Document zQmpYBg0OR5OQ9DR1zGakJb3m

American Society of Heating and Ventilating Engineers Guide, 1936 A.S.H.V.E. VENTILATION STANDARDS" It is the intent of the Committee in presenting this report to confine itself to a statement of those requirements which, based on present day knowledge, will provide adequate ventilation for spaces intended for human occupancy. The following standards shall apply to all spaces occupied by human beings in all buildings for which ventilation regulations are to be established. SECTION I--AIR TEMPERATURE AND HUMIDITY The temperature and humidity of the air in such occupied spaces, and in which the only source of contamination is the occupant, shall be maintained at all times during occu pancy at an Effective Temperature, as hereinafter stated. The relative humidity shall be not less than 30 per cent, nor more than 60 per cent in any case. The Effective Temperature shall range between 64 deg and 69 deg when heating or humidification is required, and between 69 deg and 73 deg when cooling or dehumidification is required. These Effective Temperatures shall be maintained at a level of 36 in. above the floor. (See Appendix, Tables A and B). SECTION II--AIR QUALITY The air in such occupied spaces shall at all. times be free from toxic, unhealthful or disagreeable gases and fumes and shall be relatively free from odors and dust. In every space coming within the provisions of these requirements and in which the quality of the air is below the standards prescribed by good medical and engineering practices, due to toxic _ substances, bacteria, dust, excessive temperature, excessive humidity, objectionable odors, or other similar causes, means for ventilating shall be provided so that the quality of the air shall be raised to these standards. SECTION III--AIR MOTION The air in such occupied spaces shall at all times be in constant motion sufficient to maintain a reasonable uniformity of temperature and humidity, but not such as to cause objectionable drafts in any occupied portion of such spaces. The air motion in such occupied spaces, and in which the only source of contamination is the occupant, shall have a velocity of not more than 50 ft per minute, measured at a height of 36 in. above the floor. SECTION IV--AIR DISTRIBUTION The air in all rooms and enclosed spaces shall, under the provisions of these require ments, be distributed with reasonable uniformity, and the variation in the carbon dioxide content of the air shall be taken as a measure of such distribution. The air in a space ventilated in accordance with these requirements, and in which the only source of contamination is the occupant, shall be distributed and circulated so that the variation in the concentration of carbon dioxide, when measured at a height of 36 in. above the floor, shall not exceed one part in 10,(100. SECTION V--AIR QUANTITY The quantity of air used to ventilate the given space during occupancy shall always be sufficient to maintain the standards,of air temperature, air quality, air motion and air distribution as herein required. Not less than 10 cu ft per minute per occupant of\the total air circulated to meet these requirements shall be taken from an outdoor source. APPENDIX Definitions For the purposes of these standards the terms used shall be defined as follows:-- . Ventilation: The process of supplying or removing air by natural or mechanical means, to or from any space. Such air may or may not have been conditioned. (See Air Conditioning). Air Conditioning: The simultaneous control of all or at least the first three of those factors affecting both the physical and chemical conditions of the atmosphere within any structure. These factors' include temperature, humidity, motion, distribution, dust, bacteria, odors, toxic gases, and ionization, most of which affect in greater or lesser degree human health or comfort. "Report of A.S.H.V.B. Committee on Ventilation Standards consisting of W. H. Driscoll, Chairman, J. J. Aeberly, F. Paul Anderson, L. A. Harding. D. D. Kimball. J. R- MeColi, C. L. Riley, W. A. Rowe, Perry West and A. C. Willard, presented at the Semi-Annual Meeting of the Society, Milwaukee, Wis., June, 1932, and adopted by the Society in August, 1932. 74 Chapter 3--Ventilation and Air Conditioning Standards _ __The temperature of the air which is indicated by any type of thermometer Dry-Suib 3* iai?vaporintent or relative humidity of the air. which is not aneciea fi_ . state, the particles of which are large and heavy enough to fall Dust: Solid material m ^ __ -ty jn stm a;r. For instance, particles of fine sand or grit, such as are with increasing velocity, a avcrage diameter of which is approximately 0.01 centimeter, may be called dust, blown on a windy Effective Tcmperatur . arbitrary index of the degree of warmth or cold felt by the human body jdl and movement of the air. Effective temperature is a comp<MUte in response to temperat di 0f temperature, humidity, and air motion into a single value. The index which combines taerea te5iperature has been fixed by the temperature of saturated air which numerical value or Qf ,,armth. induces an (either saturated or superheated steam) occupying any space, which may Huml i ^nlain otier vapors and gases at the same time, or may no . rati although usually expressed in per cent, used to indicate the degree of Relative Humidity- 3Dace resulting from the water vapor present in that space. The presence saturaUon exisUpg in any gtn s^ce^ ^ the same time has nothing to do with the relative humidity of of air or othK_?,d'lends merely on the temperature and partial pressure of the vapor. thei'paC_e'w. tvhlrh the Only Source of Contamination la the Occupant: Spaces in which the SpafS^oni^nination results entirely from the respiratory processes of the occupant, including heat, atmospheric comam body. No manufacturing or industrial processes or other sources of atmospheric contamination! including h^t and moisture. thanBpeople are considered under this title. _ . p,,KCtive Temperatures Ranging prom 64 Deg to 69 Dec por Various Dry-Bulb Tem- Table A. c-ffect______ Dm, attvw HiiMromRS for Still Air for PERSONS -- Temperatures (Deg Fahr) (For use when heating or humidification Is required) Relative Humidities (Per Cent) .. 30 35 40 45 50 55 Effective Temperatures (Degrees) 60 67 68 69 70 73 64.1 65.5 66.2 67.0 64.4 65.1 65.8 66.5 67.3 64.0 64.8 65.4 66.2 66.9 67.7 64.2 65.1 65.8 66.6 67.3 68.1 64.5 65.4 66.2 67.0 67.7 68.5 64.0 64.8 65.7 66.5 67.3 68.1 68.9 64.3 65.1 66.0 66.8 67.7 68.5 74 67.7 68.0 68.4 68.8 75 68.4 68.7 76 69.0 See Fig- 5. Table B Effective Temperatures Ranging from 69 Dec to 73 Deg for Various Dry-Bulb Tem peratures and Relative Humidities for Still Air for Persons Normally Clothed and Slightly AcrrvEa-b (For use when cooling or dehumldlfication ls required) Temperatures (Deg Fahr) Relative Humidities (Per Cent) 40 45 50 55 Effective Temperatures (Degrees) 60 73 69.3 74 69.3 69.7 70.1 75 69.1 69.5 70.0 71.5 71.0. 76 69.0 69.4 69.9 70.5 70.8 71.3 " 71 '& 77 69.7 70.2 70.7 71.2 71.6 72.1 , 72.6 78 70.4 70.9 71.4 71.9 72.4 73.0 79 71.1 71.8 72.2 72.6 80 71.8 72.4 72.9 81 72.5 See Fig. 5. bTbls table applies primarily to cases in which the human body has reached equilibrium with the sur rounding air. A higher plane of summer effective temperatures is required in places of public assembly where the period of occupancy is short, than is required for offices and industrial plants where the period of occupancy is of longer duration. When the period of occupancy is two hours or less, the dry-bulb tempera ture shall be 72 F plus one-third of the difference between the outside dry-bulb temperature and 70 F, and the relative humidity shall not exceed 60 per cent. (See also Table 2.) 75