You can tell if your furnace filter needs changing by visually inspecting it for a thick layer of dust, or if you notice your home feels stuffy, experiences weak airflow, or has a steady increase in dust. A general rule of thumb is to inspect the filter monthly and change it when it is visibly gray, clogged, or matted.
You can tell if your furnace filter needs changing by checking for visible dirt and dust buildup on the filter. Reduced airflow, increased dust in your home, or unusual furnace noises can also indicate a clogged filter.
A dirty filter is a breeding ground for bacteria, and too much build-up will cause the filter to break down and let some gunk through. Your AC will then circulate the dirty air through your home, which can lead to a sore throat from air conditioning. That's why most modern window ACs include a “Check Filter” light.
The $5,000 rule is a guideline to help homeowners decide whether to repair or replace their HVAC system. You multiply the age of your unit by the cost of the needed repair. If that number exceeds $5,000, replacing your HVAC system is often more cost-effective.
No, standard air filters and purifiers do not actively remove moisture from the air. Their purpose is to trap pollutants, not water molecules.
Yes. Humidity at 70% or above can make your bedroom feel sticky and uncomfortable, interfere with REM sleep, and increase wakefulness. High moisture levels also encourage mould, mildew, and dust mites, which can worsen allergies and respiratory issues, particularly during cooler months when ventilation may be limited.
5 Warning Signs It's Time for Furnace Replacement
The heat exchanger is often considered the most costly part of a furnace to repair or replace. It is a critical component that transfers heat from the combustion process to the air that circulates throughout your home. Over time, heat exchangers can crack due to the constant heating and cooling cycles they undergo.
The "two-foot rule" in HVAC is a duct design and installation guideline that requires a minimum of 24 inches of straight, uninterrupted space between branch take-offs (where air taps off the main trunk). It is also applied to spacing branches away from end caps, transitions, and the main plenum.
Respiratory Issues and Allergies
As your system struggles to push air through clogged filters, it redistributes pollutants throughout your home. This can irritate airways, leading to respiratory issues, worsening asthma symptoms, and triggering allergic reactions.
A sore throat at home is most commonly caused by dry indoor air, indoor allergies (like dust mites or pet dander), mold, or postnasal drip. It can also be a sign of a spreading viral illness (like a cold) or acid reflux acting up while lying down.
The 3-minute rule is a simple but important guideline: wait at least three minutes after turning your air conditioner off before turning it back on. That short pause gives the refrigerant pressure in the system time to equalize.
Failing to change your furnace filter restricts airflow, forcing the system to work harder. This strain spikes energy bills, degrades indoor air quality, and can cause the furnace to overheat, potentially leading to costly HVAC damage, system breakdowns, or expensive repairs.
A dirty furnace filter looks dark gray, brown, or black, often with a visible, thick buildup of dust, hair, and debris clogging the pleats. It will appear opaque, allowing little to no light to pass through if held up to a light source, and may feel rigid or matted with dirt.
5 Symptoms Of A Clogged Air Filter To Watch Out For
Simply put, it means you should never set your thermostat for a temperature more than 20 degrees cooler than the outside air. Why not? Most air conditioning systems can only handle a 20-degree difference between the outside and inside air temperatures.
The longest-lasting HVAC brands typically achieve a lifespan of 151515 to 202020 years (or even 202020 to 252525 years for ductless systems). Industry consensus points to Trane, Carrier, American Standard, and Mitsubishi as the most durable and reliable options.
The Rule of 5000 Rule is simple: Multiply the cost of the needed repair by the age of your air conditioner. If the result is greater than 5000, AC replacement is generally the smarter choice. If it's less than 5000, a repair might still be worth the investment. Here's a quick example.
What fails first on a furnace? The most common early failures are the furnace ignitor or flame sensor, as they experience regular wear and tear and are critical to starting the heating cycle.
A standard residential furnace lasts 15 to 20 years. However, the exact lifespan varies based on the type of system and how well it is maintained.
Most furnace issues stem from a few common culprits. The easiest to check yourself are clogged air filters and thermostat errors, which usually cause the system to blow cold air, run inefficiently, or cycle on and off constantly. Other frequent problems include dirty flame sensors or failing blower motors.
Scraping Sounds
Ask an expert, “What does a failing furnace sound like?” and they'll tell you to pay attention to any scraping or grinding noises. This distinct sound might indicate loose parts or issues with your blower motor.
You should probably Replace if: [ ] The repair costs more than 50% of a new unit. [ ] The furnace is over 15 years old. [ ] You have had to repair it more than once in the last 2 years.
To diagnose a furnace issue, start by checking the thermostat settings and ensuring it's set to "heat" and at the right temperature. Inspect the air filter for clogs and replace if dirty. Ensure the furnace switch and circuit breaker are on.