Hawaii Building Engineers Association

IAQ During Construction

Indoor Air Quality during Construction and System Startup

When contractors come in to work in our buildings they can release significant amounts of dust and other indoor air pollutants. Contractors need to make sure that not only occupied areas are protected but our systems are protected too. Contractors should be held liable for indoor air quality and damages to air delivery systems.

Dry wall dust, when air borne can enter our air handlers through the return air system ductwork and foul our ducts and damage the coils of the air handlers. Drywall dust is like cement and can imbed its self into the coil restricting flow and causing blower problems. Cleaning drywall dust from a coil is almost impossible and will harden like cement. Sufficient air flow will result and the efficiency of the unit will decrease significantly. The 62.1 User manual of the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) does justice to IAQ considerations during construction and how it is affected by startup procedures. It is important that contractors be aware of this information for the sake of legal protection, keeping up with the latest information is a professional responsibility. According to the document, construction phase requirements apply when a new building is constructed, an addition is attached to an existing building; and when alterations are made to existing buildings. However the document states” not all the requirements are applicable to each of the three circumstances”.

The requirement clearly states that air handlers should not be stated without filters, and the filters should be replaced after construction. So who knows if the construction crew is starting the equipment when your not there!  An inspection of equipment before you start the project with the construction project manager and an after construction inspection will ensure the protection of the buildings assets during construction. Please send any information on this topic to the editor.

Future of CFC Chillers

The future of CFC chillers

Despite CFCs being banned in new equipment since 1995, many CFC chillers are still in use. The Montreal Protocol mandated that all chillers operating on outlawed CFC refrigerant be replaced or reengineered for refrigerant change outs by 2010. How ever the size and cost of a chiller puts replacement out of reach and will be every ones last thing to do. The time, money, planning, and possible building modifications required to replace a chiller is over whelming in some cases. When it comes to chiller replacement, the cost can be $200 per ton for equipment and another $100 per ton to install it. Often with a lengthy payback and not to mention the prospect of a helicopter lift or crane lift from a 30 story building.

            Building owners with aggressive preventive maintenance programs find that their chillers are working fine and can in some cases extend the life cycle for a chiller. Eventually the equipment must be overhauled and a decision must be made to repair or replace. Chillers today are lasting longer, leaking less, and keeping the building occupants comfortable. Run it into the ground or replace it is the question that owners face. Especially if a trouble free chiller would cost $120,000 to replace it, the economic argument run it till it quits. Chiller maintenance costs are low in comparison to purchased equipment costs and in many cases provide a better return on investment.

           Motivating factors to change out a chiller would be based on forward thinking to replace before a major breakdown or to provide a better level of service. Are the service frequencies going up? Are the efficiencies going down for the equipment and it costs more to operate? Are their still technicians available to work on the older equipment?

            Capacity reduction will occur with older chillers when the refrigerant is changed out. An old R-11 machine will be replaced with R-123 and capacity will be reduced because of the refrigerant characteristics. Before you know it a $50,000 conversion will be half the cost of a new chiller. New refrigerants will eat up the motor linings, and gaskets of the machine. If you wait to long the disposal of expired refrigerant will carry a hefty price tag. Today you may receive a credit tomorrow you may have to pay. R-410A and screw chillers are the rave and the other choices are still R-134A and R-22 chillers.

I would sat that about 40% of chillers will replaced by 2010 and all the rest will be changed out as a last resort and come with a hefty price tag. Please respond to me if you have any comments on this topic. 

Surge Protection

Know the Benefits of Surge Protection

As energy demands increase for the Hawaiian Islands so does the likely hood of energy surges to our equipment. Power quality will diminish as use goes up and it could get worse before it gets better.

Why surge protection? Each year our buildings experience 300 potentially damaging electrical surges per year. Heating, Ventilation, Air Conditioning (HVAC) and elevator equipment are very sensitive to these surges. These units are a costly investment for the owners and typically there is no protection. A surge is a high amplitude short duration electrical fluctuation that can cause harm to electrical, electromechanical, and electronic equipment. Surges are caused by lighting, utility events, and internal events. Lighting is the most obvious and most sensational type of surge. Lighting rarely happens in Hawaii, what we see are utility events that consist of crossover of phases, capacitor switching, grid shifting, inductive loads, and open neutrals. Internal events in buildings are the more likely source of a surge. A general Electric (GE) and National Power Labs (NPL) studies have shown that 65 to 80 percent of transient surges are caused by internally from pumps (well or pool), A/C condenser motors, refrigeration motors and other motors around the building. These events can lead to 1) degradation 2) destruction 3) downtime.

Surge protectors provide protection against :

• Incoming surges
• Bounce surges from inrush current

A surge protector works by shunting the voltage to ground. A good ground is imperative the National Electrical Code (NEC) states maximum resistance at ground is to be 25 ohms.

Additional reading available from HBEA and HECO.         

Please forward any responses to this email to the editor.

Server Room Cooling Technology

Heat from server rooms is a killer. It gets in your return system and adds load to your air handler latent and sensible heat loads. How well you handle your hot exhaust air from your equipment is quite a concern and usually depends on the design of the equipment.

Today’s sensitive data equipment may have thousands of hot air flow paths, which represent the total waste heat output that must be cooled or removed. Total wattage of a server room could be as high as 3 tons of air conditioning load. Multiplied by 10 tenants and know you load is 30 tons x amount floors could equal a small chiller alone. So do you cool the room or the equipment? The traditional way was to exhaust the air and cool the room.  The problem with this approach was room based cooling provide inadequate airflow across the equipment.

Newer cooling systems designs shorten the distance between heat sources and heat removal systems to ensure a more predictable cooling method. In rack orientated architectures, the air conditioning units are directly mounted or housed within the IT racks. The resulting air flow paths are short and defined and immune to room constraints for installing. Manufactures such as APC, and their InfraStruXure InRowRC and SC cooling units coupled with RackAirContainment and Hot Aisle Containment Systems eliminate hot spots and neutralize hot air by preventing recirculation into sensitive IT equipment. Check it out at www.InfraStruXure.com