This year has gone by extraordinarily fast so far; it’s already May for crying out loud! Folks are getting their central and ductless air conditioners serviced and turning on their air conditioners for the first time. We want to clear some confusion on what a thermostat is, how to set your thermostat and when to consider upgrading your thermostat. We will also take a deep dive onto air filters. How does an air filter affect your heating and cooling system? What kind of air filter should I get? How often should I change my air filter?
What Really Is A Thermostat And How Do I Set It?
We get asked these questions a lot, “What temperature should I set my thermostat to?”, What is the fan button and, what should I do with that?
Let’s clear the air and take a deep, yet simple dive into your thermostat, how it works, and guide you in how to set it for YOUR comfort.
Firstly, your thermostat is nothing more than a glorified switch. Yes, that’s right, a switch, kind of like the one on your wall for lighting. It’s a bit more complicated than that but in general, it switches 24 volts of electricity across several, small wires back to your equipment to turn on your heat, air conditioning, fan, or whatever you may have.
As you can see in the picture above, this thermostat (my thermostat) is set for 68 degrees, in the summer I set it to 72 degrees. I set it to that because that is where I am most comfortable. That’s the key word there, “comfortable”. This is relative or course, some people may feel more comfortable at a higher or lower temperature, or lower. Others may set their thermostat to maximize their efficiency and opt to be a little warm in the summer and wear a sweater in the winter. The choice is yours on what you choose to do. We can only make recommendations based on what we typically see at other homes (between 68 and 72 degrees).
What about the fan?
Now here’s the fun part, the fan. At AirHeads HVAC, we recommend setting the fan in the summer to Auto mode. There are a few contractors out there that will recommend you leave the fan on “On”, or running 24/7. Their reasoning, to extend the life of the motor. We don’t concur with this statement, at least not fully.
How does it work?
The fan motor in your HVAC system will exist in one of two camps: a PSC (permanent split capacitor) or ECM (electronically commutated motor). All manufacturers are leaning towards ECM motors for their energy efficiency. Regardless, all motors draw something called starting current when starting. This is a short burst of electricity to push the motor up to speed. This starting current can be more stressful on PSC motors than ECM motors. PSC motors rely on the power stored in the capacitor to start, while the ECM “ramps up”, resulting in less abuse. Meanwhile, all motors have bearings. Bearings allow the motor to turn smoothly without much friction (rubbing). Consequently, the most common motor failure we see in the field is… you guessed it, bearing failure!
As long as the starting phase of the motor is kept short, and you have proper airflow, your fan should not experience excessive wear and tear due to starting at regular intervals. With regular, seasonal maintenance, we can monitor an adjust these is necessary.
The real problem (and the solution)!
Another key point is, when your central air conditioning system runs, it acts like a dehumidifier. Your indoor air conditioning coil, the part that cools your air, accumulates moisture from the humidity in your home. While most of it drains down and out of the house, some of it still latches to your coil. If your fan runs long after the AC cuts off, you’re moving the warm(er) air from your house through the coil. As a result, you’re absorbing moisture from the coil, and putting it back into your house. This seems counterproductive, doesn’t it?
We have heard this many times, “After my air conditioner turns off, it still feels sticky. What’s the problem?”. More often than not, their fan is on “On”. After recommending a solution and setting the fan properly, it is shocking how much this changes their comfort level.
On a lighter note, a fan operating 24/7 is going to consume electricity. While this is relatively small when operating automatically, it can raise your power consumption by a fair amount if left on.
It’s Not All Bad
To be fair, there is a silver-lining. The benefit to having the fan on all the time is having more even distribution of air in the home. Additionally, the air will constantly be filtered. In essence, if you’re sensitive to certain airborne contaminants, it may be beneficial to have the fan on all the time.
I heat mode, however, it doesn’t really matter. While we still recommend the fan to be in “Auto” mode, you won’t have the humidity issues that are prevalent in the summer. Nevertheless, thermostat manufacturers have been including, arguably one of the best features we have seen in years. This feature is called circulate, or “Circ”. The way it works is, during an off-cycle the thermostat will operate the fan for a few minutes every 15-20 minutes. This promotes the benefits of fan “On” (air mixing and filtering) while still maintaining good energy efficiency. We highly recommended this in the winter, or cooler months.
There are many offerings from highly reputable thermostat manufacturers, such as Honeywell and EcoBee, that offer this feature with great reliability, efficiency, and functionality.
If you have any questions on how to operate your thermostat, or would like to upgrade, feel free to call or text us at (484) 545-8015.
Air Filters, How Much is Too Much?
We’ve all been there; perusing the isles at The Home Depot, deciding what filter to buy. The size may be obvious, but what about the efficiency. Stores make it easy with something called MERV ratings and nifty diagrams. You are not at fault for wanting the best for you and your family. Nor are you at fault for wanting a filter that can not only trap mold spores, but ghosts as well!
Here’s the thing, can your heating and air conditioning system handle that super-powered air filter? Most of the time, no, it can’t. Let me explain.
Let’s Talk About Pressure!
Your heating and cooling system and its ductwork operates like your blood stream. Much like your blood stream it has pressure. For your heart, this is called blood pressure. Any doctor will tell you that an ideal blood pressure is about 120/80. Correspondingly, your heating and cooling system operates in the same way. We call it static pressure. If its too low, you have weak airflow, no air mixing, and poor circulation. Conversely, if it’s too high (high blood pressure), the system will be noisy, and the fan (heart) will be stressed, and it won’t last as long. It is important to balance the return and supply pressures to ensure a long life for the system. In conclusion, having a filter that is too powerful can weaken the airflow, drive up duct pressures, and in extreme cases, damage equipment.
However, this does not mean purchase the cheapest and weakest filter available. Otherwise known as mesh filters. This is a bit of a misnomer because, they essentially don’t filter much at all. If you’re unsure, generally it is best to go with a basic MERV 7 or 8 (cheapest) white pleated filter. This will help ensure you’re filtering out airborne contaminants, while not wearing out your equipment.
If you are unsure of what filter to get, we will be more than happy to assist you in the selection process. If needed, we can also recommend upgrading your filter to a thicker filter than can filter more and last longer. Thicker filters that are MERV 11 and above don’t have the same drag as their standard counterparts, while filtering out smaller contaminants. Furthermore, with their increased surface area they can last up to a year!
How Often Should I Change My Filter?
This is a loaded question. The easy answer is, it depends. If buying four filters a year and changing them seasonally is comforting for you and the old filter is not dark in color (or black), that is perfectly fine. However, if you’re unsure, start off by checking it once a month. We recommend changing the filter if the filter turns light grey. An easy way to test it is to hold it up to a light source and compare it to a new filter. If you see a nominal drop in light getting through, changes are air is having a hard time too. In the future, use this same interval, whether it be one month or six. It entirely depends on how much you use your system, or if you leave your fan on (more on that above).
Feel free to contact us (call or text) at (484) 545-8015 and we would be happy to answer any questions regarding filtering.
