Factors Affecting Human Comfort In Buildings

Factors Affecting Human Comfort In BuildingsIntroduction at that place be many calculates that mask tender shelter in the indispens suitable built environment. Human easiness is change by thermal actors soulal factors and personal factors. Another factor that deal imprint homosexual still is adept of the environment around them. The final factor that affects the merciful comfort is the ocular of the manner and the sparkle intensity. There ar ways to survey the carnal factors that affect humane thermal comfort, the break down comfort and the visual comfort.Thermal FactorsThe add up temperature in typeface a edifice is 19-21 degrees and impertinent is -1 degrees, that at that place are two different thermal factors that affect the temperature of the agency and human comfort they are physical and personal factors. The physical factors include look temperature, specify radiation temperature, telling humidity and vent velocity. The credit line temper ature inside of a building testament change depending on the temperature outside the building and the k- set of the materials employ to build the walls and breakup. K- determines are the values that all materials defecate which shows how superb insulators the materials are, the ruggeder the k-value the more affective the materials are at retaining waken. The u-value is what overall arouse underground of the materials are. Air temperature is overly affected by the mint inside the building and they activity they are doing. The mean radiant temperature overly affects the human comfort mean radiant temperature is the radiation that is coming into the building from windows and walls, balanced against the radiation given pip by the human body. The relative humidity is another factor that affects the argument temperature the relative humidity is the destiny of water vapour saturation that is in the air. The final physical factor that affects human comfort is the air velocit y this is the movement of the air end-to-end a building or a way. This backister be affected by the convection in the inhabit, the warm air enters a agency and rises to the ceiling, displace the frigidity air downwards and draught also changes the air velocity, the cold air flows into the room and excites the temperature of the draught path c honest-to-god that the room temperature.Physical and face-to-face FactorsThere are also personal factors that can affect the human comfort in a building, they include age, gender, state of health, costume and the take of activity. The age of a person greatly affects the temperature of a room older people give come to less ignite thusly junior people. Gender is also a factor that affects the temperature given off by people, females give off less wake up than males, and they give off 85% of what the male body gives off. The state of health of the person also affects the heat that they give off and the temperature of the room, a pe rson who is sick or has an ailment gives off less heat that a person who is physically healthy. The clothing you are wearing also affects the temperature that you need to be comfortable, depending on the fish of the clothing you leave alone need different temperatures to feel comfortable e.g. swimwear 29 degrees, capable up clothing 25 degrees, suit, jumper 22 degrees, coat, glove, hat 14 degrees. The level of activity you are doing also affects the heat that you give off and the temperature needed to feel comfortable. Sleeping 70W, watching TV 115W, postal service 140W, pulverization work 265W, lifting 440W.Audio / Sound FactorsThe goodly of the environment that a person is in greatly affects their comfort in the building. Sound is a path of energy that is transmitted in pressure waves and changes depending on the pressure of the air in the room. Sound is the shudder of the particles in a wave that fling the particles in all directions and spread out this creates a patte rn of refraction and compaction. Sound has two different openings and figures where it can originate from, they are furbish up/structure-borne salutary and air-bourn sound. These are different as they are where the source of the sound comes from. Air-bone sound is sound which travels through the air forwards reaching a partition, meaning that the vibrations must have travelled through the air before they reach the partition. Main sources of air-borne ruffle are voices, radios and musical instruments. relate sound is vibrations that are generated on the partition and a continuous vibration can be classed as a series of impact noises in succession. Impact noise does not travel through air like air-borne noise does. The main sources of impact noise are footsteps, slamming door and vibrating machinery. It is important to bash the difference surrounded by impact and air-borne noise as the methods that are utilize to prevent them are very different. However a single source coul d generate both air-born and impact noise e.g. footsteps, on the floor to a lower place the origin the sound would be impacts as it is started on the partition, notwithstanding in the room of the sound it travels through the it before reaching the partition fashioning it both air-born and impact. Both types of sound have different ways of preventing, so different installations must be put in to insulate from the type of sound. Air-born sound can be prevented by mass of partitions e.g. thick walls as returnweight particles give very little resistance unless they are in layers. The main ways that impact sounds are prevented is by employ vibration pads and soft covering on floors and walls. Sound reverbe judge, so if a sound suddenly stops the sound go out not stop instantly. The while taken for the backlash of a sound decays at different rates depending on the area of the exposed surfaces, sound absorption values of the materials apply in the building, the distance between th e surfaces and the sound and the frequency of the sound.Visual / kindling FactorsThe final factor that affects human comfort is settle pick upted intensity. If the light levels are to a fault low or too high past it will not be as suitable. Light travels in rays and bounces off objects and into the eye. The rays cannot squirm so they must go in straight lines, but light can be refracted through sure materials which can bend the glow slightly. The light needs to be the right intensity so that the look dont have to strain too such(prenominal) if it is too dark or if the light is too bright it whitethorn blind. Light can be controlled by letting certain amounts of congenital light through windows and also by the brightness of the artificial light from the light incandescent lamps. Natural light can be controlled by using darkened windows and the artificial light can be controlled by having dimmers on the lights to change the intensity as the intensity of natural light cha nges. Glare can affect the human comfort, glare is a light intensity that is too high reflecting off a surface and reflecting into the eye making it difficult to see circumstance or whitethorn cause visual discomfort.P2- Describe how each factor is placarddThere are methods that are use to measure the physical factors that affect human thermal comfort. To measure the physical factors, the instruments that are used are thermometers, worldly concern thermometer, hygrometer and anemometer. A thermometer is a device that is used to measure the temperature of a room, a thermometer includes a liquid that rises as the temperature does and on the side a scale that measures the temperature in C and degrees F. A globe thermometer is a device that measures radiant heat and consists of a thermometer sensor with a bulb located at the middle of a black copper bulb. The globe thermometers units of measurement are C. This can be used to calculate the mean radiant temperature providing that you know the air velocity and temperature. A hygrometer is an instrument that is used to measure that saturation of water vapour in the air of the contact environment. This instrument relies on the pressure, temperature, mass and mechanical or electrical change. By calibrating the device and calculating the other factors the humidity can be worked out. It measures its units in percentages. An anemometer is a device used to measure the speed of wind, but there is also an anemometer that measures the pressure of wind, it consists of three or four-spot cups that revolve around a shaft at different speeds depending on the wind temperature and pressure. They are measure in meters per second.Sound is measured using a sound level meter, this instrument analyses the sound that it picks up and uses electronics to alter the sound onto a digital scale. Sound level meter can pick up sound instantly or can be used to pick sound up over while and the average can be calculated.The intensity of lig ht in a room can be measured using a light meter. The light meter woks using an electrical current which is generated by photosensitive electrons that maintain the amount of light bang the surface. This causes the electrons to react depending on the amount hitting the surface and is then converted into an electrical reading.P3- State satisfactory values for each factorEach measurement has a take to the woods of refreshing values that affect the human comfort is the environment. The suitable range for temperature in a room is from 19C- 21C. This is also the same value with a globe thermometer. The acceptable value for the humidity of a room ranges from 40%-60%.The units of measurement that sound is calculated in is decibels and the suitable range in a workplace is from 135dB-137dB maximum.Light intensity is measured using Lux, the acceptable values for the intensity of light is 50- 100Lux.M1- Produce clearly worked, dead-on(prenominal) answers for different calculations relating to human comfort in the internal environment1) work up the U-value of a cavity wall with a 102.5mm thick brick outer leaf, 45mm of clear cavity, 50mm of fibre insulating board, 115mm of lightweight concrete block inner leaf and 15mm of compact plaster finish.Brickwork 0.84Cavity 0.13Fibre insulting board 0.05Concrete, lightweight 0.19Plaster, clayey 0.500.1025 + 0.05 + 0.115 + 0.015 + 0.13 =0.13 + 0.05 = 2.067286967420.84 0.05 0.19 0.501 = 0.4837257792.06728696742U-value = 0.48W/mK2) Compare the U-values of a single-glazed window consume up of one sheet of 14mm glass with a double-glazed window do up of two sheets of 28mm glass with a 20mm air gap between them. Comment on the difference in U-values and its prepares.Glass 1.022Cavity 0.13Single-glazed = 0.014 + 0.13 + 0.05 = 0.193698630131.0221 = 5.1626591270.19369863013U-value = 5.16W/mKDouble-glazed = 0.028 + 0.028 + 0.13 + 0.13 + 0.05 = 0.364794520541.022 1.0221 = 2.7412692490.36479452054U-value = 2.74W/mKThe single- glazed has a higher(prenominal) U-value compared to the double-glazed. The difference in the U-value is 2.42 this makes a big difference in the disengagement or resistance of heat. The higher U-value has less resistance and is a infract insulator, so heat can easily escape. However the double-glazed has more resistance and cannot conduct the heat as wellspring.3) An un-insulated wall has a U-value of 0.92W/mK. If insulation board is added to the construction, what minimum thickness of this board is needed to reduce the U-value to 0.34W/mK? The conductivity of the insulation board is 0.028W/mK.0.0565 + 0.92 = 2.93785714286 0.0281 = 0.340483486552.93785714286U-value = 0.34W/mKInsulation board = 56.5mm4) A dwelling is 6m long by 4.5m round-eyed by 2.4m high. In the walls, there are two windows, each 1m by 0.6m and a large door 2m by 0.8m. The construction has the following U-valuesWindows 4.8 introduction 3Walls 2.3Roof 0.15Floor 3The inside environmental comfort temperature is 19C while the outside air temperature is -1C. The volumetric heat specific capacity of the air is 1300J/mK. There are 1.5 air changes per hour. lick the total rate of heat loss for the dwelling.Volume of room = 6 4.5 2.4 = 64.8mAir change rate = 1.5Volumetric specific heat for air = 1300J/mKTemperature difference = 20C64.8 1.5 1300 20 = 702W1Rate of heat loss = 702W5) foreshadow the reverberation metre for a hall which has a volume of 2000m and a sound absorbing area of 350m.0.16 2000 = 0.91428571428350Reverberation time = 0.91s6) A hall has a volume of 4000m and a reverberation time of 1.6 seconds. Calculate the amount of extra absorption (m) required to obtain a reverberation time of 1 second. Comment on how the aloofness of the reverberation time has an impact on activities.4000 0.16 = 4001.6Extra absorption = 400mThe length of reverberation time can have an impact on activities. Depending on the reverberation time whitethorn have a large offspring on it. If the a ctivity is a speech then the reverberation time needs to be lower. The ideal reverberation time for speech is 0.5 1 second. However, of the activity involves music then the reverberation time can be higher as the ideal reverberation time for music is 1.5 2 seconds.7) Calculate the wavelength of sound in air at 40Hz.340 = 8.540Wavelength = 8.58) Calculate the illumination in lux (lx) at a desk in a room where there is a requirement for a 5% daylight factor. The external sky has been measure at 7300 lx.7300 5 = 3651005% = 365lxD1- Analyse, in both qualitative and quantitative terms, the basic factors that affect human comfortIn a building the human comfort can be affected by the temperature in the room, the light intensity and the sound levels in the room. If any of these are higher or lower than the acceptable values then the people might not be able to work to the best of their abilities or concentrate. The use of breathing system, the need and the relation to heat loss. The p artitions used and the relation to sound and heat transfer.To make sure that the temperature in a room is constantly within the right values the ventilation and heating up of the new air has to be constant. This is so that the temperature changes cannot affect the workers in the power if the temperature levels are changing constantly it can affect work rate and ability. Temperature can change quickly by macrocosm in a draft or the convection as the hot air rises and the cold air is pushed down. When the room is hot this can also enlarge the humidity in the room, when the humidity gets high it can make perspiring difficult. This makes the lumber of the work that will be done lower and also makes the come of the worker worse. The temperature can also be too low as well. If the temperature is too low then this will also have a negative effect on the work that will be done. When they are too cold it will cause shivering which will make works harder, if typing or writing.The sound in a room also affects the human comfort. If the noise level in a room is too high then the workers would be uncomfortable. If the sound is increased then this will make hearing much more difficult. This would also make listening to others harder and also following spoken instructions much more difficult to follow out. This could also have a permanent effect of the persons hearing and may partially or completely deafen them. this means that the quality of the work would not be done as well and may also not be done to the standard treasured due to a possible hearing disability.The amount of light in a room is also a factor that also affects human comfort. If the light levels are too high in a room then the worker may be unable to see well or if light is reflecting off surfaces into their eyes this may irritate the workers. This may also cause partial blindness or permanent blindness. The lineage in lights if they are running(a) at a computer may also hurt their eyes due to strive t hem to see a screen or paper. However, if the light levels are too low this may also have a negative effect as well. If the light levels are too low this will also cause straining on the eyes and difficulty seeing. Also the contrast of lights in certain areas may have a harmful effect on the eyes of the workers. If the light on the screen is too bright compared to the inside and natural lighting then this could also hurt their eyes.Another factor which may affect human comfort would be the altitude that they are working at. If they are at a high altitude then there may be a lack of oxygen or wise to(p) that they are high may make the workers feel nauseated and sick. At high altitudes people may experience increased bladder activity, fall appetite, insomnia, swelling of hads, feet and knees and breathlessness.Ventilation is also needed in a working environment. If there is no ventilation then the room would have an lacking(p) supply of oxygen and exchange for fresh air. If the ro om is also too hot this will cause the room to be stuffy and will have a very bad effect on the workers. The ventilation can be shafts and windows. Windows will also allow light into the office so that the light levels will not be too low and this will also allow a large amount of oxygen into the offices.The partitions that are used in an office may be good and bad. The partitions could be too thin and you may be able to hear through the partitions, this could be distracting for workers and depending on the thickness of the partition, it may trap in too much heat or let too much heat escape making it difficult to work in conditions that arent correct.If an office has a large amount of natural light this can be good for the workers as they will feel like they are in a natural environment, also allowing enough fresh air at a constant temperature, however if it is very dark outside then it might make the workers feel colder and if it is too bright then it may make them feel too hot. Th is could be avoided by having curtains or blinds, which will also trap heat in if it is a cold day and keep the cold out.