In this article, we provide information regarding passive design strategies, particularly for cold climates.
According to the World Health Organisation, if you live in a home that regularly dips below 18° Celsius you:
What are Passive Design Strategies?
Passive design strategies involve utilising the natural environment to regulate a building’s heating, cooling, ventilation, and lighting.
Rather than depending on mechanical systems like active design strategies, passive approaches harmonise with the local climate to ensure a pleasant indoor temperature.
Passive Design for Sustainability
Passive design strategies leverage the climate, site conditions, materials, and techniques to develop buildings that work in sync with the environment.
Architects and Building Designers make use of natural resources to craft indoor spaces that are comfortable while reducing dependence on mechanical systems.
Benefits of Passive Design
The design approach offers cost-effective, reliable, versatile, and energy-efficient building design solutions for clients.
- Passive design strategies reduce energy consumption, leading to decreased greenhouse gas emissions and a smaller carbon footprint. This is achieved by utilising natural resources to regulate temperature and light levels, reducing the reliance on artificial heating, cooling, and lighting systems.
- Passive design strategies can enhance occupant comfort and well-being. For instance, natural ventilation can improve indoor air quality, while daylighting can boost the quality of light, benefiting mental and physical health.
- Passive design strategies can help in cutting building operating costs in the long run. They require less maintenance than active systems, resulting in lower utility bills.
- Implementing passive design strategies can assist buildings in attaining mandatory sustainability certifications, meeting government regulations and standards whilst ultimately boosting their market value and appeal.
Design Challenges in Cold Climate
Designing for frigid environments poses unique challenges.
A flawed design could result in a very cold living space, condensation on walls, paint deterioration, and other issues. Therefore, utilising appropriate passive design techniques is crucial for successful cold climate design. Before delving into the passive design solutions, let’s examine the ‘attributes of cold climates’ and define the issue at hand.
Some attributes of cold climate that designers must consider include:
- Architects must ensure proper insulation in buildings to sustain a comfortable indoor temperature.
- Utilising passive design strategies such as building orientation and window placement can further enhance temperature regulation.
- Cold climates can be categorized into two types: dry cold and humid cold.
- While designing, it is crucial to consider these distinctions.
Precipitation (rain and snow):
- In many cases, colder climates often bring heavy rain and snow. Designers need to ensure that their roofs can bear the added weight of snow and handle potential leaks.
- Locations experiencing strong winds usually require wind barriers and buffers to minimize wind pressure.
As these characteristics can vary from one site to another, it is also important to understand the building’s micro-climate.
- Microclimate pertains to the specific climate of a particular site or area.
- It encompasses any local differences from the climate of a broader region or zone.
Passive Design Strategies for Cold Climate
There are several passive design strategies that Architects and Building Designers should consider when designing for cold climates. Below are just a few:
It is essential to maximise sun absorption for optimal thermal comfort in colder regions. Therefore, it is imperative that the project is positioned to harness sunlight efficiently throughout both summer and winter seasons.
Improve Heat Gain
One key strategy for designers to combat low temperatures is optimising heat absorption on the southern side during daylight hours. Passive systems harness and distribute heat naturally without mechanical intervention.
Ways to Achieve Heat Gain:
The primary and most effective passive heating method utilised in cold regions involves direct gain. This technique operates on the fundamental principle of allowing sunlight to enter living areas through openings or glazed windows.
In indirect gain, sunlight strikes a different surface, and the absorbed heat energy is then conveyed into the primary space. An instance of this is masonry walls that absorb sunlight and transfer the accumulated heat into the interior.
Isolated gain is focused on gathering heat in an area that can be isolated from the rest of the structure. Sunrooms serve as a great example of this technique.
Air sealing plays a crucial role in blocking cold air from entering buildings as well as stopping warm air from seeping out.
- Buildings with significant air leakage need additional HVAC systems to maintain a comfortable indoor environment.
- Implementing proper air sealing is a cost-effective strategy to reduce heating expenses, enhance durability, and enhance overall building comfort.
- This technique aids in regulating temperature, managing airflow, controlling vapor, and handling bulk moisture within the structure.
Thermal mass is the ability of a material to absorb and store heat energy.
Designers adjust the thermal properties of buildings to sustain comfortable internal environments while conserving material resources.
Thermal mass refers to a material’s capacity to soak up, retain, and emit heat. In regions with frigid climates and substantial heating requirements, incorporating high thermal mass can facilitate passive heating methods.
Other common materials used include concrete, bricks, and tiles. These materials have high thermal mass and can absorb and store heat during the day and radiate it out as the temperature drops in the afternoon throughout the evening.
In any household, windows play a significant role in both excessive heat gain and loss. Understanding the influence of the windows you choose is crucial.
To manage heat transfer through windows effectively, consider factors such as their size, height (as heat rises), advanced glazing and films, window shading, strategic shading during peak heat times, and the quality of their draught seals.
Good window design is integral not only to allowing sunlight into your home, but also to ensuring that it doesn’t escape. Carefully positioning and insulating thermal mass in your home will ensure that heat is collected, absorbed, stored and released the way you want it to be.
Good passive design should reduce or eliminate the need for additional heating or cooling depending on your location and often relies on an active occupant to work properly.
A passively designed home can deliver a lifetime of thermal comfort, low energy bills, and low greenhouse gas emissions, reducing one’s overall carbon footprint.