Warm and Fuzzy (Cold Wave)

 

When designing your home ambiance, the temperature should be a top priority. A house maintaining a temperature of 78°F during summer and 68°F during winter is considered a comfortable and energy-efficient home. 

By maintaining a comfortable temperature, we don't mean with the help of AC, furnace, and fireplace year-round, but rather a house designed and built so it can maintain comfortable temperatures with minimum dependence on cooling and heating systems.

Great ambiance and comfort can be achieved by investing in proper insulation, air tightening, and efficient HVAC solutions, which in return, also yield considerable financial savings. 

Such implementations will also transform your home into a more sustainable one: resilient in the face of extreme weather events and power outages, and eco-friendly with reduced/no negative impact on the environment.

 

Key strategies we will cover in this blog post:

• Building Envelope  
• Foundation, Wall, and Roof Insulation beyond code
• Air and Water Barriers
• Energy-Efficient Windows
• Roof Design
• Passive design (see our “passive house” blog for further details)
• Energy Management Systems
• Energy/Environmental Modeling 

 

Outside Temperatures and Your Home - A Refuge From Extreme Weather

Climate change is usually associated with increasing temperatures and an increase in extreme weather events. Yet, North America has experienced increasingly frequent extreme cold winter weather over the past four decades. In February 2021 a severe cold wave hit large parts of North America, from Canada to Northern Mexico. 10 million people were left without power and more than 125 people died in Texas alone.

A study suggests that extreme cold weather events could be attributed to arctic warming.

According to the U.S. Department of Health and Human Services Centers for Disease Control and Prevention (CDC), extreme cold temperatures can lead to hypothermia and frostbite, which may lead to several health consequences, including death. The U.S Department of Homeland Security's Ready, adds the health risks of potential carbon monoxide poisoning, and heart attacks from overexertion. 

Whether you are designing a new home or renovating your existing one, there are many solutions that you can adopt to reduce the risks of extreme temperature events and can improve the overall resilience of your home to better cope with extreme climate conditions. Although overall temperatures are increasing, our homes should be designed for a greater range of temperatures to withstand increasing extreme cold events. 

Note: we are covering the fundamentals of a few strategies and provide pointers to some solutions that are available in the market, but, by no means, is this an exhaustive list. There are many more products and solutions out there.

 

Building Envelope 

Foundation, Wall, and Roof Insulation beyond code

Proper insulation of crawl spaces/basements, walls, and the roof of a building help mitigate the risk of overcooling by reducing conductive gains through the envelope and roof. 

Insulation has many advantages beyond making occupants more comfortable, such as: improving air quality, reducing outside noise, saving energy with direct returns on your investment through substantially lower energy bills, as well as an appreciation of your home value.

There is also a green angle, well, actually two. First, the reduction of energy use will lower the impact of your home on the environment. Second, some of these insulation solutions are made of green materials and processed in a sustainable fashion, which means you can further reduce the impact of your home on the environment, not to mention, improve the overall health of your home’s occupants by not using chemicals or other health-hazardous materials.

One of the Resilient Design Institue helpful recommendations in the aftereffect of the Texas cold snap in 2021 in order to prevent utility pipes from freezing, the pipes should be kept within the building’s insulated envelope.

Some of the best green and resilient insulation materials are cotton, castor oil-based, soybean-based foam, and sheep's wool insulation. 

Top manufacturers of such solutions can be found in Home Depot, Lowes, Amazon, and local shops (which we support!). They are:

• Rockwool is one of the leading and top-quality manufacturers of wool-based insulation solutions.
• Huntsman (previously known as Demilec) makes some of the best Bio-based foam insulation solutions.
• Bonded Logic makes some of the most advanced cotton-based insulation materials.

 

SPOTLIGHT: Blue Jeans Go Green program is a non-profit organization that collects denim (made from cotton) and recycles it back into its natural fiber state and transforms it into something new - insulation. They have teamed up with Bonded Logic and a portion of their UltraTouch™ product is contributed to Habitat for Humanity affiliates and other building organizations.

 

Air and Water Barriers

The exterior of the building should have a continuous weather barrier to prevent water and wind from blowing into the wall cavity to prevent mold and mildew problems and allow the effectiveness of the thermal insulation.

The Cold Climate Housing Program of the University of Minnesota emphasizes that a continuous air barrier on the warm side of the components of building envelope is essential to hold in the conditioned air and prevent moist air from entering the structural cavities to avoid condensing on the exterior building components.

A vapor barrier should be placed on the warm side of the building to keep the insulation and structural cavities dry.

The Building Science Corporation stresses the need for a perfect air barrier and a perfect vapor barrier to prevent moisture flow by air leakage and vapor diffusion from the inside to the outside.  The vapor barrier should be able to prevent even tiny gaps from leading to icicles and frost boles. 

 

Energy-Efficient Windows

According to the Cold House Climate Research Center, in a cold climate, it is important to install energy-efficient, Low-E, triple-pane insulated windows with high R-Values to feel comfortable and to prevent heat loss through the windows.

When it comes to thermal performance, the weakest part of the window is the frame. Materials like wood, vinyl, and fiberglass frames conduct less heat than metal frames.

The National Fenestration Rating Council (NFRC) evaluates windows for overall thermal performance (U-factor), heat transmission from sunlight (Solar Heat Gain Coefficient), and air leakage (AL). The Fenestration & Energy Industry Alliance (AAMA) and the Attachments Energy Rating Council (AERC) also provide certifications for the energy performance of residential windows. 

The most important factor to look at is the U-factor. Opposite to high R-Values, in U-factor, we look for the lower numbers. In a climate like Alaska look for a U-factor of 0.25 or less.

Aside from the type and quality of the window itself, it’s important to weatherize it properly with at least dual continuous weather strips, to make sure of proper airtightness.

Lastly, proper installation is key for the window to work. Windows need to be sealed tightly within their frames and to the building structure. Preserving the integrity of your home’s vapor barrier, insulation, and exterior finish is critical when installing windows.

 

Roof Design

According to the Cold House Climate Research Center, “a properly constructed “cold” roof maintains a continuous air space between the underside of the roof and the insulation”.

New Home Source specifies recommendations for the roof design for extreme cold events:

• The roof should be steeply sloped to allow snow and water to shed quickly, such as a standard gable. 
• Choose roofing materials that shed snow easily (unlike slate and wood). 
• Reduce roof openings. Vents and chimneys should be placed near the roof ridge or peak. 
• The roof edge should have an ice shield membrane.

 

 

Passive Design:

Passive House Institute (PHI) defines a passive house as a “building standard that is truly energy-efficient, comfortable, and affordable at the same time. Passive House is not a brand name, but a tried and true construction concept that can be applied by anyone, anywhere.”

In other words, a passive house is a design and construction of a house that eliminates the need for an active heating or cooling system. A passive house will maintain the best comfort for its occupants by keeping the house cool on the inside during summer, and warm during winter without the use of HVAC systems. In addition, a passive house will provide its occupants with fresh, healthy air.

On top of its efficient, environmentally friendly attributes, we consider its passive design to be a resilience strategy. The ability of such a design to provide an alternate, passive form of space heating and cooling in the event of a power outage, eliminates the reliance on the electrical and natural gas grids. This is a fundamental strategy for homes in risk zones with extreme weather events where power outages occur while the outside temperatures and/or air quality are hazardous. 

Passive design is achieved by implementing several solutions: tight insulation, airtightness, ventilation, windows location, materials, and thermal bridging. It is very challenging to retrofit an existing house to become truly “passive”, however, adopting these solutions can yield a safer, more resilient house, amid power outages and extreme weather conditions.

To further learn about the passive house method, check our blog here: “What is a Passive House”.

 

 

Energy Systems

The strategies for climate change adaptation in this section focus on:

• Improving the performance of building mechanical and electrical systems to respond to temperatures
• Improving the efficiency of building mechanical systems to allow increases in capacity without reducing total performance

The size of an HVAC system, and its associated energy use, are estimated using data that provides various annual climate averages based on past weather data. 

Designing HVAC systems based on historic weather data will make building systems vulnerable to future changes in climate. 

 

Energy Management Systems: 

Energy management is a strategy mainly utilized by businesses and managers of commercial buildings that leverage solutions to monitor, control, and optimize energy and ambiance. Energy management and control systems can reduce the energy use of systems in buildings and homes. 

By comparing data from these systems against weather data, building managers may be able to anticipate when changes in mechanical system design or operation are necessary. These systems also have the potential for allowing demand-side management and demand-response to interact with smart grids. Energy management can include start/stop functions, temperature setback/setup, and economizer controls.

In recent years, with the advancement of technology, we have seen an increase in the adoption of energy management solutions inside residential homes. These systems are also known as HEMS (Home Energy Management Systems) or SHEMS (Smart Home Energy Management Systems). The road to a fully equipped and connected smart home where occupants can monitor, control (or have auto control), and optimize the ambiance and energy utilization is still in its infancy. 

From smart connected thermostats and appliances to solar panels and energy storage solutions, an advanced HEMS can help occupants predict their home's energy consumption, better manage and control their costs and environmental impact, change how they interact with the local energy grid, and allow them to plan how to live more comfortably within their home.

Here is a good read from the National Renewable Energy Laboratory (NREL), which explains how an advanced HEMS solution would work. 

To read more about best practices for heating your house, please check out this page on the Energy.gov website.

 

Energy/Environmental Modeling: 

This strategy is used to model changes in temperature and precipitation to better understand the effect of climate change on building systems. Advancements in climate models, building energy models, and other environmental modeling tools can help determine the size of building equipment for projected changes in temperature and precipitation levels. 

Energy and environmental modeling is a complex and highly technical subject, therefore, is mainly adopted in commercial and industrial buildings. However, if you are properly designing a new home or renovating your current one, as a minimum, it is good practice to hire a specialist to run an energy audit for your home. In such an audit, an expert can analyze and suggest passive solutions, insulation, and energy management solutions as well as run simple, or advanced, energy models to better plan, for example, your HVAC system. 

For further reading, you can tap into About Building Energy Modeling

 

Final Thoughts

Extreme temperatures impact the comfort and well-being of household occupants, and in some cases may lead to illness and even death. A home maintaining a temperature of 78°F during summer and 68°F during winter is considered comfortable and energy-efficient.

By incorporating climate-resilient design strategies for cold climate and investing in good insulation, air tightening, and efficient HVAC solutions that will make your house energy-efficient, you can feel warm and fuzzy, acheive protection from extreme weather events, and considerable financial savings, while reducing the negative impact on the environment. This is what we call a truly sustainable home.

Key strategies covered in this blog:

• Building Envelope  
• Foundation, Wall, and Roof Insulation beyond code
• Air and Water Barriers
• Energy-Efficient Windows
• Roof Design
• Passive design (see our “passive house” blog for further details)
• Energy Management Systems
• Energy/Environmental Modeling 

 

KEEP COOL. BUILD RESILIENCE. EAMPACT.