The old heating standard of 66°F is no longer the go-to temperature for modern homes. An HVAC expert reveals the optimal, eco-friendly setting that will keep your home cozy and healthy.
For years, the advice has been to maintain a steady 66°F (19°C) indoors. However, this recommendation is outdated and doesn't consider the advancements in home construction and our daily habits.
Our HVAC pro suggests a slight adjustment to 68-70°F (20-21°C) during winter. This simple tweak ensures your home stays warm, your energy bills remain manageable, and your health and home structures are protected.
The Dangers of Underheating
Josh Mitchell, an HVAC technician and founder of Air Conditioner Lab, explains the hidden risks of keeping your home too cool. When indoor temperatures hover around 66°F, wall and ceiling surfaces can drop below 60°F (16°C), especially in homes with poor airflow or cold exterior walls.
This creates the perfect environment for mold to thrive. Josh has witnessed mold growth behind wardrobes, in basements, and even in upstairs corners where insulation was compressed.
"In one case, the interior drywall measured 58°F (14.5°C) with 58% humidity. That's all it takes for mold to start forming," Josh says.
Experts now warn homeowners to avoid these silent, hidden risks by raising the thermostat slightly to the new safe heating zone.
The Benefits of Warmer Temperatures
By bumping the thermostat to 68-70°F, you can keep interior surfaces warmer and drier, reducing the chances of mold and minimizing thermal stress on walls.
Additionally, your HVAC system will run more efficiently. At 70°F, your return air stays warm enough to prevent short cycles, especially on multi-stage furnaces and variable-speed air handlers.
"Short cycling can lead to rusting and flue gas condensation over time, potentially damaging your HVAC system and resulting in costly repairs," Josh adds.
Not only does a warmer home protect your HVAC system, but it also supports your health. Low indoor temperatures slow the function of the cilia in your nose and lungs, reducing your body's ability to filter out viruses and bacteria.
Studies in Europe have found that homes under 64°F pose increased health risks, with a threefold increase in respiratory illnesses during winter, especially for vulnerable age groups like babies and the elderly.
Exceptions and Considerations
There are exceptions to the rule, as Josh points out. Homes with closed-cell spray foam insulation and triple-pane low-E windows can maintain a stable 66°F with fewer issues.
However, if your home has R-11 fiberglass batts, older single-pane windows, or a vented crawl space, Josh recommends never going below 70°F in winter.
While keeping a cooler home may save on heating costs, the potential risks and costs associated with mold, health issues, and HVAC damage can outweigh these savings.
Checking Your Home's Health
To monitor your home's humidity and surface temperatures, invest in a basic IR thermometer and a digital hygrometer. These affordable tools are available on Amazon and can help you identify potential issues.
Josh advises that if your walls are below 60°F and the humidity is above 55%, your home is at risk of dampness, mold, and health hazards. In such cases, you'll need to raise the temperature, reduce humidity, improve ventilation, or use a good dehumidifier.
Shop Smart for a Cozy Home
Here are some products to help you create a warm and healthy home environment:
- Thermopro TP30 Infrared Thermometer Gun: Instantly measure surface temperatures to identify potential mold risks.
- Baldrtherm Room Thermometer & Indoor Humidity Meter: Keep track of your indoor temperature and humidity levels, aiming for the optimal 30-50% range to avoid mold and respiratory issues.
- Deepsoon Heating Pad: Zone heating with this auto-shutoff pad reduces energy costs and winter aches.
- Woolrich Alton Comforter Set: Ottilie Blackhall, our sleep testing expert, recommends this cozy, hypoallergenic comforter set for a good night's sleep without cranking up the heat.
- Givebest Space Heater: A small, portable heater with safety features can provide extra warmth without breaking the bank.
- Frigidaire Gallery Dehumidifier: Reduce indoor humidity and create a healthier environment with this Wi-Fi-connected dehumidifier.
Remember, if your HVAC system is sized for a 70°F target temperature, dropping it to 66°F can lead to longer runtimes and uncomfortable hot and cold spots in your home.
So, are you ready to make the switch to a warmer, healthier home? We'd love to hear your thoughts and experiences in the comments below!
