Air-cooling evaporators used in ammonia systems have traditionally been made using galvanized (zinc-coated) carbon steel. There are other metals that are compatible with ammonia, including stainless steel and aluminum. Aluminum, in fact, can provide several benefits.
Air duct leakage should be a concern to both the designer and the
building owner because of its potential impact on initial construction costs,
energy usage, and system performance. No matter the size, the total benefit of the
duct system is based and measured on the peak fan efficiency for that system.
The six basic steps of brazing are highlighted: good fit and proper clearance; cleaning the metals; fluxing the parts; assemble for brazing; brazing the assembly; and cleaning the brazed joint.
Boiler “short cycling” occurs when an oversized boiler quickly satisfies process or space heating demands, and then shuts down until heat is again required. This article points out the inefficiency of short cycling and provides suggested actions to maximize boiler efficiency.
Remember that automatic control systems are automatic in operation, but not self-repairing. Unless a building has a service contract with a reputable controls contractor to inspect and calibrate the HVAC control system every six months, it is very likely that the HVAC system is not providing maximum comfort.
In a workspace world driven by demands for anytime, anywhere information, wireless technologies are becoming dominant. A flexible wireless infrastructure that supports IT networks, security applications, HVAC, and more is emerging as a surefire way to increase the value of commercial office space.
While hackers and viruses often garner the most attention in the realm of computer threats, many contractors overlook the ways that physical damage can adversely impact their business. Computer hardware failure, power surges, and/or damage from flood or fire could destroy years of work orders, accounting records, and more.
Sometimes it is advantageous to use more than one fan in a system. The fans may be located in close proximity to each other, or separated by quite a distance such as a supply and exhaust fan. Most often there is some compelling reason to use more than one fan in a single system.
This article focuses on stand-alone data loggers
in conjunction with the logging capabilities of the BAS in the context of use
by a commissioning provider. It also provides tips on specific
procedures and techniques that will enable the efficient and effective use of
data loggers to analyze building performance.
Boilers equipped with condensing economizers can have an overall efficiency that exceeds 90 percent. A condensing economizer can increase overall heat recovery and steam system efficiency by up to 10 percent by reducing the flue gas temperature below its dew point, resulting in improved waste heat recovery.
The key to a successful waste heat recovery project is optimizing the use of the recovered energy. By installing a condensing economizer, companies can improve overall heat recovery and steam system efficiency by up to 10 percent.
At first, the call sounded like one we hear all the time — not enough heat in a room that had been added onto a house. The service guy told me the radiators were big enough, and that the house had an old gravity hot water system. He asked if I’d stop by to look at it.
Facility managers of the future will be astonished when they
discover that building systems were not always integrated into a
single enterprise-wide information technology network.
Yes, the “old days” of operating a building will be compared to writing letters
instead of text messaging. This future scenario is a lot closer than it seems.
Some applications utilize
an input or supply voltage of 277-1-60. While some components are
available for direct application of 277-1-60 power, most manufacturers find that the use of a buck-boost transformer to
lower the voltage is more cost effective.
Ask
many school administrators about the air quality inside their buildings, and
the frank answer is liable to be “Well, we don’t know.”
They should. School
air quality and student performance go together as naturally as breathing in
and breathing out.
The first Copeland Scroll® rolled off the production line in 1987, and the cooling industry was changed in a way that would benefit contractors and their customers in many, many ways. The prime benefits have been efficiency and product reliability.
Many features of the Scroll focus on preventing compressor failures, but the Scroll’s primary design also improves efficiency and reliability thanks to its classic, concentric compression scroll, in which one spiral-shaped part fits into another; the space between the two parts contains crescent-shaped gas pockets.
CLASSIC SCROLL OPERATION
In operation, one Scroll is fixed in place while the other orbits within the first. The refrigerant gas is drawn in by the movement and forced toward the center of the scroll through successively smaller pockets, thereby increasing the gas pressure until it reaches its maximum pressure. Then it’s released through a discharge port in the fixed scroll.
Copeland Scroll compressors are unique in the industry because they feature both axial and radial compliance in their design, whereas other scroll models utilize a mechanically fixed design and scroll tip seals.
Axial compliance refers to the ability of the scrolls to separate in the axial — or vertical — direction remaining in continuous contact around an axis, in all normal operating conditions, ensuring minimal leakage without the use of tip seals. Radial compliance refers to the ability of the scroll flanks to separate. These features of the Scroll design allow the compressor to be more tolerant of liquid refrigerant or debris than other technologies, making for a compressor that is extremely durable and reliable.
The combination of axial and radial compliance means that Scroll compressors actually “wear in” rather than wearing out. Continuous flank contact, maintained by centrifugal force, also minimizes gas leakage and maximizes efficiency of the compressor.
Next month: Tech Tips will begin examining the Scroll’s improved reliability through its oil control system.
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