When is duct cleaning appropriate?

When is duct cleaning appropriate? Although the value of regular duct cleaning remains questionable, the U.S. Environmental Protection Agency (EPA) and indoor air specialists agree that duct cleaning (or, in some cases, duct replacement) is appropriate in the following circumstances: • Permanent or persistent water damage in ducts   • Slime or microbial growth observed in ducts   • Debris build‐up in ducts that restricts airflow • Dust discharging from supply diffusers   • Offensive odors originating in ductwork or HVAC component. BEFORE hiring a duct cleaning contractor, make sure you can answer “YES” to all of these questions: 9 Are there known or observed contaminants in the ductwork? 9 Have you confirmed the type and quantity of contaminants based on testing or observation? 9 Are the contaminants (or their by‐ products) capable of entering occupied spaces? 9 Have you identified and controlled the source of the contaminant?   9 Will the duct cleaning effectively remove, inactivate, or neutralize the contaminant? 9 Have you considered other options, such as removal of affected ductwork? 9 Is duct cleaning the only (or most effective) solution? In all cases, duct cleaning should be undertaken only after the source of the contaminant has been identified and controlled. Otherwise, the problem will not go away. For instance, the water source

Operatives to board

Operatives to board over any open kitchen equipment e.g. hobs or ranges. Ensure equipment has cooled down sufficiently and cover all solid surfaces with appropriate sheeting.
5  Operatives to set up access equipment e.g. trestle, step ladders, etc.
6  Operatives to ascend access equipment and carry out sealing procedure of all holes and apertures.
7  Operatives to descend to floor level and prepare cleaning solution as per the manufacturer’s instructions. Note: refer to COSHH assessment supplied.
8  Operatives to check work equipment to be used as per cleaning specification. Where steam cleaners are to be used check that all connections are properly tightened, electric cabling is sound and equipment has current PAT test label or certificate.
9  Operatives to transfer cleaning equipment on to the access equipment taking care to ensure that no spillages occur and that safe manual handling techniques are observed.

Operatives will clean

Operatives will clean all necessary surfaces ensuring that where necessary care is taken not to cause damage to any fragile surfaces. Operatives to use cloths or  ‘Greenies’ as required.
7  On completion of cleaning operatives will descend the ladder using both hands, operatives must not slide down ladders at any time.
8  Operatives will check floor area for any sign of drips or spillage and clean up any that are found.
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.

Air compressors were introduced

 Air compressors were introduced as a more effective alternative to portable blowers. The use of skippers or snakes, which moved through systems with compressed air to assist in air washing air ducts. • Compressed air-washing and vacuuming are now sometimes augmented by manual scrubbing with brushes and flexible rods and whips and can assist in cleaning hard to reach dirt buildups in air handling systems. Where ducts are lined with fiberglass insulation, this treatment could damage the insulation and release fiberglass fibers to further contaminate air. • The use of HEPA filtration can be used to trap very small particles. This might be important for commercial duct cleaning where equipment exhaust stays inside a building, but offers little for residential duct cleaning where filtration equipment is placed outside. • For truly contaminated duct systems professionals can cut into the duct work to insert the vacuum line to remove localized dirt build-up. Some commercial air duct cleaners are equipped with tiny fiber-optic cameras to assist in locating dirt build-up and to confirm cleaning effectiveness.

YOUR DUCT SYSTEM

YOUR DUCT SYSTEM In most residential and small commercial central heating and cooling systems, the conditioned (heated or cooled) air is delivered to each room through supply ducts and returned through the return duct to the furnace or air conditioner. The condition of both sections of this ductwork is vital to the overall efficiency of your heating and cooling system. What can go wrong? In some buildings, air escapes through poorly connected, disconnected, or deteriorated ducts, which can result in little conditioned air actually reaching your living or work space, leaving the area too warm or too cold. If the return duct system is leaky, it could be drawing in outside, stale, or polluted air and distributing it throughout the building; this air could come

Opening

Opening
Professor Wu Yuanwei of the China Academy of Building Research (CABR) and Mr John Ryan of the United States Department of Energy (DOE), chairman of the National and International Organising Committee respectively, opened the conference. Secretary General Mr Shi Dinghuan of the China Ministry of Science and Technology and Mr Chen Yiuing of the China Ministry of Construction welcomed the more than 330 participants.
The IEA representative at the conference, Mr Hanns-Joachim Neef, underlined the IEA members’ primary goals: energy security, economic growth and environmental protection for a sustainable (energy consuming) society. He recalled China’s challenging goal of ongoing zero growth in energy consumption by 2040, with energy
efficiency being one of the main building blocks in China’s energy policy. High-efficiency heat pumps can play an important role in achieving this goal.
ASHRAE president Mr Bill Coad used a lesson in thermodynamic history to underline his statement that ‘There is no turning back’ and that ‘Change is a fact of life that has resulted in a higher quality of life for mankind’. The greatest challenge to the human race will be to maintain and advance its quality of life in the face of dwindling energy reserves and an environment that is continually being degraded. It is the engineering community that faces the challenge of designing equipment and systems that use less energy to accomplish the same goals. There is also considerable scope for reduction of consumption. The opportunities for a sustainable future are there, and heat pumps can play a

Even though ground-source

Even though ground-source technology is reliable and cost-effective, continued research is needed to further lower the variable cost and broaden the applicability of ground-source heat pump systems. Research areas include: • computationally efficient simulation methods for ground loop heat exchangers, especially horizontal designs with above ground interaction; • more cost-effective vertical heat exchangers; •lower cost methods for estimating soil thermal properties; • design methodologies that incorporate system simulation, allowing interactions between the building system and the heat rejecter/exchanger system; • optimised fluid pumping system configurations and controls for reduced variable costs.
Several organisations have been active in transferring the technology to the market, which has significantly improved awareness by architects and engineers. However, more is needed to make ground-source heat pump systems a widely accepted technology.