Sleeping With the HVAC

Insomnia? It may be the fault of your thermostat set point. It may be something more.                                                                                            

Comfort levels for sleep vary from person to person. And, one person’s perfect sleep temperature may be too high or too low for someone else. What we do know is that if one doesn’t get good sleep, the next day is going to be a difficult one!

A typical recommendation for the temperature for good sleep by medical professionals is between 65 and 75 degrees Fahrenheit. “Typically, a cooler temperature in the bedroom lends itself to better sleep,” says Chris Winter, MD, president of Charlottesville Neurology and Sleep Medicine in Virginia, when interviewed by Health magazine. He thinks 65 degrees is optimal. “A cooler environment usually lends itself to a better quality of sleep,” Dr. Winter tells Health

However, this contradicts Energy Star’s recommendation. Just last week, a social post citing the DOE’s suggestions for thermostat settings went viral saying that the thermostat should be set at 82 degrees in summertime when sleeping (78 while at home and 85 when you are away). With no medical finding behind their recommendation, the Department of Energy and the Environmental Protection Agency suggests this so that consumers can save money on cooling bills, but not just that, those set points will also improve indoor air quality and protect the environment.

So, we still ask the question: What is the best temperature set point for a good night’s sleep?

Ken Summers, vice-president of the Comfort Institute, says that the sweet spot for great sleep is not about the temperature set point of a thermostat; it’s more about humidity. In fact, he says “lower the temperature for sleep and you will raise the relative humidity…and that decreases comfort.”

Summers stated, “ASHRAE says a 75-degree thermostat setting with 45-50% humidity is going to make most people comfortable at night.” He’s right. When you think about it, most of the time we are awakened due to the discomfort of sweating. “That is because the level of humidity has risen, not the room temperature,” says Summers. In addition, a level of about 45% humidity will help rid a home of dust mites and other contaminants.

Maintaining thermostat set points and humidity levels can sometimes be difficult. The reason may be poor load calculations that led to inadequate equipment installations. Bad duct work is another problem. One’s comfort and sleep can be greatly affected by bad HVAC design including an imbalance of airflow, noise and hot/cold spots in the home.  Let’s consider each these problems for disrupting one’s sleep:

Air Flow

Let’s use a two-story home as an example of the problems created by bad design for airflow. Because heat rises, the upstairs (where bedrooms are typically located) will be 8 to 10 degrees warmer than the downstairs. That’s because the thermostat controlling the whole house is on the first floor. Thermostats only control the temperature where they are located.

A solution for this is to install zoning. Zoning allows the home to have multiple thermostats and dampers that control the air supplied to each area or “zone” of a home. When a zone requires conditioned air, the thermostat communicates to a panel that tells the damper to open and send it to that zone, but doesn’t affect the rooms where is not calling for air.

Balancing

While zoning is a best solution for air balancing, air vents can also control air flow, direction and volume. Opposed blade registers provide individual, adjustable blades running vertically in the front and horizontally in the back to better direct air in a single space, providing more comfort.

Hot/Cold Spots

Zoning and balancing are greatly important to controlling the flow of air in the home, but neither will work without good duct work. Ductwork has to be sized right, positioned right, and installed right to provide the comfort promised. Houses where the ducts that have deteriorated or are cracked and leak have major issues of hot and cold spots in the home. Those spaces are not getting the air they are designed to receive.

Duct sealing is a best solution for duct leakage. Duct sealing can be done using mastic or duct tape, but a most effective way to seal ductwork is with Aeroseal. Aeroseal seals holes in the ductwork from the inside, with an adhesive sealant that is injected in the air ducts and travels throughout to seal any holes 5/8” or smaller.

Indoor Air Quality (IAQ)

Breathing in contaminants while asleep–like animal dander, pollen, and dust–can aggravate your allergies. And, changing body temperature due to varying humidity levels can dry out and irritate the sinuses. Both can greatly disrupt sleep.

IAQ solutions like air cleaners, high efficiency filters, and humidification/dehumidications systems are absolutely necessary upgrades to better control comfort levels that promote great rest.

Noise

Finally, aging HVAC systems can create noise that would prevent anyone from falling (and staying) asleep. It is usually time to upgrade if the noise doesn’t quickly go away when the system kicks on. Noise can also be due to loose or deteriorating air ducts. So, have those inspected and corrected at the time of a replacement.

Lack of sleep due to the HVAC is never about one thing…the temperature set point of the thermostat. It is usually a combination of problems. Optimal comfort that leads to the best sleep has to include a properly sized HVAC system (preferably zoned), adequate controls, high efficiency air filters, good duct design, and grilles and registers.

This blog was contributed to ACCA from Denise Fournier-Tudor, Jackson Systems. Denise is long-time woman of HVAC and is Southwest Business Development Manager for Jackson Systems. She also serves on the Board of Directors for Women in HVAC. https://www.acca.org/news/guest-blog/sleeping-with-hvac

Updated: September 17, 2019 — 3:41 pm

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