Keep the building warm in the winter and cool in the summer
with little to no utility bills / fossil fuels.
This increases both psychological and physiological comfort.
Both the International Building Code and the International Residential Code have requirements for maintaining a minimum temperature in buildings. They do not have requirements for a maximum temperature in buildings though there are ventilation system requirements and there are reasonable standards for comfort.
“All design projects should engage the environment in a way that dramatically reduces or eliminates the need for fossil fuel.”
The 2010 Imperative, Edward Mazria,AIA, Founder of Architecture 2030
Passive solar technologies absorb heat from the sun via thermal mass (water, rock, stone, mud, etc.), cause ventilation via cooling tubes and operable windows with little use of any electrical energy.
Every south-facing window creates a direct-gain system, while windows facing east, west, and north lose more heat than they gain in the winter. The greenhouse effect, acts as a one-way heat valve. It lets the short-wave solar energy enter but blocks the heat from escaping. The thermal mass inside the building then absorbs this heat, both to prevent daytime overheating and to store it for nighttime. The proper ratio of mass to south-facing glazing is important.
Since in direct gain the building is the collector, all contents, such as the drywall, furniture, and books, act as thermal mass. However, the contents are usually not sufficient to store an adequate amount of heat without additional thermal mass. When there is no concrete floor or when even more thermal mass is desired, it can be provided in the walls, water containers, floors, or phase-change materials.
Although solar heat can be supplied by convection to the rooms on the north side of a building, it is much better to supply solar radiation directly by means of south-facing clear-story windows. Besides bringing warming sunlight further into the building, clear-stories also provide excellent day- lighting, because light from above is best.
Most direct-gain systems consist of straight walls facing due south or as close to south as possible. Direct gain is the most efficient when energy collection and first costs are the main concerns.
A Passive House / Building is a building standard that is energy efficient, comfortable, affordableand ecological ALL at the same time.
Passive House / Building is not a brand name, but a construction concept that can be applied by anyone and that has stood the test of practice and literally thousands of years of time. These are modern, beautiful, high-value homes.
Passive Buildings allow for heating and cooling related energy savings of up to 90% compared with typical building stock and over 75% compared with average new builds. In terms of heating oil, Passive Houses use less than 1.5 litres per square meter of living space per year – far less than typical low- energy buildings. Similar energy savings have been demonstrated in warm climates where buildings require more energy for cooling than for heating (thermal mass).
Passive Houses are also praised for their high level of comfort. They use energy sources inside the building such as using the heat from an oven or solar heat entering the building – making heating a lot easier.
Appropriate windows with good insulation and a building shell consisting of good insulated exterior thermal mass walls, roof and floor slab keep the heat during winter in the house – and keep it out during summer.
Ventilation consistently supplies fresh air making for superior air quality without causing any unpleasant draughts. This is a guarantee for low Radon levels and improves health conditions.
FAQ: Heating and Cooling Buildings
- What is a Passive Building?
- A Passive Building is a structure designed to maintain a comfortable interior climate primarily through passive heating and cooling strategies, minimizing the need for mechanical systems. These buildings emphasize energy efficiency through elements like insulation, airtight construction, strategic window placement, and thermal mass.
- How does climate influence building design?
- Climate plays a crucial role in dictating suitable building designs. Factors like solar orientation, prevailing winds, temperature fluctuations, and humidity levels influence the selection of materials, building orientation, window placement, and shading strategies. For instance, in hot, arid climates, thick walls with high thermal mass help moderate indoor temperatures, while in humid climates, cross-ventilation becomes essential.
- What is thermal mass, and how does it contribute to energy efficiency?
- Thermal mass refers to the ability of a material to absorb and store heat energy. Materials like concrete, stone, or water act as thermal batteries, absorbing heat during the day and slowly releasing it at night. This process moderates temperature fluctuations, reducing the reliance on heating and cooling systems.
- What are Trombe walls, and how do they work?
- Trombe walls are passive solar heating systems that utilize a south-facing wall made of a dark, heat-absorbing material like concrete or stone. A layer of glass or glazing is installed a few inches in front of the wall, creating an air space. Sunlight heats the wall, and the trapped air circulates heat into the building. Vents at the top and bottom of the wall can control airflow.
- How does the greenhouse effect contribute to passive heating?
- South-facing windows function similarly to greenhouses, allowing short-wave solar radiation to enter but trapping the longer-wave infrared radiation emitted by heated surfaces inside. This “greenhouse effect” passively heats the building during the day, and thermal mass materials store the heat for later use.
- What is the difference between R-value and U-value in insulation?
- R-value measures a material’s resistance to heat flow; higher R-values indicate better insulation. Conversely, U-value (or U-factor) measures heat transfer; lower U-values mean better insulating properties. Both values help assess the energy efficiency of insulation materials.
- What are earth tubes, and how can they be used for cooling?
- Earth tubes are buried pipes that utilize the stable, cooler temperatures of the earth to cool and dehumidify air drawn through them. As warm air flows through the tubes, it loses heat to the surrounding soil. The cooled air, often with reduced humidity due to condensation within the tubes, then enters the building, providing passive cooling.
- What are the advantages of using natural building materials like adobe or rammed earth?
- Natural building materials like adobe or rammed earth offer several advantages. These materials are often locally sourced, reducing transportation costs and environmental impact. Their inherent thermal mass properties contribute to passive heating and cooling, and they can create unique, aesthetically pleasing structures. Additionally, these materials are often more sustainable and healthier for occupants compared to some conventional building materials.
Tire Retaining Walls
The same method for building structural walls in buildings can be applied when building retaining walls made with rammed earth encased in steel-belted rubber. Depending on the load the retaining wall is retaining, the batter