AIR CONDITIONING
Mini-split Systems the Answer to Church’s out-of-Date Heating and Cooling System
At St. Paul's United Church of Christ in Dallastown, Pa., 16 1960s-era through-the-wall hydronic-electric air-conditioning units were noisy and allowed drafts to enter the sanctuary. What's more, the hydronic coils—over several brutal winters—had endured many freeze/split/repair episodes. ...
2012 AHR Expo Product Preview
HVAC Market Poised for Positive Change
HPAC Engineering spoke with a design engineer, a facility engineer, and a manufacturer and found a market poised for positive change in 2012 and beyond, one that will do so with technology ranging from building information modeling and 24-hour energy analysis replacing outdated technologies. ...
Energy-Services Platform Helps Improve Comfort, Lower Costs for Courthouse
Jackson County worked with Kristi Hubbard, CEM, of McElroy’s Inc.’s Building and Energy Solutions Team on a detailed energy-conservation plan that would allow it to operate the building’s mechanical systems at peak performance while lowering operating costs and increasing comfort...
Valve Selection Crucial in System Design
Manufacturers and designers of air-conditioning, refrigeration, and heat-pump systems must determine the process that will be used for evacuation, charging, and run testing their systems. Valves and process tubes provide the necessary access to the system, but before implementing a solution users must consider the factors specific to each application, including ease-of-use, flow rate, leak rate, cost, and field-service requirements. ...
Design Criteria for Primary/Secondary and Primary-Loop-Only Systems
Editor’s note: The following is a continuation and conclusion of the article “Primary/Secondary-Loop vs. Primary-Loop-Only Systems,”1 published in the December 2010 issue of HPAC Engineering....
A Psychrometric Approach to Air-Side-Economizer Limits
Part 2 of a two-part article examining the effect of economizer operation on the comfort of spaces served by constant-volume air-conditioning systems...
A Psychrometric Approach to Air-Side-Economizer Limits
Constant-volume air-conditioning systems control space air temperature directly and humidity indirectly by modulating or cycling the cooling apparatus. This article examines the effect of economizer operation on the comfort of spaces served by constant-volume air-conditioning systems....
Chilled-Beam Basics
An alternative to conventional variable-air-volume (VAV) systems, chilled beams circulate chilled water through tubing embedded in a metal ceiling fixture to wick away heat. The business end of a chilled beam is made of copper tubing bonded to aluminum fins. The beam is housed in a sheet-metal enclosure typically placed at ceiling level...
Preventing Legionnaires’ Disease in Cooling Towers
As a potential source of Legionella, cooling towers require special attention, but state-of-the-art protection is possible and affordable...
Keeping It Simple with Data Center Cooling
Spot coolers aren’t just temporary fixes for data centers anymore. They also can serve as simple, inexpensive, permanent cooling solutions....
Finer Points of Building Information Modeling
Most of the articles on building information modeling (BIM) published in recent years focus on the generation of buildings and the design of the systems within. The creation of the components that make up those systems is all but ignored. As a result, finding, judging, and improving the quality of existing BIM content quickly is becoming a valuable skill. This article is intended to help you gain that skill....
Cutting a Facility's Cooling Costs
Hybrid chillers and demand-response programs can help reduce operating costs, increase equipment payback...
Evaporative-Cooling-Enhanced Runaround-Coil Heat Recovery
Energy recovery with runaround coils can be greatly enhanced with evaporative cooling of exhaust air, a long-established fact that seems largely forgotten by design engineers and building owners, as all of the applications the author has come across in recent years use dry coils only. ...
Office-Tower Hydronic Update
Melvin Cohen and Associates Inc. was chosen by the State of Illinois Capital Development Board to prepare design documents for bid and construction, and Primera Engineers in Chicago was chosen to provide commissioning for hydronic update on the Michael A. Bilandic Building....
Primary/Secondary-Loop vs. Primary-Loop-Only Systems
Subdividing various systems into a primary/secondary (P/S) loop via a hydraulically dependant interconnection long has been a standard solution for central chilled-water plants in the United States and Europe. This achieves, at a relatively low cost, reasonably good hydraulic separation of central-water-plant cooling-generation systems (primary loop) from distribution piping and terminal units (secondary loop). Primary-loop flow is relatively constant, while secondary-loop flow varies based on load demand. Primary- and secondary-loop water flows are interchangeable....
Ceiling-Mounted Air Conditioner Chosen to Cool Health Clinic's Data Room
At Allina Medical Clinic in Forest Lake, Minn., temperatures in the 10-ft-by-12-ft data room, which houses network switches and other computer and telecommunications equipment the clinic depends on for day-to-day operation, were high, but acceptable. That changed with the installation of additional switchgear and computer equipment and a larger uninterruptible power supply. ...
What 'Hybrid' Means for Cooling
What can the HVAC industry learn from hybrid-vehicle design? Can a hybrid cooling system provide similar performance with less horsepower? Can it provide lower operating costs or extra power when it’s needed—when loads or energy costs are high? How does a hybrid cooling system compare with conventional systems in terms of life-cycle costs?...
Data-Center Uptime & Energy Efficiency
Many data centers are "mission-critical," meaning essential to the core function of an organization. As such, they must remain operational at all times. However, that does not mean significant improvements in energy efficiency and sustainability cannot be made....
Digital Analyzer Ensures Military Techs Are 'on the Same Sheet of Music'
Not long ago, Warren Brader brought his 25 years of experience in HVAC service and maintenance to a major military contractor. His responsibility: maintaining the HVAC equipment at military bases around the world....
Cooling-Tower Design for Critical Applications
Several factors need to be addressed prior to determining the appropriate cooling-tower system for a facility with critical demands. Locations, such as data centers, medical centers, airports, and electronic-chip manufacturers, require special considerations in addition to the requirements of an average cooling-tower system....
Central-Chiller-Plant Modeling
This article will present an alternative central-chiller-plant model, one that is consistent with the laws of thermodynamics and can be executed with a laptop computer. The model will be demonstrated based on an assumed chiller plant operating at design weather conditions in Salt Lake City. ...
Portable Cooling: Equipment and Applications
It's summer, a time when overworked HVAC systems become prone to failure and portable air conditioners are pressed into emergency service. But portable air conditioners are not just for use in hot weather. They can provide solutions to a range of heat-related and comfort challenges year-round. This article will review what facility owners and managers need to know about portable cooling equipment for the summer season and beyond....
Taking a 'Belt and Suspenders' Approach to Cooling
In the world of facility management, no one can afford to be caught unprepared in the event of an emergency. Yet the uncertainty of today’s economy is forcing many facility managers to tempt fate. Organizations of all sizes are under increasing pressure to cut capital expenses and focus on revenue-generating core competencies. As a result, substantial facility investments are being put on hold, with limited or aging equipment forced to operate for as long as possible in what commonly is referred to as “run-to-fail” mode. For facility managers in such predicaments, there is the cooling contingency plan, an affordable, flexible, and reliable way to prepare for the unexpected. ...
Large-Campus District Cooling
Looking to meet its growing cooling needs using less power, UT recently embarked on a district-cooling-optimization project that has seen gas-use quantities return to 1970s levels....
Recent Comments