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Are Smart Thermostats as Smart as We Think They Are?

Updated: Nov 9, 2022

In 2019, smart home products began to take over the consumer market and had nearly one third of U.S. consumers installing them in their homes. If you are a homeowner, you may have considered implementing a smart thermostat into your home. They add a sleek, convenient element to a house in any room, allowing you to control it from anywhere. With thousands of different smart home products becoming more popular in the U.S., some people even model their entire house off a ‘smart home’, full of a variety of smart products that the owner can easily control.

Though smart thermostats like Nest, Wyze or ecobee may automatically adjust your heating/ cooling for you, they can be harmful and cause widespread energy-demand spikes, among other disadvantages. Because they can be set to the same schedule and can have the same settings at default, they can cause energy spikes at certain times of day if owners tend to use the default settings. There’s both benefits and negatives to the devices that work with the HVAC of the facility, house, or any space.

How do Thermostats Work?

Thermostats and HVAC units are directly connected in functionality. Because thermostats display room temperature, it generates signals to the HVAC system when there are changes in the temperature of the room to keep the temperature constant. Thermostats control whether the HVAC system is turned on or off, allowing air conditioning or heat to flow into the space depending on what the thermostat is programmed to read. Read this article for HVAC design considerations.

To have a smart gadget in your house, you could use an electrical engineer’s expertise to properly install a C-wire (common wire) to provide a return path to power the thermostat if you don’t have one already. This is done so that the thermostat can be powered without interrupting other electrical wires turning other equipment or devices on and off. Check out this blog post of ours that highlights electrical design considerations.

Positive and Negative Advantages of Smart Thermostats

Before deciding if a smart thermostat is the right choice for you and your home, you may want to make yourself familiar with some of the advantages and disadvantages to these devices.

A few positive benefits to owning one of these devices surround the user-interface and the sleekness of the device. The wireless aspect allows users to control temperatures from anywhere, receive notifications or alerts, and even sync with other smart devices in your home. Smart thermostats also may provide details on your HVAC system’s levels of energy use over time. This provides homeowners important information that may be necessary in the future.

Smart devices also provide the ability to learn the patterns in which you set your device, allowing the device to run as you like to heat and cool your home when it is occupied, or right before you come home. When the device learns your habits, it can reduce the amount of heating or cooling that is on when the space is empty for long periods of time.

Some of the negative aspects of smart thermostats can have a greater effect on power sources. While having one of these smart devices can make the user’s life easy because it learns their routine and determines how they like the temperature, it can cause power overloads to the electric power grid when too many users are on the same schedule. When and if these spikes happen, the electrical utility grid won’t be able to stop these spikes, resulting in using carbon producing fuel-powered generators to fulfill the electrical power overload.

“As we electrify the heating sector to decarbonize the grid,” said Max Zhang, a professor in Cornell’s Sibley School of Mechanical and Aerospace Engineering, “this so-called load synchronization will become a problem in the near future.”

Zhang concluded that smart thermostat owners are only saving 5-8% on their energy bills, yet the device claims you can save a potential 25-30%. Again, this is caused by most owners setting the thermostat on the factory settings which peak and fall at similar times of day as other smart thermostats in the same area.

One other potential disadvantage to smart thermostats is that they always require a wi-fi connection to to work effectively, and today’s wireless thermostats require more power than in the past. Without proper consistent wi-fi connection, there may be a connectivity issues between your thermostat controls and your heating/cooling equipment.

Potential Solutions to Scatter Energy Spikes

A few of Tec’s engineers weighed in offering potential solutions to aid the power grid overload so consumers can effectively and properly use these devices with better intended outcomes such as efficiency and less carbon fuel consumption. One potential method to scatter the spikes in electrical energy usage could be to stagger the timing of smart thermostats’, or other smart products’ power usage making them even smarter to help control stress on the grid.

Mike Ferrante, PE said, “If grid overload is a concern, perhaps considering spending more on grid infrastructure…to solve problems where power is provided to many, many residences in one area is a better way to address energy use spikes."

John Milenius, PE, and Director of Mechanical engineering suggests, “If you work from home, it is hard to realize the value from the (thermo)stat if there is no time for a setback temperature. A possible solution is for (manufacturers) of the thermostats to change the default settings to random times, so all the units don’t start at the same time. Since most people do not change the default settings on their SMART thermostat, that’s more probable and affordable than major upgrades to the entire grid.”

Prior to purchasing a smart thermostat for your home, one should consider the quality of Wi-Fi connectivity for your device to run smoothly. There are obviously some functionality benefits in owning a smart thermostat, but when it comes to many people owning them and operating them on similar default settings, it can cause some major issues for our electricity providers and could increase the concerns of brownouts and blackouts in your area.

If you have a smart thermostat or a suggestion on how to combat overloading the energy grid, we would love to hear your opinion on this topic as more homeowners investigate buying smart devices for their homes.


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