Indoor Air Quality
The Five Systems We Measure to Make the Air in Your Home Safer to Breathe.
Most homeowners think they have a temperature problem. What we typically find is a humidity problem, an airflow problem, or a filtration problem, wearing a temperature problem like a costume.
From Joel Verley · Owner, Triangle Trade Professionals · Raleigh, NC
Here's what we found
Most Raleigh homes we test in summer run between 55% and 65% indoor relative humidity, even with the AC running. The healthy range is 30–50%.
That's why we see the same pattern over and over: the thermostat keeps going down. 72. 71. 70. 69. The homeowner says, "I just can't get comfortable."
They think they're chasing temperature. They're not.
They're chasing humidity.
If your home held the textbook ideal of 73–74°F with proper humidity control, you'd be comfortable. The problem is, when humidity is high, no temperature feels right. So homeowners crank the thermostat down, using cooling to fight a moisture problem. Expensive. Incomplete. And it does nothing for indoor air quality.
Humidity is the secret comfort maker. It's also the largest driver of indoor air quality problems in the Triangle. Mold, mildew, dust mites, and the allergens that ride along with them all need moisture to thrive. If you've been fighting allergies inside your home, that's where to start looking.
Your HVAC system is the largest air-handling machine in your house. Tuned correctly, it does more than cool, it filters, dries, and refreshes the air your family breathes. Here are the five components we measure and tune to make that happen, and where each one fits with the maintenance plan you already have with us.
System № 01
High-Efficiency Filtration
Data
Most basic 1-inch filters capture particles 5 microns and larger. The allergens you're worried about, pollen fragments, mold spores, pet dander, dust-mite debris, are 0.3 to 10 microns. Most of them pass straight through.
What it means
Your factory filter is protecting your equipment, not your lungs. To stop allergens, you need a filter rated MERV 13 or higher, but only if your blower can handle the resistance without choking airflow.
Your options
We measure static pressure across your filter on every tune-up. If your system can run a MERV 13 safely, we'll tell you. If it would need a media cabinet retrofit to do it right, we'll show you the cost before anything happens. We don't guess, we measure.
System № 02
Coil-Mounted UV Light
Data
Your evaporator coil sits at around 50°F with constant condensation when the AC is running. That's the textbook environment for mold and biofilm growth.
What it means
Mold on the coil means mold spores in every room your blower serves. Filtration alone won't fix this, the spores are downstream of the filter.
Your options
A UV-C light installed at the coil kills the microorganisms before they multiply. Standard bulbs need replacement every 12 months, old bulbs still glow but lose most of their germicidal output. Two-year bulbs are also available if you'd rather extend the replacement interval. Bulb replacements are billed at the time of service. If we see signs of biological growth on your coil, we'll show you what we're seeing before recommending anything.
System № 03
Whole-Home Dehumidification
Data
Healthy indoor relative humidity is 30–50%. Most Raleigh homes we measure run 55–65% in summer. The AC removes some moisture as a byproduct of cooling, but it was never built to be your primary dehumidifier.
What it means
This is the humidity-as-temperature problem we opened with. Drop the thermostat low enough and you'll squeeze some moisture out, but you'll overcool the house, run up the bill, and still feel clammy. The variable you're chasing isn't on the thermostat.
Your options
A dedicated whole-home dehumidifier ducted to your return treats moisture removal as its own job. The result: thermostat at 73–74°F, humidity at 45%, and the house finally feels right. It's the upgrade many members tell us made the biggest day-to-day comfort difference of anything we've installed.
System № 04
Whole-Home Air Purifier
Data
The EPA reports indoor air typically carries 2 to 5 times more pollutants than outdoor air, and occasionally more than 100 times higher. VOCs from cleaners and finishes, microbial activity, and fine particulate that filtration alone doesn't address.
What it means
A high-MERV filter handles particles. It does not break down VOCs or kill microorganisms drifting through the duct system between filter changes.
Your options
An in-duct purifier combines high-MERV filtration, UV-C, and ionization in one unit. Earns its place in homes with severe allergies, asthma, multiple pets, or active remodeling. Doesn't earn its place in every home. If your situation calls for one, we'll say so. If it doesn't, we'll tell you that too.
System № 05
Energy Recovery Ventilator
Data
Newer Triangle homes, especially post-2010 builds with spray foam insulation, are tested at low air-change rates. CO₂, cooking byproducts, VOCs, and humidity have nowhere to go.
What it means
A tight envelope is good for the energy bill and bad for indoor air quality. The same construction that keeps your power costs down traps everything you exhale and everything your home off-gasses.
Your options
An ERV brings in fresh outdoor air on a controlled schedule and recovers most of the heat and humidity in the process, so you're not throwing your conditioned air out the window. Older drafty homes don't need one. They're already over-ventilated, often without realizing it.
One more thing
The Threat None of These Five Systems Catch
Filtration, UV, dehumidification, purification, and ventilation cover the indoor air you can feel, particles, humidity, microbial growth, stale CO₂. None of them touch radon: a naturally occurring radioactive gas that seeps up through foundations and crawl spaces across much of central North Carolina. The EPA calls it the second leading cause of lung cancer in the U.S. You can't see it, smell it, or taste it, and two houses on the same street can test wildly differently.
The only way to know your number is to measure it. We'll cover what to do about radon, and the monitor we keep in our own home, in the CTA below.
What we'll do at your next tune-up, included with your membership
At every membership tune-up, we'll:
- Measure your indoor humidity.
- Check static pressure.
- Inspect the coil for biological growth.
- Show you a report of our findings and readings.
- Explain what they mean and walk you through your options.
And if you've picked up the Airthings View Plus, we'll pull in that data too, so future maintenance visits get more action-oriented over time, based on what's actually happening in your home between visits.
If everything's in range, we'll tell you that and move on. If something's off, you'll see the data yourself and decide what to do about it.
No pressure, just clarity.
Ready to see your home's numbers?
Filtration, UV, dehumidification, purification, and ventilation cover the air you can feel. They don't cover radon, the one indoor air threat that's invisible, odorless, and statistically the second leading cause of lung cancer in the U.S. The monitor we use in our own home tracks radon continuously alongside six other things that matter. We've put together a TTP-exclusive 10% off code and the full breakdown.
See the monitor we recommend →If this were my home, here's what I'd do.
Joel Verley
Owner · Triangle Trade Professionals
