The building envelope (aka shell or skin) refers to the components separating the interior from the exterior:
It is important to keep the internal climate comfortable from changing external weather, the 'thermal mass' of the building enables it to store heat, providing inertia against the temperature fluctuations. This is achieved by durable continuous air-tightness and insulation protection.
A well-established thermal envelope with ensure:
o Reduced air flow between the outside and inside of the home
o Slowed movement of heat
o Controlled movement of moisture
Commonly the air leaks that allow heat to escape in a home:
o Ceilings & attics
o Basement & crawlspace
o Doors & windows
o Open vents: bathroom, kitchen, laundry
o Electrical outlets
As cold outside air infiltrates openings the absolute amount of moisture (water vapour) contained is low and will cause the air in a heated room to feel dry.
See: Air Infiltration and Exfiltration ↗ & Moisture Intrusion ↗
An airtight home would ideally not require a humidifier, and generate the needed moisture make-up from cooking, bathing & dishwashing. However, the concern would be inside air quality of trapped humidity, fumes, odours and gases. A mechanical ventilation system with circulated fresh air would provide the remedy.
About 60% of your home’s (residential) energy use goes to space heating.
When endeavoring on a home project the most impact for energy efficiency and conservation lies with improving the airtight construction, higher levels of insulation, energy efficient doors & windows, efficient heating systems, and heat-recovery ventilators (such as R-2000 homes ↗ which surpass the basic Building Code requirements).
Passive House Overview ↗ & Thermal Protection ↗
Use passive heat sources: human occupants, indoor appliances, and optimized heat use from the sun
Provide constant fresh air and retain heat by using heat recovery ventilation systems
Super insulating the building envelope and minimizing thermal bridging
Energy Star products ↗
Testing and certification to meet stringent energy efficiency standards for appliances, HVAC, water heaters, lighting, electronics, windows and doors
Compare how much energy a product uses compared to similar models using EnerGuide ↗
Guides: Home Energy Guide by MN Power