Search Results for: chillers

Engineers’ Dialogue: Higher Efficiency Chilled Water Systems Without VFDs

Learn more about Engineers’ Dialogue: Higher Efficiency Chilled Water Systems Without VFDs at ashrae.org

Installing Absorption Chillers

Journal

Discusses the differences between an absorption chiller design and an electric chiller, and their implications for the architect's role, the structural engineer's role, power loss concerns, the mechanical designer's role and commissioning. Notes additional considerations and provides advice aimed at ensuring that absorption chiller projects run as smoothly as electric chiller projects.

Chillers + Lighting + TES

Journal

As we approach the ten-year anniversary of the chlorofl uorocarbon (CFC) ban that took effect in 1996, only 57% of the estimated 85,486 large tonnage CFC chillers in the U.S. and Canada have been replaced or converted. According to the estimates from the Air-Conditioning and Refrigeration Institute (ARI)1 and the Heating, Refrigeration and Air-Conditioning Institute of Canada (HRAI),2 by the end of 2004, approximately 37,000 CFC chillers still operated in North America.

Optimizing Chillers & Towers

Journal

How a system operates at design conditions is not always a good indicator of its overall annual performance. This article emphasizes controls logic and design conditions and how they can be used to optimize chiller, cooling tower and condenser pump system performance throughout the year. A software model of hour-by-hour energy use for a typical office building in three cities demonstrates the effect of different cooling seasons and wet-bulb profiles. (Results are presented in energy use [kWh]. Actual dollar savings can be estimated by assuming a blended energy rate.)

All-Variable Speed Centrifugal Chiller Plants

Journal

Very often selection programs find variable speed centrifugal chillers to be less cost effective than constant speed chillers. This has made uncertain the future of variable speed in centrifugal chiller plants. However, plants with variable speed chillers can operate much more efficiently than constant speed plants, but only if operating strategies are incorporated that are tailored specifically to these chillers' unique performance characteristics.

Johnson Controls Officially Opens "the World’s Biggest Makerspace for Chillers”

Learn more about Johnson Controls Officially Opens "the World’s Biggest Makerspace for Chillers” at ashrae.org

Addressing noise problems in screw chillers

Journal

Reports that two 300 ton (1055 kW), water-cooled rotary screw chillers and a 125 ton (440 kW) air-cooled rotary screw chillers caused noise problems at two different hospitals. Presents case histories of these two chillers, which demonstrate a noise problem known as 'pure tone' noise, which is often overlooked in the design process by the practising HVAC engineer. Discusses pure tones and describes how to identify pure tone noise sources. Concludes with recommendations on how to deal with noise-critical installations.

Chilled Water System For University Campus

Journal

Until 2005, each of the 30+ buildings on Missouri State University's campus in Springfield was air conditioned via individual water chillers or packaged air-conditioning systems. Many of the buildings on this 160 acre (65 ha) campus are heated using steam from a central boiler plant, distributed via a network of subterranean pipe tunnels, but the air-conditioning systems were a building-by-building mix of direct expansion packages, centrifugal chillers, steam-driven absorption chillers, and air-cooled chillers. The university recently opted to construct a campus district chilled water system and connect many (but not all) of its buildings, making use of new and existing equipment.

STBE Best Paper 2019

Learn more about STBE Best Paper 2019 at ashrae.org

Brief History of Centrifugal Chillers

Journal

My father retired recently from the HVAC business after more than 45 years. He spent one career at Carrier, and a second at Siemens. At his retirement party, there were a group of industry friends, some with experience stretching back to the very early days of the industry. One of these old friends had been a mechanic for the last 60 years, mostly working on centrifugal chillers. They both had a great time reminiscing about the old days.