Energy Efficiency basics – How to be energy efficient at home

When it comes to energy efficiency, the most important thing to remember is, “not requiring energy is far more efficient than requiring it and using it sparingly.” While this is easier said then done in many cases, if planned out from the start, not requiring energy via the appliance, fixture or assembly in question can be rather cost effective. This is true even in the harshest climates.

How to be energy efficient without breaking the bank

Many people are under the false impression that if it is “green” than it is expensive. This is not true, especially when you consider that saving energy is equivalent to saving money. Since the price of fossil fuel energy used in the home is currently around record lows and isn’t going to be getting any cheaper, it makes sense that a home – which is at least a 50 year gamble on the price and availability of energy – is built with energy efficiency in mind. When it comes to building a home, the amount of energy that is used over the home’s  lifetime is essentially set in stone in the design stage, before the dirt is even turned. This is why best results are achieved when energy efficiency is planned from the beginning.

“Green” or energy efficient in a harsh climate such as found in Canada or the northern United States has a slightly different meaning then in most places. For instance I live in  Saskatchewan, which has a very harsh climate. By “harsh” I mean that the average year round temperature in Saskatoon is only 2.5 °C (36°F). Ouch! When you consider that we regularly see a few weeks a year where temperatures are in the 35°C range, the harshness refers both to hot and cold extremes. To survive in such a cold place we currently use mostly natural gas for our space and water heating needs and coal fired electricity for running our appliances. Because of this we have what the statisticians call a very high carbon footprint. Not surprisingly Saskatchewanians use the most energy per capita in Canada. This is why Saskatchewan makes a great test case when understanding how to build or renovate to be energy efficient. Luckily, if you understand how to cost effectively reduce your need for energy, being energy efficient is easy.

In terms of individual energy usage, most goes towards heating our homes.  So with this in mind, “green” in Canada and the northern United States comes down to three essential principles which are most cost effectively applied in this order:

1)    Reducing the need for energy in general.

2)    Reusing energy (in extreme climates).

3)    Generating or harvesting energy.

In Saskatchewan reducing the need for heating and cooling energy is much cheaper and easier than producing your own energy using renewable energy. In a home, the cheapest, easiest and most enduring opportunity for efficiency (and comfort) comes from isolating the usually cold outside from the warm inside on all exterior surfaces by “super-insulating” the structure. This can be accomplished via multiple methods to create a high R-Value wall assembly of at least R30[i]. Since heat rises, a significant proportion of the heat within most homes is lost through the ceiling, thus a high efficiency roof or ceiling is recommended to be at least R60. This can be accomplished using 24 inches of blown in cellulose or about 8.5 inches of closed cell spray foam. In order to achieve these high R-Values, thermal bridging (heat transfer) through low R-Value structural components (such as wood or metal studs) must be eliminated.

thermal bridgin wooden stud

This thermal-graphic (heat sensitive) image demonstrates how heat moves through a conventional 2×6 wooden wall stud. The purple lines show the temperature difference between the insulated wall cavity and the studs. It was 22°C inside and 5°C outside when this image was taken. Note that even the insulated R20 walls loose heat to the outside even at the mild outdoor air temperature of 5°C.

This is the same photo as above without the thermal graphic information.

Air tightness is essential for energy efficiency

While providing these high R-Value assemblies it is essential to ensure air tightness in order to reduce drafts via uncontrolled air infiltration. Drafts feel cold and are the main source of energy loss in buildings. Drafts are created when components don’t fit together correctly or aren’t properly sealed. They typically occur around windows, doors, vents and other protrusions in the building envelope. Ensuring air tightness has the benefit of reducing the likeliness of cold spots within the wall. Cold spots are highly undesirable as they are a breeding ground for mold growth.

Further efficiencies come by reducing the requirements for water heating (via low flow shower heads and aeration devices) and electricity usage (through energy star appliances and LED lighting). Notice how these efficiencies are easily achievable after the building is built.

Reusing energy is accomplished via methods such as heat recovery ventilators (which are essential in a super-insulated home) or through drain water heat recovery. Embodied energy[ii] from former building materials such as brick and wood can also be reused in a new building to add character and even reduce the cost of the project. If these materials are locally sourced, then the lack of energy needed for transporting them to the construction site gives you bonus green kudos.

A simple and very cost effective method of producing energy onsite is possible via implementing Passive Solar design creating a Solar home. Properly implemented passive solar design heats your home in the winter and keeps it cool in the summer for FREE. The best part about passive solar design (other than being able to sun bath within your home during the winter) is that all it takes to implement is awareness on the part of the designer, willingness to place more windows facing south, and a south facing lot (give or take 30 degrees from true south). If passive solar design is implemented, then storing heat energy within the home by implementing thermal mass is a very cost effective and usually easily implementable method of capturing and storing energy from the sun.

After the aforementioned efficiencies are implemented, it then becomes cost effective to really “go green” by producing or generating energy via the “sexy” renewable energy technologies such as photo voltaic panels (solar), solar thermal water heating, solar thermal air heating, wind turbines and ground source heat pumps – commonly called geothermal.

Implementing the three principles discussed in this post will not only reduce your energy costs and make your home more energy efficient, but it will be more comfortable, more valuable and even safer in the event of a winter emergency. You could say that implementing these solutions in your home make it truly Future Proof™.

Click here for Quick Facts about Energy Efficiency in Canada.

 

If your job is to help people save energy and improve the quality of buildings then why not tell people about it? Click here to register your business for free with FutureProofMyBuilding.com

 

Shane Wolffe is a professional engineer, accredited professional in LEED (leadership in energy and environmental design), certified energy auditor, and level one Thermographer. He is the author of “How to Future Proof Your Home: A Guide to Building with Energy Intelligence in Cold Climates”. To learn more, get involved and get part of his book for free visit www.FutureProofMyBuilding.com

 


[i] RValue is a measure of the ease at which heat migrates through a material from hot side to cold side. It is typically measured in RValue per inch of a particular material. Some experts believe our walls should be R50 for our climate.

[ii] Embodied energy is the energy that was used to create, harvest, transport and/or install a material or component. By reusing useful materials we are reducing the need to use energy to create new materials.

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