Plumbing/Piping/Pumping
Stainless-Steel Drainage Piping Chosen for new Jail Kitchen/Warehouse Facility
On Aug. 28, 2005, as Hurricane Katrina hammered the coast of Louisiana, the levee system in New Orleans failed, and 80 percent of the city and large tracts of neighboring parishes were flooded with sewage-rich seawater. One of the challenges presented by the swelling floodwaters concerned the evacuation of thousands of prisoners from the downtown Orleans Parish prison system. All 12 jail facilities were overrun by floodwaters, with most tagged as “totally destroyed” in the hurricane’s wake. Today, construction of permanent, greatly more storm-resistant jail facilities is under way. ...
Applying DOAS With Heat Pipes
Combining heat pipes and dedicated outside air creates reliable, energy-efficient, low-maintenance systems....
Energy Impacts of Chilled-Water-Piping Configuration
This article will discuss the energy consumption of the three basic configurations of chilled-water piping currently in use: constant primary flow (CPF), constant primary flow/variable secondary flow (P/S), and variable primary flow (VPF). Also, it will discuss the attributes of equipment-room space, installed cost, and control complexity....
System Simulation Modeling
The system simulation modeling used in preparation of this article consists of a set of simultaneous equations that obey the laws of physics and thermodynamics and includes the nonlinear performance characteristics of plant equipment, air-side equipment, and buildings, always arriving at energy equilibrium after a change in steady-state condition...
Polypropylene-Random Pipe Eliminates Electrolysis in Tennessee VA Hospital
ASI/Southern Mechanical Inc. introduced to the hospital staff polypropylene-random (PP-R) pipe manufactured by Aquatherm Inc. PP-R pipe, which is electrolysis-resistant, corrosion-proof, chemically inert, and durable, has been used in more than 70 countries for nearly four decades. ...
Anatomy of Load Delta-T
Low-load delta-T is said1 to exist in nearly every large distributed chilled-water system. The first three articles in this series2,3,4 described strategies for coping with low-load delta-T in plants with primary/secondary (P/S) and primary-only (P-only) distribution pumping. This article will discuss why low-load delta-T is so pervasive in central chiller plants and introduce a means of forcing load delta-T to 10°F....
7 Steps to Optimizing a Central Plant
Optimization of a central chiller plant can achieve and sustain ongoing energy and cost savings...
Efficient Control of a Primary-Only Plant
This is the third article in a five-article series on central-chiller-plant modeling. This article will develop a rationale for controlling a P-only plant at a level of performance on par with that of a P/S plant operating at the low-load delta-T conditions defined by the previous two articles....
Primary/Secondary vs. Primary-Only Pumping
In 1996, an article in this magazine1 sparked debate of the merits of primary/secondary (P/S) vs. primary-only (P-only) pumping of distribution water...
Improving Pump Efficiency
As energy costs rise, equipment suppliers, system designers, and operators focus increasingly on maximizing the efficiency of HVAC-system components to...
Product Spotlight
Pump-monitoring device An intelligent monitoring device that provides an early warning of pending pump trouble to help maximize pump performance and minimize...
Investigation Into the Failure of Chilled-Water-Pipe Insulation
The chilled-water system in a South Florida high-rise went into operation in April. By June, the pipe insulation was saturated with water, and condensation was dripping on people’s heads. The problem cost more than $20 million to correct. What went wrong?...
Template-Assisted Crystallization
After years of using salt-based water softening for critical boiler-treatment applications, Hahn Family Wines sought an environmentally friendlier form of water treatment, one free of chemicals, salt, and waste discharge. For its main water supply, it commissioned the installation of a template-assisted-crystallization (TAC) central treatment system....
The Art of Variable-Speed Pumping to a (delta) T
Variable-speed hydronic circulation has been around for years. With the advent of packaged controls on pumps, it is easier than ever to implement. To take a closer look at the concept of variable-speed pumping, I asked professional engineer and manager of application engineering for Taco Inc. Greg Cunniff and Warwick, R.I.-based plumbing and heating specialist William J. Riley to explain the best applications and key benefits of the technology. ...
Expanded School’s Potable-Water Needs Met With Polypropylene-Random Piping
To meet the needs of a growing under-18 population, Logan City School District in Logan, Utah, embarked on an expansion of Woodruff Elementary School during the winter of 2007-2008. With copper prices at an all-time high, Randy Godfrey, owner of plumbing contractor Carson Mechanical, proposed an alternative for potable-water piping: polypropylene-random (PP-R) Aquatherm Greenpipe....
Epoxy Lining Revitalizes Water Piping in University's Largest Dorm Complex
Constructed in 1972, Moody Towers is the largest complex of residence halls on the University of Houston's (UH's) urban campus. Consisting of two 18-story...
Taming Turbulent Piping-System Flow
Turbulent flow churns, spins, tumbles, and creates unexpected havoc in piping systems. If left unchecked, it can shorten the life of critical piping components,...
Specifying Piping Systems
Engineers are under pressure like never before to generate mechanical designs that are energy-efficient and environmentally friendly. Of course, first...
Grooved Mechanical Pipe-Joining Systems
Like all materials, pipe experiences dimensional changes as a result of changes in temperature, expanding when heated and contracting when cooled. The key to accommodating thermal expansion and contraction in a piping system is to allow predictable and controlled piping-system movement....
Vertical Inline Pumps Save on Space, Installation for University of Miami
The Miller School of Medicine at the University of Miami is committed to becoming one of the country's leading bioscience research institutions. It also...
Ground-Source Heat Pumps: Keys to Design, Installation
Amid the current push to “go green” by building high-efficiency, environmentally sound, sustainable HVAC systems, heat pumps — particularly those that use the earth's geothermal energy to serve as a heat sink and source — are generating a lot of buzz. Ground-source heat-pump (GSHP) systems operate like every other HVAC system: They move energy from one place to another. Although that sounds simple, HVAC engineers and designers owe their livelihoods to the complexities. ...
With Help of Water-Source Heat Pumps, Historic Minneapolis Building Reborn
Completed in 1928, Midtown Exchange in south Minneapolis served as a retail and distribution center for Sears, Roebuck and Co. until closing in 1994....
Polypropylene Piping Alternative Fits Nashville Hotel Installation to a Tee
During the fall of 2008, Jimmy Hughes, owner and president of Hughes Bro. Inc., was in the process of bidding a potable-water-piping job at a 65-room, four-story Comfort Suites hotel in Nashville, Tenn. With copper prices at an all-time high, he was looking for a more cost-effective alternative. It was at that time he learned of a solution that had been used successfully in other parts of the world for more than 30 years: Aquatherm Greenpipe. But it was not only Greenpipe's lower cost that caught Hughes' and the hotel owner's attention....
Make It Work!
While working for a contractor overseas about 25 years ago, I often was required to manage construction projects at remote locations. Considering the...
Coalescing Air Separator Removes Entrapped, Entrained, Dissolved Air
Utilizing a conventional air separator that removed entrained air air traveling in a water stream in bubbles that can be seen with the human eye but not...
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