Cooling Towers and Evaporative Condensers
ASHRAE Technical Committee 8.6

Scope of TC 8.6

TC 8.6 is concerned with cooling towers, evaporative liquid coolers and condensers, spray ponds, and other types of contact type liquid to air exchangers and applications to complete refrigeration systems, including water treatment.

Custom Content can be placed here.

Handbook

The ASHRAE Handbook is published in a series of four volumes, one of which is revised each year, ensuring that no volume is older than four years.

The Handbook can be purchased at the ASHRAE Bookstore by clicking on this link.

This TC is responsible for the following chapters in the HVAC Systems & Equipment Volume

Condensers
The condenser in a refrigeration system is a heat exchanger that rejects all the heat from the system. This heat consists of heat absorbed by the evaporator plus the heat from the energy input to the compressor. The compressor discharges hot, high-pressure refrigerant gas into the condenser, which rejects heat from the gas to some cooler medium. Thus, the cool refrigerant condenses back to the liquid state and drains from the condenser to continue in the refrigeration cycle. Condensers may be classified by their cooling medium as (l) water-cooled, (2) air-cooled, (3) evaporative (air- and water-cooled), and (4) refrigerant-cooled (cascade systems). The first three types are discussed in this chapter; see Chapter 48 in the 2010 ASHRAE Handbook—Refrigeration for a discussion of cascade-cooled condensers.

Cooling Towers
Most air-conditioning systems and industrial processes generate heat that must be removed and dissipated. Water is commonly used as a heat transfer medium to remove heat from refrigerant condensers or industrial process heat exchangers. In the past, this was accomplished by drawing a continuous stream of water from a utility water supply or a natural body of water, heating it as it passed through the process, and then discharging the water directly to a sewer or returning it to the body of water. Water purchased from utilities for this purpose has become prohibitively ex-pensive because of increased water supply and disposal costs. Similarly, cooling water drawn from natural sources is relatively unavailable because the ecological disturbance caused by the in-creased temperature of discharge water has become unacceptable. Air-cooled heat exchangers cool water by rejecting heat directly to the atmosphere, but the first cost and fan energy consumption of these devices are high and the plan area required is relatively large. They can economically cool water to within approximately 20°F (11 K) of the ambient dry-bulb temperature: too high for the cooling water requirements of most refrigeration systems and many industrial processes. Cooling towers overcome most of these problems and therefore are commonly used to dissipate heat from refrigeration, air-conditioning, and industrial process systems. The water consumption rate of a cooling tower system is only about 5% of that of a once-through system, making it the least expensive system to operate with purchased water supplies. Additionally, the amount of heated water discharged (blowdown) is very small, so the eco-logical effect is greatly reduced. Lastly, cooling towers can cool water to within 4 to 5°F (2 to 3 K) of the ambient wet-bulb temperature, which is always lower than the ambient dry-bulb, or approximately 35°F (19 K) lower than can air-cooled systems of reasonable size(in the 250 to 500 ton [880 to 1760 kW] range). This lower temperature improves the efficiency of the overall system, thereby reducing energy use significantly and increasing process output.

Comment on the Handbook: ASHRAE welcomes your comments on the Handbook or a specific Handbook chapter.  To submit a comment about any aspect or part of the Handbook series, you can use the Handbook Comment Form.

Review a Handbook Chapter: To provide your feedback about a specific Handbook chapter, you can answer the brief survey questions on the Handbook Chapter Review Form.

Programs

Technical committees develop and sponsor technical sessions at the winter and annual conferences. Information about their future technical program is discussed at each TC meeting and at the TC’s Program Subcommittee meeting.

ASHRAE publishes papers and transactions from presentations at its conference events. In addition, ASHRAE records most of the seminar sessions from its conferences on DVD. These DVDs are ideal for use at chapter meetings, in university courses, or company lunch and learns. Products available from the most recent conference may be found here.

A recent program sponsored by this TC:

Winter Meeting 2011 in Las Vegas
TC 8.6 and TC 3.6, along with SSPC191 co-sponsored Seminar 33
"Want Peak System Efficiency from your Water Cooled System? Quit Cooling Dirt!".

Research

Technical Committees are responsible for identifying research topics, proposing research projects, selecting bidders, and monitoring research projects funded by ASHRAE. Information about their specific research program is discussed at each TC meeting and at the TC’s Research Subcommittee meeting.

Standards

ASHRAE writes standards for the purpose of establishing consensus for: 1) methods of test for use in commerce and 2) performance criteria for use as facilitators with which to guide the industry. ASHRAE publishes the following three types of voluntary consensus standards: Method of Measurement or Test (MOT), Standard Design and Standard Practice. ASHRAE does not write rating standards unless a suitable rating standard will not otherwise be available. ASHRAE is accredited by the American National Standards Institute (ANSI) and follows ANSI's requirements for due process and standards development. Standards may be purchased at the ASHRAE Bookstore.

This TC is cognizant for the following standard:

ANSI/ASHRAE Standard 64: Methods of Laboratory Testing Remote Mechanical-Draft Evaporative Refrigerant Condensers

TC 8.6 is also cognizant for standards published by the Cooling Technology Institute

CTI STD-201 (09), Standard for Certification of Water-Cooling Tower Thermal Performance
CTI Code ATC-105 (00), Acceptance Test Code for Water-Cooling Towers

Supplement to CTI Code ATC-105 (96), Acceptance Test Code for Closed Circuit Cooling Towers 

Working Group Link

TIP: If MTG involvement add here otherwise leave blank.

The following link can be used to access the TC8.6 working group:

http://groups.google.com/group/ashrae-tc-86

FAQs

ASHRAE Technical FAQs are provided as a service to ASHRAE members, users of ASHRAE publications, and the general public. While every effort has been made to ensure their accuracy and reliability, they are advisory and provided for informational purposes only, and in many cases represent only one person’s view. They are not intended and should not be relied on as an official statement of ASHRAE. Technical questions not addressed may be submitted to the ASHRAE Technical Services department at tse@ashrae.net.

TC 3.6 is cognizant for an FAQ which overlaps TC 8.6 interests:
How does ASHRAE recommend that cooling towers be cleaned to avoid Legionellosis?