14 Jan Seaweed to Spray Foam
The focus on energy efficiency of our homes has certainly grown by leaps and bounds over the past 50+ years, resulting in the National Building Code now having an extensive section devoted to the energy performance of homes. The following is a brief discussion of some of these advances, however, I recommend doing some research and contacting organizations like Efficiency Nova Scotia to learn more about how to improve your home’s energy efficiency.
Insulation – The majority of homes built prior to 1960 had minimal or zero insulation, some filled their walls with a bagged, dried seaweed insulation which was a ‘made in the Maritimes’ solution. When I was a boy, I recall local fisherman would haul seaweed from the shore and place it around their home to keep the wind and cold out. Others used scrap cloth to keep out drafts or to seal between the cold basement and the main living area. We have seen the evolution of insulation from seaweed to fiberglass batt, blowen in cellulose and fiberglass, ridged foam insulation, and introduction of vapour barriers and building wrap to significantly reduce air movement through the walls. Now, we see more and more use of spray foam insulation and homes being designed that are so well insulated that they meet “net zero” energy requirement. “Net zero” is an interesting topic that has evolved, if you are interested in learning more, please do a little research, as I believe it is the building gold standard for all future homes.
Windows & Doors – Another area of advancement has been on windows and entry systems. We love our big, beautiful windows, with lots of glass, however they are still one of the largest sources of heat loss and gain. Not that long ago, a single pane glass window, with a storm window was considered ‘high tech’, however, many people can still recall these windows would actually frost up in the winter! They had zero insulation value and were the equivalent of a hole in the wall of your home. In the 1960s and 1970s, windows started to advance with vinyl windows, better glass, double and triple thermal panes, adding seals around the windows, and improving installation methods. Even with that, a typical double thermal pane window today would achieve an R-value of 3-5. With a top-notch triple pane window with Low-E filaments and improved gas fillings between the panes, we can see windows with an R-value of 7-8. To give perspective, the requirement for a wall is R-24 and the attic is R-50. Therefore, even with the advancements of window in the past 50+ years, they are still a challenge for energy efficiency in our homes.
Heating and cooling systems – The heating of a home in a cold climate can be a significant operating cost for a home, which is why we have seen significant changes in these systems over the decades. Fireplaces and wood stoves were often the only source of heat in older homes and are still in use today, less often as a primary heating source. However, with the lack of insulations, it would be very difficult to keep all rooms warm and is often the reason you see so many doors in older homes which were used to preserve heat in the living areas. Central heat systems followed and are still in use in homes today. Typically, a central boiler was fuelled by coal and would heat wate which in turn would be circulated around the home to cast iron rads to radiate heat in each room. These were effective but they did take up space, could become very hot, and were not always the most efficient. There was a shift to oil fired hot water or forced warm air in the 1960s and 70s, however, this came with the on-site storage of oil and potential environmental hazards due to leaks. Today, we are seeing more homes heated with heat pump technology, which also provide cooling in the summer. This duel technology can be a bonus with more extreme weather due to climate change. These units typically operate on electricity and can be air to air systems or air to water system combination. We are also seeing a lot of on demand hot water boilers to supplement the heat pump during the coldest days of the winter and provide domestic hot water. With continuous improvement on renewable energy sources such as solar panels and operating systems, we are seeing these systems used more frequently for supplemental and primary heating.
Ventilation – With home being made more air-tight with better insulation, the need for air handling systems has become critical. These systems can be used to exchange the warm moist air inside the home with cooler dryer air from outside. This is completed through a heat exchanger and allows some warming of the cooler outside air. Air exchange is critical to maintaining healthy air quality within the home and control the humidity of the home. This can reduce condensation on windows and the expansion and contraction of wood floors, cabinets, and furniture. Older homes were not built with ventilation systems and when they are renovated and made more air-tight, it is important to consider the addition of an air-exchange unit.
I know that this is a lot to take in and it only scratches the surface! It’s important to note that with climate change and increased fuel costs, more energy efficient homes are critical as we move forward. The innovation and implementation of alternative heating and cooling are on the rise and I’m excited to see what’s next. I hope you have found this article helpful and potentially sparked your interest to learn more on how to improve the energy efficiency of your own home.
Dan Monk, P.Eng. / Red Seal Carpenter
Owner – MONK Renovations