Comfort conditions

The temperature and humidity should be maintained at comfort conditions consistent with the operator s expected level of activity in order to minimise perspiration. Constant temperature and humidity may also be required in machine rooms to prevent the etching or corrosion of machine parts. If perspiration causes only minor damage to the product and results in few rejects, then inside design conditions at 27°C and 40% rh are satisfactory. Where even small amounts of perspiration cause extreme damage to precision-machined parts and result in a high amount of rejects, inside design conditions of 21°C and 40% rh are recommended. 

In the current review, the term effectiveness of air distribution will be used to describe the ratio of the occupied zone area (where thermal comfort and contaminant concentration are within ranges required by standards and codes) to the total occupied zone area. This hygienic criterion allows one to judge how well the HVAC system fulfills its main task—creating thermal comfort conditions and controlling contaminants in the occupied zone. 

These factors compensate for the relationship between the inside air and mean surface temperature and provide similar comfort conditions at... 

Comfort conditions The environmental conditions in a space that will ensure statistically the majority of occupants are comfortable. Relates to thermal, acoustic, and visual conditions. 

An air conditioning system uses an assembly of equipment to treat air. Normally the assembly includes a heating system for modifying winter indoor temperature and humidity a refrigeration system for modifying summer temperature and humidity, a means to maintain indoor air quality (i.e., air filters and fresh air intake) a method of distribution of conditioned air and a control system, such as a thermostat, to maintain desired comfort conditions. 

Spot cooling A ventilation strategy whereby the space temperature is allowed to rise and air movement is induced locally to provide comfort conditions within a limited area. 

For comfort in normal office or residential occupation, with percentage saturations between 35 and 70%, control of the dry bulb will result in comfortable conditions for most persons. Feelings of personal comfort are as variable as human nature and at any one time 10% of the occupants of a space may feel too hot and 10% too cold, while the 80% majority are comfortable. Such variations frequently arise from lack or excess of local air movement, or proximity to cold windows, rather than an extreme of temperature or moisture content. 

Alternatively, supply air is used directly, without re-heat. It now picks up the quantity of heat A (about three times as much) and only one-third the amount of air is needed. The final condition will he about 55% saturation. This is still well within comfort conditions, and should be acceptable (line ad). 

Before mechanical refrigeration systems were introduced, people cooled their food with ice and snow, found or made on-site or gathered in the mountains. This practice survives today in the Taurus Mountains of Turkey. Ice was stored in icehouses usually partially buried in the ground and lined with straw or sawdust. Remains of these structures survive on many farms in Europe and North America. Ice has long been used for space comfort conditioning. In the early nineteenth century, ice was placed in air ducts to cool and dehumidify warm air blown by fans. 

All these characteristics allow to measure FAD with a statistic quality and a reliability out of reach of flash sources. Moreover, in the case of polymers, it is generally not possible to purify samples as much as one would wish to perform a fluorescence experiment in comfortable conditions, and the free choice of wavelength permitted by the continuous spectrum of the synchrotron source is essential. In this regard, lasers, which also provide very intense and short light pulses usable for fluorescence experiments somewhat less flexible. This may partly explain... 

It should be noted that no Ihcnnal environment will please everyone. No matter what we do, some people will expres.s some discomfort. Tire thermal comfort zone is based on a 90 percent acceptance rate. Thai is, an environment is deemed comfortable if only 10 percent of the people are dissatisfied with it. Metabolism decreases somewhat with age, but it has no effect on the comfort zone. Research indicates that there is no appreciable difference between ihe environments preferred by old and young people. Experiments also show that uieu and women prefer almost the same envirorunent. The metabolism rate of women is somewhat lower, but lliis is compensated by their slightly lower skin lemperature and evaporative loss. Also, there is no significant varialion in the comfort zoue from one part of the world to another and from winter to summer. Therefore, the same thermal coinfort conditions can be used llirouglwut the world in any season. Also, people cannot acclimatize themselves to prefer different comfort conditions. 

Consideration should be given to temperature and relative humidity control once a significant volume of filtered air is delivered across operators, comfort conditioning is usually found necessary. 

There are some common areas of significant corrosion impact for major home appliances and comfort conditioning appliances. The corrosion types are internal corrosion from process water and external corrosion from wet conditions. 

Fanger P O, Ostberg O, Nicholl A, et al. Heat comfort conditions during day and night. European Journal of Applied Physiology and Occupational Physiology, 1974, (4) 120. 

The idea of thermal comfort is based on subjective evaluations of thermal environments. Individuals rate conditions as cold, cool, neutral, warm, or hot. An early thermal comfort scale was the Effective Temperature Scale. More recent studies led to a standard for defining thermal comfort conditions by ASHRAE. Standard 55-2013 is the most recent edition, but updates occur every few years. 

Occupational hygiene deals not only with overt threats to health but also in a positive sense with the achievement of optimal comfort conditions for workers, i.e. the reduction of discomfort factors which may cause irritation, loss of concentration, impaired work efficiency and general decreased quality of life. 

By using air as a vehicle for conveying heat or cooling to a workplace to maintain reasonably comfortable conditions by employing air conditioning or a warm air ventilation system. 

Most of those not active in PI will have encountered applications of process intensification in their domestic environment, rather than in their work. The microwave oven uses electric fields to intensify the energy input to foodstuffs and liquids, to cook and/or raise their temperature. We may find it difficult to find other orders of magnitude intensification processes within our living space , but an examination of consumer electronics and the power devices needed to drive such systems can reveal existing and potential applications of PI. Even the heat pump/chiller, used to maintain comfort conditions, has benefited from the rotating intensification methods invented by Professor Ramshaw. 

In addition, the absolute displacements are cause of problems, as high amplitude could produce uncomfortable noise. The effects of the absolute accelerations must be also considered, as they are especially noticeable on equipment and machines. The human comfort conditions are affected too as high accelerations produce an inertial force on the people preventing them from acting comfortably. 

A facility s demand has two components base load and variable load.The base load, which is fairly constant, represents the electric service required to maintain a facility s environment and comfort conditions (e.g., lighting and HVAC).The variable load, which is superimposed on the base load, depends on the business activity of the facihty, weather, and other variables. 

People doing moderate levels of work in non-air-conditioned industrial plants might require as much as a 250-ft/min (1.3-m/s) velocity of air movement in order to be able to continue working as the air temperature approaches 90°F (32°C). This would not necessarily provide a full-comfort condition, but it would provide acceptable relief Loose paper, hair, and other light... 

Some 80 percent of the electricity used by industry is apphed for electric drives which are elements of electromechanical systems. These systems are used to form (extrude, roll, cast, press, and spin), shape (mill, ream, drill, hone, and tap), and transport (conveyors, elevators, brakes, fans, pumps, and compressors). The remaining 20 percent of industry s electrical use is applied for electrolytic processes, process heating, lighting, and comfort conditioning. 

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