1、 CEA Bulletin Home Theater HVAC CEA/CEDIA-CEB24 June 2012 NOTICE Consumer Electronics Association (CEA)/Custom Electronic Design and Installation Association (CEDIA) Standards, Bulletins and other technical publications are designed to serve the public interest through eliminating misunderstandings
2、between manufacturers and purchasers, facilitating interchangeability and improvement of products, and assisting the purchaser in selecting and obtaining with minimum delay the proper product for his particular need. Existence of such Standards, Bulletins and other technical publications shall not i
3、n any respect preclude any member or nonmember of CEA/CEDIA from manufacturing or selling products not conforming to such Standards, Bulletins or other technical publications, nor shall the existence of such Standards, Bulletins and other technical publications preclude their voluntary use by those
4、other than CEA/CEDIA members, whether the standard is to be used either domestically or internationally. Standards, Bulletins and other technical publications are adopted by CEA/CEDIA in accordance with the American National Standards Institute (ANSI) patent policy. By such action, CEA/CEDIA does no
5、t assume any liability to any patent owner, nor does it assume any obligation whatever to parties adopting the Standard, Bulletin or other technical publication. This document does not purport to address all safety problems associated with its use or all applicable regulatory requirements. It is the
6、 responsibility of the user of this Standard to establish appropriate safety and health practices and to determine the applicability of regulatory limitations before its use. This document is copyrighted by the Consumer Electronics Association (CEA)/Custom Electronic Design and Installation Associat
7、ion (CEDIA) and may not be reproduced, in whole or part, without written permission. Federal copyright law prohibits unauthorized reproduction of this document by any means. Organizations may obtain permission to reproduce a limited number of copies by entering into a license agreement. Requests to
8、reproduce text, data, charts, figures or other material should be made to CEA/CEDIA. (Formulated under the cognizance of the CEA/CEDIA R10 Residential Systems Committee.) Published by CONSUMER ELECTRONICS ASSOCIATION/ CUSTOM ELECTRONIC DESIGN AND INSTALLATION ASSOCIATION 2012 www.CE.org www.CEDIA.or
9、g All rights reserved CEA/CEDIA-CEB24 1 The following members of the CEA/CEDIA R10 WG5 Home Theater HVAC contributed to the development of this document: Tom Cumberland, Audio Authority Corporation Travis Misterek, Best Buy Co. Inc. Jon Richardson, EchoStar Satellite, LLC. Michael Cogbill, ETC, Inc.
10、 Jay McLellan, Home Automation, Inc. (HAI) Andres Colpa, Home Box Office (HBO) Ann Brigida, InfoComm Eric Lee, Integrated Control Experts Inc. Bob Schluter, Middle Atlantic Products Tameez, Sunderji, Rovi Corporation Walt Zerbe, Russound CEA/CEDIA-CEB24 2 Foreword This bulletin was created by the CE
11、A/CEDIA R10 Residential Systems Committee. This bulletin focuses on sound abatement (ingress and egress) for air handling equipment (including allowing for maximum dynamic range within the listening space) proper air exchanges and treating equipment racks and spaces to maintain adequate operating te
12、mperatures and humidity. CEA/CEDIA-CEB24 3 Table of Contents 1. Introduction 5 2. References . 5 2.1 Informative References 5 2.2 Informative References Acquisition 5 3. Compliance Notation 6 4. Symbols Phone: 404-636-8400; Fax: 404-321-5478; Internet: http:/www.ashrae.org CEA/CEDIA-CEB24 6 ASTM Int
13、ernational Standards 100 Barr Harbor Drive, West Conshohocken, Pennsylvania, USA Phone: (610) 832-9500 Fax: (610) 832-9555 Internet http:/www.astm.org/index.shtml CEA, Consumer Electronics Association, 1919 S. Eads St, Arlington, VA, 22202; Phone; 703-907-7600; Fax: 703-907-7675; Internet: http:/www
14、.ce.org CEDIA, Custom Electronic Design Phone: 317-328-4336; Fax: 317-735-4012; Internet: http:/ CRC Industries America Group, 885 Louis Drive, Warminster, PA 18974-2869; Phone: 215-674-4300; Fax: 215-674-2196; Internet: http:/ Electronics Cooling Magazine; 1000 Germantown Pike, Plymouth Meeting, PA
15、 19462 Phone: Tel: 484-688-0300; Fax: +1 484-688-0303; Internet: http:/www.electronics- Handbook of Thermal Engineering, Frank Kreith; Publisher: CRC Press; 1 edition (December 27, 1999) ISBN-10: 084939581X, ISBN-13: 978-0849395819 SMACNA Standards Sheet Metal and Air Conditioning Contractors Nation
16、al Association, 4201 Lafayette Center Drive, Chantilly, VA 20151-1291; Phone: 703-803-2980; Fax: 703-808-3732; Internet: http:/www.smacna.org The UPTIME Institute; 20 West 37th Street, 6th floor, New York, NY 10018; Phone: 505-946-3459; Internet: http:/www.uptimeinstitute.org Thermal Measurements In
17、 Electronic Cooling,Edited by Kaveh Azar; CRC Press, 1st edition; ISBN-10: 0849332796, ISBN-13: 978-0849332791 3. Compliance Notation “Shall” and “must” denote mandatory provisions and are not used in this bulletin. “Should” denotes a provision that is recommended but not mandatory. “May” denotes a
18、feature whose presence does not preclude compliance, and implementation of which is optional. “Optional” denotes items that may or may not be present in a compliant device. 4. Symbols and Abbreviations ASHRAE American Society of Heating, Refrigerating and Air Conditioning BTU/H British thermal unit
19、per hour CFM Cubic feet per minute dB(A) decibal weighting scale HVAC Heating, Ventilating standard weighting curve applied to audio measurements, designed to reflect the response of the human ear. Dehumidifier: Equipment designed to reduce the amount of water vapor in the ambient atmosphere. Dew Po
20、int: is the temperature at which humid air should be cooled, at constant barometric pressure, for water vapor to condense into water Heat Removal: to provide an operating environment that allows a long equipment life and reliable operation. Humidifier: An apparatus for supplying moisture to the air
21、and for maintaining desired humid conditions Passive Cooling: Use of naturally rising warmer air to remove heat. Active Ventilation: Use of a forced-air device to remove heat, usually a fan or blower. 6. Optimal room environment The design of a home theater can involve disciplines beyond the audio a
22、nd visual elements. One of those is the performance of the HVAC (Heating, Ventilating and Air Conditioning) systems in the home theater environment. Properly designed, it will provide environmental comfort for the occupants, keep the equipment operating at a safe temperature and all will run silentl
23、y so that those soft spoken scenes in the movies will not have unwanted background noise. While solutions can range from a simple cabinet exhaust fan to central heating and cooling units provided by the HVAC mechanical contractor, it should be a carefully considered part of the Home Theater design.
24、The purpose of this document is to provide the Home Theater designer with the requisite background knowledge and guidelines to incorporate all aspects of HVAC into the design. In some cases (i.e. cabinet ventilation, projector exhaust fans, etc.) the Home Theater designer provides most all aspects o
25、f the heat management. In other cases (i.e. occupant comfort, equipment rooms, etc.), the Home Theater designer should collaborate with those responsible CEA/CEDIA-CEB24 8 for the residences HVAC systems. In either case, the HT designer should understand specifications and implementation methods. Th
26、e following provides a summary of the key elements of the HVAC Home Theater design. 6.1 Occupant Comfort To properly design an HVAC system to heat and cool the main theater seating area requires a close collaboration between the HVAC system designer and the theater designer. Obviously, the HVAC desi
27、gner should account for the typical elements in sizing the HVAC system for any space. This can include room size, insulation, orientation to sun, local climate, windows, etc. What the HVAC designer is not likely to know (particularly in the pre-construction/bidding phase) is what additional “heat” e
28、lements result from the use of the room as a theater. Thus, it is incumbent on the theater designer to specify factors such as maximum number of occupants (typically the number of seats), heat loads for equipment in the same space as the occupants (i.e. projectors, amps, receivers, etc), and room us
29、age/activity (watching movies, gaming, entertaining). The optimal room environment for a home theater is one where the temperature and humidity are comfortable to all viewers. In general, the HVAC system should be able to provide a constantly maintained room temperature of 20C 23.9C (68F - 75F) and
30、a relative humidity of 30% - 60%. There should be enough air exchanges per hour to ensure that the amount of heat produced by occupants and the electronic heat load are properly ventilated and do not significantly raise the room temperature or humidity. A good rule of thumb is to design the system b
31、ased on the conditions above in relation to the maximum room occupancy plus one, which allows for system overhead. 6.2 Relative Humidity Relative humidity (RH) is the ratio of moisture present in the air to the amount of moisture the air can hold at saturation, expressed as a percentage. Thus, when
32、air is fully saturated it is at a relative humidity of 100%. Since air expands when heated and contracts when cooled (while the “grains” of moisture generally stay the same), RH is fully dependent on temperature. Thus, as temperature increases then humidity decreases. Similiarly, as temperature decr
33、eases then humidity increases at least until we reach saturation or the dew point. Temperature differences due to climate, geographical region and season can influence what is an acceptable equipment humidity operating range. For example, in a northern climate in winter at 0F, 25% humidity is perfec
34、tly acceptable. However, in summer, 40% at 90F is the higher end for acceptable RH. While these extremes apply for equipment operating in an outdoor environment, home theater equipment would be in a climate controlled CEA/CEDIA-CEB24 9 environment. Under these conditions (68-75F), the operating rela
35、tive humidity should be between 30%-60%. Humidity in a room or area can play an important role in equipment preservation and operation. Ultimately, there are two critical areas to address: dryness and dew point. Let the air get too dry and there is the possibility of creating electrostatic build up
36、that when discharged could cause harm to sensitive electronics. If a room dips below the dew point, then condensation may collect on the equipment. This can occur when cold air is quickly forced into a room with high humidity (i.e. areas with water features, indoor pools/spa, bathrooms). Equipment o
37、perating in this high moisture environment could have problems ranging from erratic operation to complete failure. Managing the relative humidity of a room and/or equipment room can be a delicate balancing act. The room should neither be too dry or too moist. For rooms with dryness problems, a humid
38、ifier may be used to add moisture to the air. Typically, a properly operating area air conditioning (e.g. refrigeration) system will reduce the humidity to within acceptable levels. If needed, a separate dehumidifier unit may be used to augment the AC system and remove excessive moisture. Either dev
39、ice should be connected to a humidistat that monitors and controls the RH within the environment. Human comfort experiments have shown that there is no lower or upper threshold where humidity starts to outweigh other thermal factors. In the comfort zone (when one is not sweating for thermoregulation
40、), humidity has a minimal effect on overall body heat balance and comfort. 6.2.1 Temperature The temperature of all equipment should be operated in a condition that is as close to the manufacturers ambient temperature specifications. The recommended maximum equipment operating environment is 29.4C (
41、85F). The maximum ambient temperature measured at the air inlet should be 75F. It is important to note that for every 10F over 85F digital equipment reliability decreases by 50%. 6.3 Background Noise Background noise from HVAC systems should be managed. One should work closely with the HVAC engineer
42、 and/or contractor to make sure the design of the HVAC system considers all the factors of the theater design. For critical listening environments, the HVAC contractor should design and install a system with an RC (N) of 500 watts or 1700BTU/H CEA/CEDIA-CEB24 13 Figure 1: Air Flow Diagram Figure 2:
43、Air Flow Diagram Passive cooling has the advantages of intrinsic reliability and lower operating costs, and also is the quietest and cleanest. Forcing air to move with active cooling creates more dust buildup than passive cooling. The dust buildup with active cooling can be minimized with the use of
44、 thermostatic fan control, and proportional speed fan control will perform even better. Figure 3: Cooling the mid-size enclosure CEA/CEDIA-CEB24 14 7.5 Overview of the Steps Required to Calculate Airflow Volume for Effective Heat Management Estimate waste heat output for the amplifier(s) Measure (or
45、 estimate) power consumption (current draw in amperes or watts) for all equipment other than amplifiers Enter waste heat and power consumption numbers into appropriate room-temperature formula to obtain exhaust CFM required Select air moving device(s) and their placement Be certain there is adequate
46、 make-up air 75F or less (feeding the rack, closet or equipment room) for the required exhaust CFM and static pressure. Ensure heated air exhaust is not re-circulated to equipment intake or exhaust fan intake. 7.6 Details of steps required for calculating airflow volume for effective heat management
47、: Estimate waste heat output for the amplifier(s). Due to the limited scope of this document, only the most common (AB) class of amplifier is detailed for estimation. A class AB amplifiers idle current draw will be different depending on what type of pre-driver is used. Actual measurement of idle cu
48、rrent is best. Most amplifiers do not create “steady-state” heat, their heat output increases as they are driven harder and with lower frequency content. There are many inexpensive plug-in devices to measure actual idle current draw in equipment, a typical one is shown. Figure 4 shows a very inexpensive watt meter which provides power factor readings in addition to wattage and amperage draw. Simply plug it into an outlet and then plug the equipment into this device. Figure 4: Watt Meter If measurement is not possible, obtain the written
