Considering how smart the smart thermostats are, you might expect that they could set the temperature themselves.
While they do pick out sane defaults, this isn’t the same thing as giving them good solid input and then allowing them to learn good temperatures based on this input.
There used to be a principle in computer science that was summed down with the phrase “garbage in, garbage out.”
If you give your smart thermostat the right temperature to work with, then it can work wonders and potentially save a good deal of energy.
Giving it flawed settings to start with could hamper how much power it saves, so take a few moments to learn a bit more about how to set an ideal temperature.
Factors to Consider When Setting Temperature
Daily Schedule
Setting your home’s temperature around your daily schedule is one field that smart thermostats really excel at, but they still need to know what your daily schedule is. Systems that use room sensors like the ecobee4 or electronic eyes like the Nest series will be able to pick up on when you’re in the house.
Other devices like the Honeywell RTH9580WF may present you with a calendar that you’ll want to fill in so your thermostat knows when you’re not around. In either case, they’ll pick up on your schedule very quickly.
Once they do, they’ll begin throttling back the temperature each time you’re not home and then bring it back to more comfortable levels when you return. Think about how far out of your comfort range you wouldn’t mind having your home when you’re not there.
It might seem foolish to set your thermostat to something rather cold in the winter, but keep in mind that you’ll be moving around when you first get in the door so you’ll feel nice and warm anyway. In the summer, setting it fairly high won’t be an issue because it will still be rather cool compared to outdoor temperatures. Your HVAC system will compensate for the change without too much difficulty anyway. This type of compensation won’t put unnecessary strain on it either.
Climate Zone
Recommended thermostat settings will always be different depending on the climate you’re living in. A good rule of thumb would be to set your home’s cooling system around 78-80° Fahrenheit while you’re home and up to 10° warmer when you’re not. Some HVAC experts estimate that each degree higher you set your thermostat over 78 in the summer translates into upwards of an eight percent off your energy bill. Your mileage may vary, but this is certainly a big incentive.
These savings aren’t even calculated on a daily basis. Officials from the US Department of Energy estimated that homeowners who shifted their thermostats approximately 7-10° for eight hours a day while leaving it at their previous setting for the other 16 hours of the day for a whole year cut their energy uses by as much as 10 percent annually. They also found that the percentage of savings from this setback is greatest in mild climates. Since most people live in relatively mild conditions, this is great news.
Winter savings aren’t as dramatic because furnaces are more efficient, but you should be able to save around five percent on your bill if you set your thermostat lower by around 12° when you’re not home. Many people feel that 68° is a decent daytime home temperature during the winter. In spite of the efficiency differences, you might still be able to save even more energy during the winter if you’ve been running your thermostat much too high without realizing it.
Weather Conditions
Weather doesn’t matter as much as you might think because comfort levels are subjective, but smart thermostats usually automatically adjust to weather conditions. If you see that things are going to be cooler, though, then don’t be afraid to dial down your AC from a compatible mobile app. When the Honeywell RTH9580WF came out, the at-a-glance weather forecasts had an unexpected effect in that they encouraged people to turn their AC off and open the windows on nice days. They also helped homeowners set the temperature during unpredictable spring days.
Your Activity Level
Activity level can influence the internal temperature as well. If you made sure to program a decent schedule, then this shouldn’t matter too much. The more active you are in your home, the more warmth you’ll feel. If you’re always using the oven during the winter months, then your furnace won’t switch on as much. What you might want to compensate for is personal internal movement, which won’t be enough to influence your HVAC system by itself.
For instance, if you relax on lazy summer days you won’t feel as hot so you can dial the AC down. If you’re moving around opening presents with guests during the winter, then you can turn back your furnace a few degrees without noticing. You can program a schedule that takes advantage of these sorts of events beforehand.
How Smart Thermostats Keep Right Temperature
What Is The Smart Thermostat?
Any thermostat that uses computer technology is technically smart insofar as engineers use that term. When people use the phrase smart thermostat, they usually mean units that connect via WiFi and communicate with a network. These networking tricks help to keep a solid temperature.
Smart Thermostat Features
Networking your smart thermostat with a mobile device will immediately let it know when you’re not in the house. For instance, Nest products use a trademarked technology called Home/Away Assist that tracks the location of your smartphone and immediately adjusts the temperature accordingly.
You’ll save energy each time you leave, though you’ll want to make sure that you keep in mind that if you lend your phone out your thermostat might wrongfully think you’re out of the house. Room sensors and electronic eyes also tell your thermostat when you’re somewhere else. They can also learn other aspects of your schedule, which is helpful because people usually have different temperature tolerances while they’re sleeping.
Programming functions offer the potential to save thousands of kilowatt-hours annually. Energy Star representatives once claimed that homeowners can save 10 percent a year on their heating and cooling bills by setting a schedule. These schedules come in several different flavors.
Weekly models offer the greatest flexibility since they let homeowners set different programs for different periods on each day of the week. You’ll sometimes see smart thermostats that promote 5+2 models, which have Monday through Friday schedules ordered separately from weekends. There are also 5-1-1 models, which feature two different weekend settings along with a weekday setting.
How to Use Smart Thermostat in a Smart Way?
A few basic programming tips will work with any of these models. Shut down your heat or AC unit about a half hour before you leave home. Turn it back on approximately a half hour before you return, and then shut it off around an hour before you go to sleep. Don’t increase your furnace or AC unit again until around a half hour before you get up. You’ll probably need to tweak the program for a few weeks, but something like this should work if your smart thermostat doesn’t have room sensors or another way to tell if you’re there.
Smart thermostats save the most energy when their setback temperature is put at an ideal setting. You may want to dial your thermostat back a huge amount, but don’t be surprised if it advises you to jump back only two or three degrees to start with. It doesn’t want to make your HVAC system work itself to death.
Configuring Smart Thermostat
Now that you know you need your thermostat locked in at an ideal setting, you’ll want to figure out what the ideal position is for your location. This generally differs based on the season. If you remember what you had your old thermostat set to, then try these settings to start with. Depending on which brand of thermostat you have, you’ll possibly get a message about whether or not these settings make sense.
Recommended Temperature for Summer (78°F/26°C)
The US Department of Energy has long recommended 78°F/26°C for the summer months as an ideal starting point. This is warm enough to avoid wasting electricity but still cool enough to keep most people comfortable.
If you choose a setback temperature around 87-89°F/31-32°C, then you can program your thermostat to cool your house back down shortly before you come home each day. You’d never know that the AC unit was shut off for most of the day by using this method.
Recommended Temperature for Winter (68°F/20C°)
Unlike summer, you can’t be this liberal when choosing a setback position in the winter months if your area regularly freezes. Don’t allow your home to drop below 55°F/13°C or so to prevent frozen pipes from becoming an issue.
The recommended temperature for winter is 68°F/20°C. You can set to this temperature while you are awake and drop when you sleep. Most of the smart thermostats will also allow you to manage temperature while you are away from home.
Most people like to keep their homes warm, but you should still think about the climate your house might like if you leave it for long periods of time during the winter. While a sunny climate in another state might be your home during these months, your Northern home still has to put up with less than ideal conditions.
Tips for Setting the Right Temperature
Flowcharts exist that can help you pick the right settings for a perfect home climate, but all you really need are a few basic rules of thumb. Never try to cool your home faster by putting your thermostat down at a ridiculous setting then raising it to a sane one. This strategy doesn’t work and it can seriously run your bill up.
You can, however, dress down in the summer and wear more clothing in the winter. This should allow you to alter your temperature settings by as much as four or five degrees either way. Unfortunately, your smart thermostat has no way of knowing how you’re dressed, so you’ll have to adjust the schedule if you adopt this strategy.
Like some Honeywell RTH9580WF owners have learned, nothing beats the genuine fresh air. Natural conditions might make the best climate for you, so don’t be afraid to ventilate your house the old-fashioned way. Smart thermostat displays can even tell you when the best time to open everything up is if you haven’t done so in a while. Don’t forget that you could also turn your air conditioner completely off whenever you’re not home, though this isn’t always practical depending on your climate.
Temperature for Maximum Energy Savings
If you’re trying to save the most energy you possibly can even after configuring your thermostat for a perfect interior climate, then you’ll want to familiarize yourself with what all of the various options on your thermostat do. Most of these are explained in the manual, but you might get tripped up by the fact that there are two automatic settings on most thermostat interfaces.
One of these two settings is for the whole house fan. In most cases, you’ll want to leave this on automatic, though with some thermostats like the Honeywell RTH9580WF you can run it independent of your HVAC system. A fan uses less electricity than an AC unit by several orders of magnitude, so this is a nice way to reduce current draw when your house needs ventilation. When left on automatic, your HVAC system will decide when to turn it on in order to circulate hot or cool air through your vents.
The second automatic setting involves the schedule that you set on your smart thermostat. It allows your thermostat to put your plan into action. Before you turn this option on, make sure that your plan is every bit as smart as your thermostat. Make sure you’ve made a few simple changes too.
Turn off any unnecessary lights and close curtains to block out heat in the summer months. If you have ceiling fans, then turn these on to circulate the air. They can help you tolerate internal temperatures several degrees higher and you can alter your schedule accordingly. Ceiling fans use a good deal less electricity than an AC unit does. You can also use box or table fans, though these might use slightly more energy. The extra airflow will blow heat away from you, which means less work for your more energy-hungry HVAC system to do.
Blankets always work in the winter, and many people find them more comfortable than bumping up the thermostat each time it gets a little cooler. Heaters make your home feel more dry, which is a major comfort issue. You won’t have this if you drop the thermostat a bit whenever you snuggle up under a comforter. Valentine’s Day is in the winter, so you might even have someone to snuggle up with!
Programming your thermostat for eight-hour intervals is usually the most efficient method. You can divide a 24 hour day into three different shifts this way. Anything shorter is a waste.
Some smart thermostats require a battery to continue functioning properly. Make sure that you change the battery if necessary. Under volt, conditions can cause thermostats to do some screwy things that might end up switching your HVAC system on and off unnecessarily.
Manufacturers usually provide recommended adjustment patterns. To follow these, start with the highest comfortable setting in the summer or the lowest in the winter and then turn it up or down accordingly. One expert recommended 10° shifts in the day but more comfortable 4° shifts at night. Taking a few moments to learn a bit more about the specific features of the model of thermostat that you have will go a long way toward meeting these patterns.
Other Money saving tips
Your ducts can’t increase airflow if they’re clogged. Cleaning them out is an excellent way to make your HVAC system work better, and there are many professional services that will take care of this if you don’t feel comfortable doing it yourself. On the other hand, this is an excellent weekend project that will save money and might even provide some relief for allergy sufferers.
A simple canister vacuum is all you’ll need. You can start by removing the registers and carefully feeding a vacuum hose down them. If your system isn’t too dirty, then this will probably pull out more than enough soil to make any further action unnecessary. There are more thorough methods to try if the system is really dirty. You could even disassemble the ductwork yourself if you feel comfortable, but you might want to get in touch with a professional if you don’t feel confident about this kind of work.
Changing your furnace filter is an excellent idea as well. Furnace filters come in varieties that last for several months, so you’ll want to invest in one that will hold up for a while if you’re replacing an old one yourself. You can write the date on the new one to remind you of when you need to change it next. Cleaning your AC condenser and sealing up ducts while your at it will keep your system running smooth. This should help to reduce the amount of work your HVAC system has to do while heating or cooling your house as well, which in turn saves power.
Some home automation systems can also take control of hot water heaters, but if you’re using a smart thermostat that only controls the HVAC system then you’ll need to take care of this yourself. To reduce energy usage, you’ll probably want to set your tank temperature to around 120° or so. Those who live in manufactured homes might be able to turn the tank on and off completely with a switch.
Resources & Further Reading
Temperature Setting
Programming Your Thermostat This Spring
Choose the Right Programmable Thermostat
Smart Thermostats
Maximize Energy Savings with Your Nest Learning Thermostat
Programmable Thermostat Savings
Set Programmable Thermostat Right For Every Season
5 Tips About Programmable Thermostats
Home Climate
Recommended Thermostat Settings for Summer
Recommended Thermostat Settings Flowchart
Maximizing Savings
Heating and Cooling Guide (PDF)
Managing Your Thermostat Control
What Temperature Should my Thermostat be Set At?
More Money-Saving Tips
How To Clean Ventilation Ducts
How To Replace Furnace Filters
