When it comes to setting the thermostat, it can be a tricky proposition. First, you have the needs of people living in the home and many people have different ideas about optimal indoor temperatures. Next, you want to keep your home warm, but you don’t want to break the bank at the same time. Of course, there are passive methods to save money on energy bills with improved insulation and sealing gaps where air can escape. But, many savings can be made when you set the thermostat and your first choice is between the “On” and”Auto” settings. In this article, we will look at both settings in detail to help you make the right choice for your home.
Is This Setting That Important?
The short answer is yes, choosing between the “On” and “Auto” setting will dramatically affect the normal operation of your furnace. But, there is no right and wrong answer, but the setting you finally choose to use will be dependent on your own preferences. That being said, we do favor one over the other because it has greater energy efficiency benefits with no loss of performance. The “On” and “Auto” setting control the behaviour of the furnace fan (blower) that pushes the treated air throughout your home.
Understanding the “On” Thermostat Setting
It’s fair to say that the “On” thermostat setting is the default in most homes. But, this may be attributed to the fact that most people don’t know what the “Auto” setting does or they’ve never changed it. Essentially, when you have the “On” setting engaged the heating system will run the furnace fan constantly. There are a few pros and cons when you run the furnace fan constantly, they are:
The “On” Setting Pros
- When the thermostat is set to “On”, it will continuously cycle the air throughout your home and that includes the air filters. The indoor air quality (IAQ) is improved and people with allergies or breathing conditions may breathe easier. This benefit is further enhanced if you have electronic or UV air purifiers installed in your ducts.
- When the air cycles frequently, it collects airborne particulates including dust and moves them into the air filter. So, you may notice that you don’t need to dust your home as often.
- The indoor temperatures tend to be more even in a home where the furnace is running 24/7.
The “On” Setting Cons
- The furnace fan consumes energy, and if you run with this setting, you will see your energy bills rise.
- All those extra collected airborne particles will clog the air filter quickly and you will need to change the filter more often.
- If the furnace is not running, the furnace fan will begin to distribute cold air instead which will make the home uncomfortable in Winter.
Understanding the “Auto” Thermostat Setting
When you choose the “Auto” setting, the furnace will only run when it’s told to by your thermostat. In this way, the temperatures in the home can be maintained without running the furnace fan continuously. When you choose this option, there are a few pros and cons to consider, they are:
The “Auto” Setting Pros
- The main advantage of the “Auto” setting is that the furnace fan will not run 24/7 and that will lower your energy bills.
- The air filters won’t need to be changed or cleaned as frequently.
- When the fan runs constantly, it is more likely to fail and there may be frequent repairs.
The The “Auto” Setting Cons
- The slight improvement in your IAQ will be lowered.
- There may be more dust in your home and cleaning may be more frequent.
- When the furnace fan turns on and off again it can lead to wear and tear.
Which is Better?
Many heating experts consider the “Auto” setting to be better for most homes. The energy savings offset most of the disadvantages which can be dealt with in different ways. Let’s take a look at these issues in more detail.
Dealing with Extra Wear and Tear
If you have a modern high-efficiency furnace, it should last 15-18 years and that will give you a decent return on your initial investment. Even a more modest furnace can give you up to 12 years of dedicated service if you take care of it. To ensure that your furnace lasts towards the upper end of that projected lifespan, it’s a good idea to invest in regular maintenance. This will improve performance, efficiency and lower the cost of ownership. An annual inspection and tune-up before each heating season can help you to get the best performance and energy efficiency from your heating system. Regularly maintained equipment tends to run better and this will compensate for running with the “Auto” setting.
The IAQ Improvements
Although frequently cycling air does improve the IAQ slightly, there are more effective and efficient ways to deal with this problem. Upgrading your air filter is an obvious first step, but a filter with a higher MERV rating requires more force to push the air through. Air filters with high MERV ratings are extremely dense and they can overwork the equipment and drive up energy bills. A better alternative is an electronic air purifier or UV lights in the ductwork to sanitize the air. These methods will improve the IAQ to a degree that is far more effective for allergy sufferers and people with pre-existing breathing conditions.
Using the “On” setting does have significant advantages, but it will drive up your energy bills and the total cost of ownership may be higher. If you examine the alternatives to deal with these problems using other methods, they are more effective and less expensive. Adding a variable speed fan to your furnace is another great upgrade because the fan speed can be tailored to your current demands for heat. This is a more responsive option that also uses less energy. If you want to learn more about IAQ improvements and energy efficiency improvements, contact your local HVAC specialist today.