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10. (a) Using notes and freehand sketches, discuss in detail the importance of any two of the following in the design of a Passive House: • building form • indoor air quality • foundation design - Leaving Cert Construction Studies - Question 10 - 2014
Question 10
10. (a) Using notes and freehand sketches, discuss in detail the importance of any two of the following in the design of a Passive House: • building form • ind... show full transcript
Worked Solution & Example Answer:10. (a) Using notes and freehand sketches, discuss in detail the importance of any two of the following in the design of a Passive House: • building form • indoor air quality • foundation design - Leaving Cert Construction Studies - Question 10 - 2014
Step 1
Using notes and freehand sketches, discuss in detail the importance of building form in the design of a Passive House.
Answer
Building Form
The building form in a Passive House plays a crucial role in energy efficiency and thermal performance. The following points illustrate its importance:
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Simplicity of Design: Simpler forms reduce the surface area and, consequently, heat loss. Optimizing the shape helps in minimizing construction costs and maximizing the energy performance ratio.
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Orientation: The form should be designed considering the sun's path, allowing for optimal solar gain in winter and minimizing it in summer. This is crucial for passive heating and cooling strategies.
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Material Efficiency: A well-formed building allows for the use of materials that enhance thermal insulation, ensuring that the internal environment remains comfortable irrespective of external conditions.
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Ventilation: Building form affects how natural ventilation flows through the structure, which is vital for maintaining indoor air quality without excessive energy use.
Step 2
Using notes and freehand sketches, discuss in detail the importance of indoor air quality in the design of a Passive House.
Answer
Indoor Air Quality
Maintaining good indoor air quality is essential in a Passive House. Here are key aspects of its importance:
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Health and Comfort: Proper ventilation flushes out pollutants, reducing the risk of respiratory ailments and ensuring occupant comfort. This is especially critical in airtight buildings, like Passive Houses, where fresh air flow must be carefully managed.
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Energy Efficiency: Effective indoor air quality management relies on systems like Mechanical Ventilation with Heat Recovery (MVHR), which allows for energy-efficient air exchange without heat loss.
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Humidity Control: Good air quality controls moisture levels, preventing mold growth and structural damage. Adequate ventilation ensures humidity is maintained at optimal levels.
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Material Selection: Using low-VOC and sustainable materials contributes significantly to a healthier indoor environment, essential for occupant well-being.
Step 3
Using notes and freehand sketches, discuss the importance of orientation in the siting of a Passive House. Show the sun path in your sketch.
Answer
Importance of Orientation in Siting
The orientation of a Passive House is a critical factor influencing energy efficiency and occupant comfort. Key considerations include:
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Solar Gain: South-facing facades maximize solar gain during winter, reducing heating demands. The site should be analyzed to minimize shading from surrounding objects.
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Wind Exposure: Proper orientation considers prevailing winds, aiding in passive cooling strategies during warmer months. Shielding from strong winds can reduce heating requirements in winter.
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Daylight Utilization: Positioning windows strategically enhances natural daylighting, reducing reliance on artificial lighting.
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Seasonal Variation: The orientation must adapt to seasonal changes in solar path to balance heating and cooling needs throughout the year.
Sketch: A diagram showing the sun path indicates optimum angles for window placement and overhangs, enhancing energy efficiency.
Step 4
Discuss two reasons why overheating occurs and, using notes and freehand sketches, show two design details that would reduce the possibility of overheating.
Answer
Reasons for Overheating
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Excessive Solar Gain: During summer, if building forms and openings are not designed to limit solar gain, the house can become excessively warm. Poor window placement or lack of shading devices exacerbates this issue.
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Ineffective Ventilation: Inadequate ventilation strategies can lead to heat accumulation, particularly when the building is tightly sealed.
Design Details to Reduce Overheating
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Adjustable Overhangs: Incorporating adjustable overhangs allows for controlling sunlight entry; they can block high summer sun while permitting lower winter sun.
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Thermal Mass: Using materials with high thermal mass helps regulate internal temperatures by absorbing heat during the day and releasing it at night, lowering peak temperatures.