Building Automation is Key
“Control, control, you must learn control!”
Yoda “The Empire Strikes Back”
The following is an excerpt from the second edition of “How to Future Proof Your Home.”
Until now we have talked about building efficiency into the home. Unfortunately unconscious human behavior can completely undo a good design through careless use or through lack of attention when inhabiting a home. An energy conscious user on the other hand can accentuate the design through understanding how energy and water are used and by adjusting their behavioral patterns for conservation. The cost this of this awareness is zero dollars, making it the cheapest way to reduce your utility bills.
Conscious energy usage is the most important component regarding efficiency that humans have control over after a building is built. Once built, ensuring that the systems are performing optimally is of prime importance. For instance it makes no sense to have both the heating and cooling on in the same zone at same time[i]. It’s also equally silly to have heaters operating right next to an exterior door that is propped open; as is often the case in some retail establishments[ii]. Another example is having lights on when a room or area is not in use. These are simple and common examples of wasting energy that are unconscious behavioral patterns in some people.[iii]
Once the human factor is eliminated, proper control of mechanical heating, cooling and ventilation systems is key with regard to the energy efficiency of homes. This is where automation via a thermostat comes in. In a home, traditional automation is relatively simple.
A thermostat will turn the required system – usually a furnace or air conditioner – “ON” when necessary and turn it “OFF” when unnecessary. Older thermostats have a setpoint which is continually measured by the device. Once a certain threshold is exceeded on a thermostat, the device sends a signal to equipment in order to activate the equipment. Traditional thermostats are continually operating on a single setpoint that doesn’t change until a user adjusts it.
A programmable thermostat can be a very cost effective way of saving energy. A programmable thermostat allows for different setpoints at different times of day and days of the week. By programming internal temperatures to be closer to outside temperatures when people are sleeping or when people are at work, home owners can potentially slash hundreds of dollars off their bills. The dilemma for some people is that they don’t feel capable of programming their thermostat. So what should one do if this is the case?[iv]
Recent advances in technology have created smart products such as the Nest thermostat, a product that detects both noise and human movement and is connected to the internet. By knowing outside air temperatures and paying attention to the daily habitation patterns within your home, this technology can learn your routine in order to remove the need for programming your thermostat. This helps it learn the temperature dynamics of your home thereby reducing the energy usage of your heating and cooling system. These smart units are also very useful for cabins or other places that aren’t regularly occupied. With many products you can access them via your smart phone or through the internet and activate them so that it’s a comfortable temperature when you arrive.
In most homes there is only one thermostat controlling both the heating and cooling systems of the entire home. The problem with this is that often times areas are not being used yet the entire building is being heated or cooled. While a single thermostat is simple to set up, it is often wasteful, especially in larger homes or buildings. The solution is to have areas zoned according to their usage.
By having individual rooms or areas separately controlled, a greater degree of comfort and energy efficiency is achievable. This is because rooms that are unoccupied can have the heating or cooling turned down to save energy. This also helps in buildings where different rooms can be used for different things such as a kitchen or a common space. While automation and control does add a level of complexity and cost when first set up, it is often worth the expense and effort as the building gets larger. Note however that the closer the building is to passive house standards, the less necessary heating and cooling becomes and thus multiple zones are not always necessary. Thus the added investment in design, insulation and Windows reduce the need for spending money on complex heating and cooling systems.
[i] This doesn’t happen that often in a home unless the heating and cooling systems aren’t linked together via a common thermostat. I’ve observed both heating and cooling systems operating simultaneously in commercial buildings, which is very costly for the owner. This often happens in offices where unbalanced or over-sized air conditioning is making staff cold causing them to plug in electric heaters. In certain situations such as a school or church, a large number of people are present and producing heat on a cold day. In these circumstances both heating and cooling systems may be working in the same building but they shouldn’t be working in the same zone at the same time. Optimally, useful heat generated from people or machines would be transferred to zones that require it using a heat pump system. This is not how most traditional designers think.
[ii] Think about how wasteful and unnecessary it is to leave a door open during cold temperatures to welcome customers in. Why not open the door for them instead or post a sign that informs the customer that “our door is closed for the environment but please come inside”? If you see this situation at your work or at a business that you frequent, why not bring this to the attention of a manager or person in charge? It will help them reduce their operating costs and be more environmentally friendly. It’s simply a shift in mindset that is required.
[iii] Brushing teeth with the water running, holding your door open and talking, leaving the fridge open to stare into or leaving it open while you prepare food or pour drinks are other examples of people unconsciously wasting energy.
[iv] Get a younger person to do the programming for you or get a thermostat that is factory set with nighttime and daytime setbacks.