Heat Pumps
Heatwave in Chapel Hill: My HVAC Unit Is Gasping in This Heat
By Jonathan Poston•June 22, 2025
It’s June 23, 2025, at 11:37 a.m. as I’m writing this article in Chapel Hill, NC. The thermostat shows 91°F, and we’re still hours from the day’s peak temperature. The National Weather Service has issued an Extreme Heat Warning, warning of triple-digit temperatures, heat indexes over 105-110°F, and no real relief in sight.
My 24-year-old HVAC unit is already showing signs of struggle as it gets hotter outside. It’s running longer cycles, pushing out less cold air, and making that low mechanical noise that sounds like a groan.
Weather forecasters and experts are saying this heat dome is going to settle over the South and Central U.S. through midweek. Here’s a quick snapshot of how things are shaping up in surrounding cities:
| City | Expected High Today (°F) |
|---|---|
| Chapel Hill, NC | 100 °F |
| Raleigh, NC | 100 °F |
| Durham, NC | 99-100 °F |
| Greensboro, NC | 100 °F |
| Charlotte, NC | 98-100 °F |
| Washington, DC | ~100 °F |
| Philadelphia, PA | ~100 °F |
| New York City, NY | 100 °F |
| Boston, MA | 95-100 °F |
| Chicago, IL | 95-100 °F |
| Nashville, TN | 100+ °F |
| Cleveland, OH | 100+ °F |
| Louisville, KY | 100+ °F |
| Minneapolis, MN | High 90s-100 °F |
Map of Heat Wave 2025
Tips for Surviving the Heat with an Old HVAC Unit
If your air conditioning system is older like mine, you’ll want to be proactive this week. Here’s what I’m doing – and what you should consider too:
Change Your Air Filter
Even if it doesn’t look dirty, replace it. A clogged filter restricts airflow and makes your system work overtime, which it absolutely doesn’t need in this heat.
Cool Your Home Early
I dropped my thermostat to 72°F early this morning. It’s easier (and cheaper) to maintain a cooler home early in the day than to cool it down from 85+°F in the middle of the afternoon.
Close Blinds and Curtains
Keep sunlight out to reduce heat gain. Your AC is already overworked; it doesn’t need to fight the sun too.
Check Vents for Blockages
Make sure furniture, rugs, or boxes aren’t blocking air supply or return vents. You need every bit of airflow working efficiently right now.
Avoid Heat-Producing Appliances
I’m skipping the oven and dryer today. Using them adds unnecessary heat to your home and makes your AC work harder.
Don’t Turn Your AC Off When You Leave
It might seem like a way to save energy, but if you shut the AC off completely, your system will work brutally hard to cool things back down when you return. It may even fail in the process.
Look for Signs of Failure
Are you noticing grinding noises, short cycling, or warm air? That’s your HVAC crying for help. If you hear it, call a tech early – before everyone else’s system fails, too.
Keep an Eye on Your Furry Friends
Pets are especially vulnerable to high heat, as they can’t regulate their body temperature as efficiently as humans. Dogs and cats, for example, are most comfortable in indoor temperatures between 68°F and 78°F.
When outdoor temperatures soar, it’s important to keep your HVAC system running to maintain a safe and comfortable environment for them. Ideally, set your thermostat to no higher than 78°F when you’re away and a bit cooler when you’re home.
Make sure pets have access to fresh water, avoid walks during peak heat hours, and never leave them in a hot room or garage without ventilation. Even small temperature increases can pose risks, especially for short-nosed breeds, elderly pets, and those with health conditions.
| Pet | Comfortable Temperature Range (°F) | Heat Risk Above (°F) | Notes |
|---|---|---|---|
| Dogs | 68-78 | 85+ | Brachycephalic (short-nosed) breeds like bulldogs and pugs are higher risk. |
| Cats | 70-80 | 90+ | Generally better at hiding discomfort; watch for signs of overheating. |
| Rabbits | 60-70 | 80+ | Very heat-sensitive; require cool environments and shade. |
| Birds | 65-80 | 85+ | Need good airflow and shaded perches; parrots may tolerate slightly warmer temps. |
| Hamsters | 65-75 | 80+ | Prone to heatstroke; keep in a cool, well-ventilated area. |
| Reptiles | Varies by species | Species-specific | Require temperature gradients; too much heat without escape is dangerous. |
| Guinea Pigs | 65-75 | 80+ | Cannot sweat or pant – very vulnerable to heatstroke. |
| Ferrets | 60-70 | 80+ | High risk of heat exhaustion; prefer cool environments. |
| Fish (Aquarium) | 72-78 (tropical), 60-70 (cold water) | 80+ (tropical), 75+ (cold water) | High temps reduce oxygen; use a tank thermometer. |
Stay Safe During a Heat Wave
This heat is no joke, and it’s just getting started. For those of us with older AC units, it’s a daily battle between climate control and climate collapse. For those in rural areas where there is no mall or cool location to go to in case the HVAC unit stops working, it's ideally worth looking at installing a new HVAC before the heat wave comes your way. We can help with that: The refreshingly different way to replace your HVAC
References:
https://people.com/heat-wave-sweeps-us-see-which-cities-affected-how-hot-could-get-11758483
https://www.climatecentral.org/climate-shift-index-alert/central-eastern-us-june-2025
https://www.washingtonpost.com/weather/2025/06/23/heat-wave-humidity-east-coast-forecast/