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Using notes and freehand sketches, discuss the importance of any two of the following in Passive House design: - air tightness - indoor air quality - solar shading - Leaving Cert Construction Studies - Question 10 - 2017
Question 10
Using notes and freehand sketches, discuss the importance of any two of the following in Passive House design: - air tightness - indoor air quality - solar shading.... show full transcript
Worked Solution & Example Answer:Using notes and freehand sketches, discuss the importance of any two of the following in Passive House design: - air tightness - indoor air quality - solar shading - Leaving Cert Construction Studies - Question 10 - 2017
Step 1
Discuss the importance of air tightness in Passive House design
Answer
Air tightness plays a crucial role in Passive House design by preventing air leakage and ensuring the integrity of the building envelope. By maintaining an airtight structure, the internal environment is protected from external air infiltration, which can lead to significant energy loss.
Furthermore, a well-sealed building minimizes mechanical load on heating and cooling systems, which enhances overall energy efficiency. Effective air tightness can also help to reduce drafts and maintain a comfortable indoor temperature. It is essential for air tightness measures to be installed correctly, as insufficient sealing can lead to cold spots and undesirable air movement.
The standard for air tightness in Passive Houses is typically less than 0.6 air changes per hour, ensuring a high level of thermal comfort and air quality.
Step 2
Discuss the importance of indoor air quality in Passive House design
Answer
Maintaining excellent indoor air quality (IAQ) is vital in Passive House design, primarily accomplished through mechanical ventilation systems. Systems like Mechanical Heat Recovery Ventilation (MHRV) ensure the consistent circulation of clean, fresh air within the living spaces.
Typically, these systems filter incoming air to remove pollutants, allergens, and moisture, promoting a healthy indoor atmosphere. The goal is to achieve a balanced relative humidity (approximately 30% to 60%), which prevents issues such as condensation and mold growth. Additionally, adequate IAQ is vital for the well-being of inhabitants, as poor air quality can cause health issues and discomfort.
Incorporating good ventilation strategies while also addressing external pollutants can significantly enhance overall indoor conditions.
Step 3
Draw a line diagram of the given room layout and show a typical design for the ducting to the MHRV unit.
Answer
The line diagram should include all relevant rooms and indicate the positioning of the MHRV unit as shown in the ground floor plan. Typical ducting should be illustrated to connect the MHRV unit to various rooms, particularly focusing on areas like kitchens and bathrooms where humidity tends to be higher. Ensure the diagram includes arrows to indicate airflow direction through the ducts.
The MHRV system works by taking stale air from wet areas, such as kitchens and bathrooms, and passing it through a heat exchanger where it pre-heats incoming fresh air. This process not only improves energy efficiency but also ensures adequate ventilation throughout the residence.
Step 4
Discuss two advantages of siting the MHRV unit in the hallway, as shown.
Answer
Locating the MHRV unit in the hallway offers several advantages. Firstly, it is positioned on an external wall which allows for the direct extraction of exhaust air, minimizing duct lengths and potential heat losses. This convenient positioning also simplifies maintenance access to the unit without disrupting the internal living spaces.
Secondly, placing the MHRV unit in the hallway keeps it away from bedrooms and living areas, reducing noise and visual impact. This location also potentially enhances the effectiveness of the ventilation system by allowing for better air distribution throughout the home, improving both air quality and occupant comfort.