well as supply and return ductwork

Operatives to rinse

Operatives to rinse off surface of canopy with clean water and polish dry using clean cloths, if necessary use stainless steel polish.
8  On completion of cleaning, operatives to dispose of all waste chemicals and materials on site. Remove all cleaning equipment, chemicals and signage to company vehicle.
9  Operatives are not to leave the site until authorised by Supervisor.
This Method Statement to be used only to underpin a Full Site Specific Method Statement
Ventilated Ceiling & Removable Ceiling Tile 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 prior to work commencing.
2  Operatives to check that any ceiling mounted, vent-axia type fans are turned off and controls isolated.
3  Operatives to secure the work area. Check client has arranged for gas and electric of equipment below is turned off. Ensure client has arranged for all gas pilot lights to be extinguished. Ensure all controls are isolated including air handling equipmen

Cleaning High Level

Cleaning High Level Ducting & Pipes
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 will erect ladders at the correct angle of 1:4 (75º). If working between 2 - 6 metres in height ladders must be footed or an approved ladder stopper or stabiliser used. If working between 6 -9 metres in height ladders must be fitted with approved top and bottom stabilisers unless there is a ladder tie system in place in which case the ladders must be tied off.
3  Operatives will wear a tool belt and ensure that all hand tools are secured to the belt via a lanyard.
4  Operatives will climb ladders using both hands at all times. Do not climb above 4 rungs from the top.
5  Operatives to commence cleaning, keeping one hand on the ladder at all times. Operatives are warned not to over reach or stretch when working on ladders.

Duct Moisture

Duct Moisture • The presence of moisture in air conditioning ducts is common since the air leaving the air conditioner evaporator is saturated. In Florida, air conditioning is used most of the year providing little time for ducts to dry out. • High moisture in ducts can cake dirt and provide an environment for mold to grow. This situation leads to serious indoor air contamination problems. Cleaning Air Conditioning Ductwork Through neglect, or sometimes normal use over long periods of time, air handling ducts in homes accumulate dirt and molds and bacteria begin to grow. Often the situation is identified when family members begin to experience allergic symptoms. The house has become "sick." Can the ducts in a "sick-house" be restored to a safe level? The question of how to restore contaminated air supply systems is becoming an urgent one. This

WHEN TO TEST

WHEN TO TEST Duct testing is strongly recommended when a new heating and/or air conditioning unit is being installed. If the existing duct system is leaky and inefficient before the new unit is installed, it will still be leaky and inefficient after the new unit is installed—unless the ducts are tested and sealed by a qualified contractor. It does not make sense to install a new, energy-efficient heating and/or air conditioning unit unless the duct system is also energy efficient. Duct testing is also recommended when a diagnostic tune-up is performed on a heating and air conditioning unit. A diagnostic tune-up can improve the operating efficiency of the heating or air conditioning unit itself, but the overall efficiency will still be less than adequate if the duct system is not in good condition. A duct test is necessary to determine leaks, needed repairs, and/or renovations. Duct testing can be performed at any time, however, whether or not new energy efficiency equipment is being installed. It is not unusual to find that sealing, repair, or renovation must be performed to complement a comprehensive HVAC installation

The construction of the two climate rooms

The construction of the two climate rooms, in which ducted units are tested according to Eurovent requirements, or EN/ISO standards, and which are close to the reverberation rooms, have been designed using a similar acoustic isolation approach to that of the reverberation rooms. The climate rooms have been designed taking into account the specific requirements and equipment installation characteristics of air conditioners and heat pumps available in the market. Acoustic tests for several types of equipment require that the rooms have windows that allow correct installation and operation of the equipments under testing. This is the case, for instance, for window-type units, and for in-duct measurements. These are hermetically sealed acoustic windows in order to maintain the required acoustic isolation for the measurement of less noisy machines, and they have a sound attenuation superior to 45 dBA.
The test facilities allow for carrying out acoustic testing of air-to-air, air-towater, water-to- air and water-to-water products with a cooling capacity of up to 50 kW, with the exception of roof top units and liquid chiller packages with remote condenser. To test these types of units, the laboratory is equipped with two air loops of 14,000 m3/h, and two water loops of 12 m3/h, with controlled flows and temperatures conditions

Ground-coupled

Ground-coupled heat pump systems for commercial/institutional buildings have now successfully been introduced in China, even in cold climate regions. Measured seasonal average COPs range from 3.1 in cold regions to 3.3 in milder regions. Few projects have been realised yet, but plans exist for new installations in metropolitan areas and for the Olympics in 2008 in Beijing. Problems encountered in China include lengthy borehole drilling and installation processes, lack of suitable water-source heat pump products and limited availability of appropriate equipment and qualified installation personnel.
As for Europe, ground-coupled heat pumps are mainly applied as heatingonly systems. Heat source systems include bedrock, ground, sea and lake water, groundwater, combinations of these sources and ventilation air. Figure 24 shows countries with significant sales of ground-coupled heat pumps (the first number represents million of inhabitants, the second number the heat pump sales per