Climate Of Lahore And Thermal Ease and comfort Environmental Sciences Essay

Climate Of Lahore And Thermal Comfort Environmental Sciences Essay

Chapter 2

2.1 Introduction

Climate has great influence on building because of its electricity consumption and setting up performance. Energy conserving design requires the thought of the climate. The overall heating and cooling requirements in the properties is manipulated by climate during summer months and winter weather. As we’ve selected our internet site in Kala Shah Kaku, Punjab and kala shah kaku is normally situated chemical equations definition in Lahore region therefore the description of the climatic info of Lahore place is given below.

2.2 Climatic classification:

Climate can be classified in conditions building design where the country will be divided into five zones in such a way that the difference of climate from zone to zone can be seen in the building style, gauranting some distinctive provision for each and every zone. Based on these conditions, there are five main climatic zones,






Types of climate Standard Characteristics

Cold Excessive heat loss for the majority of the year

Minimum Temperature: below -15 °C

Temperate Excessive high temperature lost for portion of year

Inadequate heat damage for part of year

Temperature changes: -30 °C to 30 °C

Hot/Dry Overheating for some section of the year

Dry air allow evaporation

Temperature ranges: -10 °C to 45 °C

High radiation

Strong Winds

Hot/Humid Overheating for most of year

Humid air inhibits cooling

Temperature often above 20 C

Mean relative humidity around 80 %

High rainfall in certain months

Table 2.1 typical characteristics of different types of climates

2.3 Climatic zones of Pakistan:

Pakistan has a wide variety of climatic circumstances. The Northern and North- Western elements of Pakistan will be cooler, the centre of the Punjab is incredibly hot and semi-arid, and the Baluchistan is amazing and arid whereas the coastal strip is usually nice and humid. In cool regions, during the winter temperature drops well below the zero. In the desert regions, the maximum temperature remains above 40°C during the majority of the summertime period; with a peak often approaching 50°C.The climatic regions have been divided based on various criteria.

Fig 2.1 map of climatic zones of Pakistan

2.4 Environment of Lahore Region:

Lahore lies 217 meters above ocean level and it lies between 31°15′ and 31°45′ North latitude and 74°1′ and 74°39′ East longitude. On the North and West Lahore is usually bounded by Sheikhupura district, Wagah surrounds Lahore on east, and on the south of Lahore there is normally Kasur District. The river Ravi flows on the North of Lahore. Lahore town has a total land spot of 404km2.

The Lahore location comes beneath the normal composite zone, according to climatic zone map. It lies nearby the hot dry zone and in summertime the wind direction is such that the wind blows northeast towards southwest of the town affecting the climate of Lahore region. The effect of hot dry area starts from March and is still till September as the wind way is southwest this means from hot dry zone towards Lahore region. The main features of this season happen to be that the winds blown will be hot and packed with dust during the daytime but are cooler in night. Throughout the day very strong wind blows. The climate of Lahore region can be divided into the next broad categories:

2.4.1 Popular and dry:

Hot and dry weather condition is found in the weeks of March and April. In these a few months the air is dried up with the apparent sky and no sea breeze to check the excessive high temperature as the Lahore place is located a lot more than 1000 km from the nearest sea, the heat rise is sharp. In the mid-March the utmost heat range reaches up to 90 F and till the center of April temps reaches up to 100 F. Because of clear sky, nights will be cooler having the average temperature of practically 65 F (18 °C). The rainfall is quite less in this period.

2.4.2 Very hot and dry:

In the weeks of Might and June the weather of Lahore is very hot and dry out and the heat is at its peak in these weeks. In the second week of May, the heat range reaches up to 110 F (43 °C).The heat is oppressive, humidity level is definitely low with very hot and dry wind to create loo in local dialect blowing most of the time. The month of June still is still hotter with the temp sometimes reaching to 119 F (48 °C). Yet, in June due to powerful low pressure created by the severe heat, sometimes some moisture from Arabian Sea finds its way to the region and causes rain which for the brings the temp down temporarily.

2.4.3 Warm and wet:

The months of July to September are rainy. Monson clouds travel from the Bay of Bengal and after traveling about 100 km over India reaches Pakistan and enter Lahore from the South- East. This rain system in these a few months called Monsoons. That is a regular characteristic of the Punjab, in this nation. The elements is cool and enjoyable when it rains, usually popular and humid. Although the heat range decreases significantly, from practically 106 F ( 41 °C ) just before the monsoons begins in Lahore to about 95 F ( 35 °C ) but as the monsoon arrives presently there is the upsurge in the relative humidity which improves from significantly less than 25% to a lot more than 65%. The temperature along with the excessive humidity makes the elements very exhausting. Moreover quite often the rain falls with such an avalanche that it drowns the low lying area and persons have to undergo great hardships so this weather is a combined blessing.

2.4.4 Warm and dry:

Warm and dry climate remains in the months of October and November. Because the monsoon stops by the end of September, the weather again becomes dry once again but the temperature is considerably much less hot this time. The dry continental oxygen remains in the region. The temperature is modest to warm during days whereas the weather is normally cooler in nights. The common high temperature is nearly 85 F (29 °C) and during the night due to dry air temperatures it can decrease to 53 F (12 °C) especially towards the end of October or early November. There is absolutely no rain in this year and this season may be the driest season as compared to other seasons. This severe dryness creates a whole lot of dirt and haziness which effects in pollution in the environment.

2.4.5 Cool and dry:

The most pleasurable months of all will be December January February in Lahore. Here is the most perfect weather of Lahore. The peak temperature is nearly 68 F (20 °C) and the peak low temperature is almost 41 F (6 °C). The climate remains neat, refreshing and sunny. On the other hand sometimes, a rainfall bearing system known as western disturbance which includes its source in MEDITERRANEAN AND BEYOND affects the Lahore area and causes rain. However the rain is

not so heavy neither it continues to be for an extended duration. Therefore the weather most of the days remains sunny, dry and refreshing.

In fact, the weather of Lahore is hot and dry for the utmost period of the year with a brief winter period with very refreshing weather.

2.5 Climatic indicators of Lahore:

The table below displays average monthly weather indicators in Lahore which is based on 8 years of historical weather readings.

Temperature in: Fahrenheit

Table 2.2 average every month climate indicators in Lahore

2.6 Hot dried up climate:

The hot dry out equatorial land lying between your two mean annual isotherms of 68°F (20°C) has areas where in fact the temperature during the summer season may reach 43.3°C or may surpass and the vapor pressure is definitely below 25millibars.

2.6.1 Elements of hot dry climate:

1 Seasonal variation

2 Air temperature

3 Humidity

4 Precipitation

5 Wind

6 Sky conditions and solar radiation

7 Dust storm Seasonal variation:

In these regions now there are two major months;

hot season


Fig 3.2 Once a month averages of the minimum amount and maximum daily temperature ranges.

°C/°F Air temperature:

The main features of the climate are heat range remains high during the day 80-130°F (26.67-54.44°C) in the summer months along with solid sunshine reflecting pitilessly from light dried out and parched earth.

There is however a big difference between summer season and winter temperatures because of the varying altitude of sun. During winter the day temperature is normally as high as 90°F (32.22°C) but the temperature is pretty low at nights ,whereas during summer the heat goes down to 50°F(10°C) compared with 70F (21.11C) during the night. Humidity:

Humidity is always low, Relative humidity varies with the air temperature. It can proceed below 20% in evening to over 40% at night. V.P fairly steady changing with area and season from about 500-1500 N/m2 Precipitation:

The quantity of rainfall or precipitation is generally noted as the common mm/working day or mm/month which gives an advantageous indication regarding seasonal alterations.

Usually, average maximum rainfall in 24 hours or the common number of days where a certain volume (in cm.) of rainfall happened is also given. This data is beneficial as an indicator of the rainfall intensity, that will affect the design of windows, roofs and sewerage etc.

July and August will be the months in which most rainfall take place, whereas June and September likewise have some rainy times. For all of those other year, hardly any rain fall occurs in Lahore. Predicated on temperatures and precipitation data, during the hot and rainy season it isn’t advised to move between June and September. The rest of the year is dried up with temperate daytime temperature ranges.

Fig 3.3 Precipitation is certainly any kind of normal water that falls from the sky as part of the weather. Sky circumstances and solar radiations:

The skies will be without clouds for the the majority of the period of the entire year where as frequent dirt haze and storms appear largely in the afternoon. Immediate solar radiation is severe and is amplified by radiation reflected from the barren and light colored landscape.

Fig 3.4 Monthly normal amounts of hours of sunshine per day. Wind:

Winds are mostly native; they are generally lower in the morning however increasing towards afternoon and so are maximal in the afternoon, mostly accompanied by whirlwinds of dirt and sand. Dust particles storms:

Dust storms generally occurs on summer afternoons which may be the most intolerable the main day time , when routine winds blow at 15-220 kilometers per hour. These dust storms also occurs in other parts of the day i.e. in the evening and nights.

2.7 Climatic style of building:

Climate has a great effect on building performance and energy consumption of the setting up. The procedure of recognizing, deducing and managing climatic effects at the building is perhaps the most difficult part of creating design. The main objectives of climatic style of creating should include:

To minimize electricity expense of a building.

To take benefit of maximum of natural energy rather than mechanical system and electricity.

To provide comfy and healthier environment for inhabitants.

2.8 Elements affecting climatic design:

The native micro-weather and site factors influence some of the environmental circumstances of the building. Some important factors related to site should be included while producing the climatic analysis:

Topography- elevation, slopes, hills and valleys, ground area conditions how do you find the area of a rhombus.

Vegetations – height, mass, silhouette, texture, position, growth patterns.

Built forms – local buildings, surface conditions

Important thermal design elements which should be considered include: solar heating gain, conduction heat stream and ventilation heat stream. The design variables in architectural terms which are essential to be looked at are:

Shape – surface-to-volume ratio; orientation; building elevation.

Building fabric – materials and construction; thermal insulation; surface attributes; shading and sunlight control.

Fenestration – the size, placement and orientation of home windows; window glass materials; external and internal shading devices

Ventilation – air-tightness; outdoor fresh air; cross ventilation and normal ventilation.

2.9 Thermal comfort:

There is no accepted common for thermal comfort. This is simply not astonishing, as people can and do live in a variety of climates from the equator to huge latitudes. An Internationally- approved definition of thermal convenience, used by ASHRAE, is “that condition of mind which expresses satisfaction with the thermal environment” (ISO7330).

Perceptions of this environment are influenced by weather temperature, radiant temperature, relative humidity, weather velocity, activity and garments.

Fig 3.5 attaining comfort in buildings

2.9.1 The comfort zone:

The Comfort Zone means the number of temperature circumstances of air motion, humidity and contact with immediate radiations, under which a normally clothed person feels comfortable. This will differ for Indoor conditions as compared with Outdoor conditions. This may also vary for numerous cultures and areas and varying climate circumstances.

As an Architects we apply our buildings never to only create relaxed inside environments, but also aesthetical and beneficial spaces outside our structures.

2.9.2 Thermal relaxation index:

A thermal convenience index serves the target to evaluate the effect of environmental element on the thermal sense of inhabitants. Quantity of methods have been found in the previously to judge the thermal comfort level. However it is not possible to gratify every person in a construction and a tiny number of folks are always discontented with the thermal environment because of individual variations. Several initiatives have been made to create a subjective and quantitative method of representing the thermal ease.

Thermal comfort state in tropical summer conditions is given by Sharma and All at the Central Setting up Analysis Institute, Roorkee, India. The ranges and optimum values receive in table.

Thermal sensation

Range °C

Optimum value °C

Slightly cool






Slightly warm



Table 3.3: temperatures ranges in different thermal zones

2.9.3 Optimal settings for indoor temperature:

Researchers have carried out much research on the best option comfort conditions, and have come up with general comfort effects like powerful warmth, the recent ease standards established by ASHRAE (American society of heating, refrigerating and air state engineers) for an individual performing light do the job are:

Thermal comfort conditions:

Air temperature 73-77 F Relative humidity below 60 %

Mean radiant temp add up to air temperature

Air velocity 10-45 ft/min