Assessment Sheet Thermal Comfort Order Instructions: Answer all question. But DO NOT answer question assessment 4.
Read the learner guide then answer the questions of a separate document.
| NAME: | DATE: | ||
| S = SATISFACTORY NYS = NOT YET SATISFACTORY | TRAINER TO COMPLETE | ||
| Module 1.2 Thermal comfort, climate & solar radiation | S | NYS | |
| 7. Define each of the following terms in your own words, and explain how they relate to NatHERS assessment/residential dwellings:
· Thermal comfort · Dry and wet bulb temperature · Thermal neutrality · Cooling climate, heating climate, and mixed climate · Micro-climate · Diurnal temperature swing · Heating and cooling degree hours · Solar radiation · Solar geometry · Summer solstice, winter solstice, and Equinox · True north and magnetic north · Urban heat island effect |
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| 8. What is a wind rose and how can it be used when designing a home? What limitations apply to the use of wind roses when designing the ventilation of a home? Provide an example of a wind rose for the area in which you live and explain how to interpret it. |
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| 9. How does solar radiation impact on building thermal performance? Give specific examples of locations in which solar radiation would have the greatest impact and locations in which it would have less impact. How can solar radiation be used positively in the design of a residential building in your climate zone? |
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| 10. How does the position of the sun in the sky change across the year and how can this affect the thermal comfort within a building? Give specific examples. |
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| 11. Describe how you would locate the direction of true north at a building site. Why is it important to know this when designing an energy efficient building? |
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| WORK-BASED ACTIVITIES | |||
| Assessment Task 2: Use the 8 NCC climate zones to complete the following activities:
A) Identify which climate zone you live in, and describe the key characteristics of the climate in that zone. B) Describe the key differences between the following types of climates, and identify 2 well-known Australian towns in each zone: · Tropical climate and cool temperate climate · Hot dry climate and mild temperate climate · Sub-tropical climate and an alpine climate. C) Identify the NCC climate zone that the following cities and towns are in: · Toowoomba, QLD · Katherine, NT · Mannum, SA · Broome, WA · Orange, NSW · Geraldton, WA · Launceston, TAS · Albury-Wodonga, VIC/NSW D) How are the climate zones used within a NatHERS accredited software application different from the NCC climate zones? Why are different climate zones used for NatHERS assessments? |
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| Assessment Task 3: Calculate the angle of the sun in the sky (solar altitude) at noon for the equinox and both solstices in each of the following locations:
· Toowoomba, QLD · Katherine, NT · Mannum, SA · Broome, WA · Orange, NSW · Geraldton, WA · Launceston, TAS · Albury-Wodonga, VIC/NSW. How would the position of the sun in each location affect the thermal comfort and passive design strategies recommended for use in each location? |
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| Assessment Task 4: Draw a diagram to illustrate the different elements that impact on a person’s thermal comfort within a home at any particular point in time. Label all the elements that are shown in your diagram.
Explain in writing how the following factors contribute to thermal comfort: · Temperature, both air temperature and radiant temperature · Humidity · Clothing · Air movement · A person’s activity level · How acclimatized the person is to the particular environment |
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Assessment Sheet Thermal Comfort Sample Answer
Assessment Sheet Thermal Comfort
7.
- Thermal Comfort:
It is a zone in between cool/cold and warm/hot in which people feel relaxed/comfortable because they neither feel too cold nor too warm. An environment is established in which the human body feel thermally comfortable with the temperature difference. The only reason for its difficulty to achieve is that it involves psychological and physical factors that changes according to the living standards of individual from place to place.
- Dry and wet bulb temperature
It is the temperature inside a dry bulb which measures air temperature when it’s bulb is fully exposed to air, without the interference of direct moisture and radiant heat.
On the other hand, Wet bulb temperature is the measuring of air temperature by exposing the thermometer totally to the air with no protection for moisture and radiant heat.
- Thermal neutrality
It is the creation or occurrence of the environmental zone in which zone is at thermal balance with the equity of coolness and warmth.
- Cooling Climate, heating climate, and mixed climate
The time period in the year when the winter season starts is known as cooling climate. The heating climate is the opposite which is the period when the summer season starts. The mixed climate is the period when the individual doesn’t feel cool nor warm.
- Micro-Climate
An artificially created thermal zone either through the help of air conditioner or any heating system in order to create an environment that’s thermal conditions is different from outside.
- Diurnal temperature swing
DTR or Diurnal temperature swing is the difference between the maximum temperature on earth and minimum temperature on a daily purpose.
- Heating and cooling degree hours
The time in the day during which temperature reaches below 18 Celsius or 65 Fahrenheit and there is a need for the heating system.
- Solar radiation
The radiations that reach to earth from sun.
- Solar geometry
It is the factor for determining Shading, heat gain and the light’s potential energy, its penetration power.
- Summer solstice, winter solstice, and Equinox
It is the certain time each year (21 June and 22 December) on which the duration of daytime is the longest in the case for summer solstice or the start of summer and shortest day for winter solstice or the start of winter.
While equinox is the time of the year (22 September and 20 March) on which sun crosses the equator when daytime is equal to night time.
- True north and magnetic north
True north is the geographic direction of earth North pole. It is the north that we don’t use commonly.
While magnetic north is the one created due to magnetic lines of the north pole. Our compass always points towards that and that’s what we use commonly.
- Urban heat island effect
A significant change in temperature of some city or Metropolitan area due to the Human activities from that of the surrounding areas. Such as Shanghai temperature difference from its surroundings. (Nicol 2012, Reynolds 2000, Oleary 2008/2009)
8.
Wind Rose:
Graphical method of presenting the winds condition, speed and direction with certain time intervals at specified locations.
It is used by comprehending circular format that shows the frequency of blowing wind along with its direction per unit time. Differentiation between the winds frequency is done by the different concentric circle presents in a circular format. There are 16 cardinal directions in Windrose.
The drawbacks or limitations for using this method are that you will have to attain the height of 10 m at least to perform this method. Secondly, at 10 m height of a building, the wind speed is usually very slow. Wind speed is dependent upon the obstacles that surround the house. Therefore, it is not preferred for home design purpose hence preferably the existing knowledge about the summer and winter breeze must be known for designing purpose.
For example, where I live there are the large plantation of trees which blocks air from one direction, if wind rose is used then it will not cover the wind speed and direction for a different period of time for different intensity and let’s suppose when the trees would be gone there would be different scenario created. (Reynolds 2000)
9.
Direct Solar radiations are a great blessing but only in winter mostly. Because in summer time it warms up the building walls, windows and the air that accumulates insides the house hence increasing the temperature of a house. Mostly good designers, what they do is direct the building face such as veranda towards the maximum sunlight which helps to warm the house in winter. While in summer the rooms are prevented from direct access to the heat. Countries near to the equator design their house for minimum direct solar radiations.
At the equator, the building thermal level is high due to maximum solar radiations coming from the sun at perpendicular intercept on earth.
While near to poles, minimum solar radiations are observed resulting in designing homes for maximum solar radiations available.
Solar radiations can be used positively in many sense such as in cold areas for the purpose of warming the house, in hotter areas for the production of electricity by steam at the small level for homes and for sun drying of clothes. (Learner Guide, 2013)
10.
As the earth is moving around sun hence slightly different path of the sun is observed with the days passing by. Earth revolves around the sun at different points of the orbit, facing the sun with different angles. Hence it appears to us that sun position in sky changes.
With the different position of the sun in the sky with the time, day and night time changes reducing or increasing the time of direct solar radiations to the earth surface. When the earth is revolving nearest to the sun surface, it makes days go longer and the thermal changes take place.
For example, the sun is in the sky for a longer time during summer that gives more time for the house to get warmed up above the comfortable zone while during winter with the days shorter, houses aren’t that warm enough. (Reynolds 2000)
11.
Compass doesn’t tell us the direction of true north. Either by looking at the map and placing the compass on your current location and finding the difference between the magnetic north on the compass and imaginary axis of rotation of the earth in the northern hemisphere on the map. Adding or subtracting the difference will lead to the direction of true north.
True north is necessary for the energy efficient building because it would be easy to calculate the time period for solar radiation in a day, hence proving great assistance in designing homes on the bases of good lightening and heating/cooling environment. (Reynolds 2000, Oleary 2008/2009)
Assessment Sheet Thermal Comfort Assessment Task 2:
- For Nigeria the climate zone is 3: It is dry and warm. Mostly desert.
- City names in each zones
- Tropical Climate and cool temperate climate
Comfortable temperature for humans ranging around 26C makes tropical Climate for example in: Sydney, Wollongong
Cool temperature climate is the one that is mostly cool with less warmth during summer examples: Hobart and Canberra
- Hot Dry Climate and mild temperate climate:
Hot dry climate is the extreme heated climate in cities like: Cooktown and Darwin
While mild climate is the one where there is neither too cold nor too hot. Examples are: Melbourne, Adelaide
- Sub-tropical Climate and an alpine climate
Sub-tropical are those which are slightly vary from the human comfort zone. Example: Penrith, Broken Hill
Mountainous area is a tropical climate. Example, Katoomba, Mount Tomah
(Reynolds 2000, Oleary 2008/2009)
C NCC climate zone of Cities:
- Toowomba, QLD is zone 3: Hot Dry summer, warm winter
- Katherine, NT is zone 5: warm temperature
- Mannum, SA is zone 6: mild temperature
- Broome, WA is zone 5: warm temperature
- Orange, NSW is zone 7: Cool Temperature
- Geraldton, WA is zone 2: warm humid summer, mild winter
- Launceton, TAS is zone 7: Cool Temperature
- Albury-Wordonga, VIC/NSW: is zone 5: warm temperature
(Reynolds 2000, Oleary 2008/2009)
D In NatHERS accredited software, different factors are taken into account such as the effect of air and radiant temperature around the designed house, humidity and air speed. These factors are all related to inside and around the house environment only. While the zones refer to the whole area of city or region that have a similar temperature which varies to +- 4C. (Olearly 2008/2009, Reynolds 2000)
Different climate zones used for NatHERS includes:
- Radiant temperature varies in winter and summer
- Humidity level
- Dryness level and alpine
Assessment Task 3. The angle of the sun(degree) in Summer Solstice, winter solstice and in Equinox
| City | Latitude | Summer Solstice | winter solstice | Equinox |
| Toowoomba, QLD | 27.56 | 85.9 degree | 38.94 degree | 62.4 degree |
| Katherine, NT | 14.45 | 99.0 degree | 52.05 degree | 75.5 degree |
| Mannum, SA | 34.91 | 78.6 degree | 31.59 degree | 55.1 degree |
| Broome, WA | 17.96 | 95.5 degree | 48.54 degree | 72.0 degree |
| Orange, NSW | 33.28 | 80.2 degree | 33.22 degree | 56.7 degree |
| Geraldton, WA | 28.78 | 84.7 degree | 37.72 degree | 61.2 degree |
| Launceston, TAS | 41.43 | 72.1 degree) | 25.07 degree | 48.6 degree |
| Orange, NSW | 33.28 | 80.2 degree | 33.22 degree | 56.7 degree |
- Thermal Comfort level (Nicol 2012, Oleary 2008/2009)
| City | Latitude | Summer Solstice | winter solstice | Equinox |
| Toowomba, QLD | 27.56 | (warm temperature) | (Mild Winter) | (Mild temperature) |
| Katherine, NT | 14.45 | (High Humidity summer) | (Warm Winter) | (warm temperature) |
| Mannum, SA | 34.91 | (warm temperature) | (Mild Winter) | (Cool Temperature) |
| Broome, WA | 17.96 | (High Humidity summer) | (Warm Winter | (warm temperature) |
| Orange, NSW | 33.28 | (warm temperature) | Mild Winter) | (Mild temperature) |
| Geraldton, WA | 28.78 | (warm temperature) | Mild Winter) | (Mild temperature) |
| Launceton, TAS | 41.43 | (Mild temperature) | (Cold Winter) | (Cool Temperature) |
| Orange, NSW | 33.28 | (warm temperature) | Mild Winter) | (Mild temperature) |
- Passive design strategies
| City | Design Strategies |
| Toowomba, QLD | · use of Natural Ventilation, use of electricity and air HVAC system, basement |
| Katherine, NT | · use of Natural Ventilation, use of electricity and air HVAC system |
| Mannum, SA | · use of Natural Ventilation, electric heaters, solar energy |
| Broome, WA | · use of Natural Ventilation, use of electricity and air HVAC system |
| Orange, NSW | · use of Natural Ventilation, electric heaters, solar energy |
| Geraldton, WA | · use of Natural Ventilation, coolers, solar energy, basement |
| Launceton, TAS | · use of Natural Ventilation, electric heaters, solar energy |
| Orange, NSW | · use of Natural Ventilation, electric heaters, solar energy |
Assessment Sheet Thermal Comfort References
OLeary, T. Introducing 2nd generation NATHERS thermal modelling software to building and construction programs at UniSA in 2008/2009 (1st ed.). School of Natural and Built Environments, UniSA.
Nicol, F., Humphreys, M., & Roaf, S. (2012). Adaptive thermal comfort (1st ed.). London: Routledge.
Reynolds, M. (2000). Comfort in any climate (1st ed.). Taos, NM: Solar
