4 FM quick reads on HVAC
1. Water Safety Plan Is Needed to Combat Legionella
Today's tip: Legionnaire's disease is still a threat, and facility managers should have a plan to combat it.
Legionnaire's Disease does not make headlines the way it used to. But that does not mean the pneumonia caused by the bacteria, legionella, is no longer a risk. According to the Centers for Disease Control, between 8,000 and 10,000 people wind up in the hospital every year because of legionella. And those numbers may well underestimate the extent of the problem, says CDC, because many cases are either not diagnosed or not reported. Summer is the biggest problem time, but the illness can strike 12 months of the year. And Legionnaire's Disease is a serious condition, leading to death in 5 to 30 percent of cases, according to CDC.
People contract the disease by inhaling a mist or vapor contaminated with legionella. Sources of the problem include plumbing systems, cooling towers, humidifiers, whirlpools, fountains and mist machines.
The only way to determine if legionella is present is to test the water, says Matthew Frieje, president of HC Info. The bacteria can be present in well-maintained systems, not just systems that are poorly maintained, he says.
Facility managers should take steps to ensure that their facilities' water systems do not become breeding grounds for legionella. The World Health Organization recommends developing a water safety plan to evaluate risks of exposure to legionella. A water safety plan assesses hazards and ranks them in order of priority. It also calls for ongoing operational monitoring of control measures, such as the use of biocides, the prevention of stagnant water and the keeping of water temperature outside of the range in which legionella grows the best, to the extent possible. Legionella grows best in water temperatures between 20 C (68 F) and 50 C (122 F)
When seeking expertise to help prevent Legionnaire's disease, facility managers should look for unbiased advice, rather than relying on manufacturers selling products designed to help control legionella.
2. Focus on Energy Efficiency: Sub-Metering Strategies
This is Chris Matt, Managing Editor - Print & E-Media with Maintenance Solutions magazine. Today's tip is using sub-metering to manage energy use.
The first step in sifting through sub-metering technology is to identify the organization's essential energy-management needs and determine the way the facility can address these needs with a data-collection system.
The type of energy information many facilities require often is beyond the capability of one master utility meter. Sub-metering systems, combined with useable and comprehensive data-collection systems, can give managers much more detailed load profiling. Managers can use the collected data to:
• understand energy-use patterns and trends
• implement demand response and control to avoid costly ratchet and peak utility charges
• profile an entire facility for demand-management and load-shedding measures
• locate true spare capacity within the electrical system.
In its simplest form, sub-metering involves installing separate meters downstream of the primary billing meter. These meters monitor specific points in the system. In campus settings, for example, sub-meters might be set up on a building-by-building basis to allocate energy costs among departments. In single buildings, managers can group specific system circuits and monitor the distribution system to minimize the number of sub-meters.
Some sub-meters can transfer data, while others also can record and store interval data. Other intelligent-breaker technologies allow system operators to control individual circuits in a distribution system separately, as well as monitor the system's data separately.
At a minimum, managers should install sub-meters on lighting, HVAC, alternative-energy systems, and other key pieces of equipment, which will produce the most valuable trending data. Managers can reconfigure and display this data to the building occupants and visitors with a energy dashboard that presents the information in a way they understand.
3. Questions to Ask When Renting HVAC Equipment
Today's tip comes from Jim Piper, contributing editor for Building Operating Management. When a decision has been made to rent HVAC equipment, facility managers should evaluate a range of factors when selecting a rental partner. Here are some questions to ask:
• What pre- and post-rental services are offered by the rental company?
• Are there additional charges for those services?
• Does the company arrange and pay for delivery and pickup of the equipment?
• Is engineering assistance available to help with connecting the rental equipment to the existing building systems?
• What type of maintenance support does the rental company offer, and what is its guaranteed response time?
• Is the equipment maintained by the rental company's staff or is it contracted out to a service company?
• Where is the inventory of rental equipment located? For small items, most companies stock equipment locally. For larger items, such as building chillers and cooling towers, equipment is typically stocked at regional distribution centers. Depending on where those centers are located, the time and cost to deliver equipment may be excessive.
• What is the rental company's policy regarding replacing and updating equipment? In the past, it was not uncommon to find that companies were willing to rent out practically any age equipment as long as it was still operating. As could be expected, the older the equipment, the less reliable it was. Today, most rental companies tend to keep equipment for a period of time well short of its rated service life. That approach reduces operating costs while allowing the companies to provide the most advanced equipment possible. For the facility manager, there is the added benefit of greater reliability.
4. Occupant Input Can Aid HVAC Retrofits
Today's tip comes from James Piper, contributing editor for Building Operating Management.
One of the goals of any HVAC retrofit is to improve the level of service. While FMs might understand the technical problems with existing HVAC systems, they will not fully comprehend the needs of building occupants unless they get them involved in the retrofit process. Occupants are the ones that understand their operations best. FMs will not know what system will best meet their needs - indeed, they might not even have a good understanding of what their HVAC needs are - but occupants will give FMs a clearer understanding of what the HVAC system will be expected to do.
Building occupants are also good sources of information on the performance of existing systems. Frequently, they are aware of problems that go unreported to building staff. That information is often crucial in setting priorities for HVAC system retrofits.
There's one other reason to get occupants involved: HVAC retrofits can be disruptive. They can require temporary relocation of occupants. Heating or cooling service may be disrupted for days or weeks. A schedule of moves and outages will have to be developed. Without the cooperation of occupants, retrofits can turn into scheduling nightmares.
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