Energy efficiency is a good thing, right? For as long as I can remember, I’ve associated energy efficiency with positive connotations. I have felt a level of satisfaction when choosing an energy efficient appliance. However, my latest explorations are causing me to question our singular focus on energy efficiency.
I recently joined a company who focuses on making indoor spaces healthier and more comfortable. One of the best things about starting any new job is the learning curve. I am always happiest when learning, and this subject matter is particularly interesting. I am playing with all sorts of sensors: temperature, pressure, humidity, carbon dioxide, particulate matter (i.e. dust), volatile organic compounds (i.e. chemicals in the air), and more. Its fascinating to actively monitor data for the indoor spaces where I spend time. And this is where things are getting interesting.
You see, last year my family completed construction of our new home. We built this home to modern construction standards. We have a highly insulated home, with energy-efficient doors and windows. We had a local energy authority come to our home to meticulously address any potential air gap. And we are reaping the financial rewards for our energy-efficient masterpiece, with eye-opening savings on heating and cooling bills.
Fast forward to my current fun with sensors. I am discovering that there are particulate matter and volatile organic compounds in the air in our home. This is completely natural. There are by-products from the combustion of fossil fuels for heating and cooking; there are off-gasses from building materials, carpeting and furnishings; there are volatile organic compounds from the use of cleaning products and cosmetics. These particulate matter and volatile organic compounds are all around us. However, I’m discovering that during winter time the opportunities for these particulate matter and volatile organic compounds to escape from my home are limited. After all, it is not practical to open windows when the outside temperatures are so low. So this air is circulating around my home, and the concentrations of harmful matter are only increasing over time.
I appreciate the energy efficiency of our home. I appreciate the energy efficiency of our Heating, Ventilation, and Air Conditioning (HVAC) unit. The manufacturer of our HVAC unit, encouraged by public policy, has invested significant amounts to create the most energy-efficient unit they can. Of course, it is more energy efficient for them not to pull in outside air during heating and cooling cycles. If they do pull in outside air, their units will have to do more heating in winter and more cooling in summer because of the temperature difference of the outside air. Therefore, these manufacturers focus on essentially recycling my indoor air. They do filter the air, before it enters the HVAC unit, but how effective is this filtering?
This is particularly concerning when you consider how much time we spend indoors. We spend a considerable amount of time in our homes, and when we're not at home we are in workplaces, or schools, or threaders, or stores, or other indoor spaces. In fact, the Environment Protection Agency (EPA estimates that an average American spends 87% of their time indoors. Furthermore, EPA studies show that indoor air pollution levels are typically between two and five times greater than outdoor pollution levels. Yes, you read that correctly… our indoor air is between two and five times more polluted than our outdoor air.
I have learnt that commercial indoor spaces often handle this better than residential indoor spaces. Many commercial spaces actively pull outdoor air into their heating, cooling, and air conditioning systems. However, many residential systems, at least in part driven by a desire to be as energy efficient as possible, simply recycle existing indoor air, making our homes less and less healthy during seasons when opening windows is not practical.
Conor O’Mahony is head of product at ConnectM Technologies. The ConnectM Aurai cloud platform makes it easy to perform advanced data science and machine learning on readings from a wide variety of indoor climate and air quality sensors.