5 AC Fixes To Cool Down Your Too-Hot Home This Summer

With summer heatwaves picking up, it's harder than ever to keep your home cool, even if you do have central air conditioning. Pets, plants, kids and the elderly can all suffer if home temperatures get too hot, and extra fans can be an energy sink without always cooling effectively. 

What does make a difference is proper maintenance and controls for your HVAC system. If it's been a while since you changed your AC habits, you can make a huge difference with a little care. Here's what works best. 

First: A speedy primer on HVAC

Short for "heating, ventilation and air conditioning," HVAC units are true marvels of engineering. Commonly referred to as "central air," these machines are really multiple components, even separate appliances, that all work in concert. They also share a single ventilation network, the collection of metal vents that snake through modern homes.

In the winter, a furnace (powered by fuels like natural gas or propane) or a heat pump (like an air conditioner, but in reverse), helps keep rooms warm. In the dog days of summer, an air conditioner module kicks on to both cool the air and wick away excess humidity.  In both cases, a fan system works to spread air via vents to the rooms in your house and drawn it back into the system. 

Running the show is a remote, wall-mounted thermostat (and possibly a humidistat) that constantly samples indoor conditions and issues commands to the HVAC accordingly. With so many parts operating in tandem, both mechanical and electronic, if one component slips out of place, you'll be sweating in a hothouse in no time.

Enlarge Image

1. Install a smart thermostat

The easiest way to save money and make your HVAC unit more efficient is to upgrade to a smart thermostat. Devices like the Nest and Ecobee intelligently control your air conditioner's activity. One way they do this is by using motion sensors to sense your presence and adjust the AC run time accordingly. Smart thermostats even factor local weather into the equation.

By optimizing this activity, your HVAC unit is less taxed and more efficient. In fact, the US Department of Energy says an efficiently controlled thermostat could save you as much as 10% a year on heating and cooling costs. 

2. Change the air filter (and save money)

The simplest way to keep your HVAC happy is to change its air filter often. Clean filters save money and increase HVAC safety too. Most home HVAC systems use just one: a paper filter that sits between the primary return vent and the system's main intake. Designed to trap dirt, dust and other airborne particles, clean filters strain the air while ensuring a smooth flow. At minimum, you should swap in a fresh filter twice a year, at the start of spring and fall. 

Unchanged filters are often clogged with debris, slowing air flow to a trickle. This causes your home to cool slowly and your AC to run longer and harder than usual. The extra load strains internal HVAC components as well like blower fans and cooling (evaporator) coils. Ultimately, if pushed too hard for too long, these parts won't function properly or fail entirely.

One common summertime symptom often caused by poor air flow are frozen evaporator coils. Less air hitting your AC's coils, designed to pull heat from hot homes, means they become cold enough to condense environmental water vapor into solid ice. If you see signs like this, along with a struggling AC, it's time for a cleaning and new filter ASAP.

3. Manage your airflow carefully

Your path to a cooler house might be as easy as opening doors and registers (vents found either on the floor or ceiling) in every room. If designed and built correctly, a central air system should be "balanced." A balanced system is one where negative pressure, or airflow in one direction, should match positive air pressure pushing air in the opposite direction.

HVAC pros often achieve this state of freely circulating air with no blockages present like closed doors or shut room registers. As a homeowner, you have a choice: You can try to close off some unused rooms and concentrating the cool air in the rooms where people spend time, or you can open all vents and doors to let air flow as freely as possible. The best solution depends on the size and shape of your home, so a little experimenting will help you find which option cools most effectively. 

As you work, make sure you are keeping windows and doors closed in the heat. They will only let cool air escape and hot air enter during the day, doing more harm than good.

4. Check for closed dampers

Some homes have HVAC ductwork equipped with air dampers. These dampers (aka valves) are designed to control the flow of air through specific rooms or even entire floors. Unlike registers which are visible through grilles on the floor or ceiling, dampers are mostly hidden inside ductwork. Look for what you can see, handles or knobs on the exterior of ducts which you can rotate from the outside. They should allow you to articulate their valves open, closed or some degree in between. 

5. Call in the pros

When all else fails and your home's central air system can't keep its environment cool enough for comfort, asking for professional help is a shrewd move. An HVAC pro can tackle important jobs you can't or shouldn't attempt yourself. 

• Check your entire system top to bottom for leaks.
  
• Notice abnormally low air pressure or movement.
  
• Clean tough-to-reach components like your AC evaporator coils.
  
• Measure and analyze strange electricity usage.
  
• Replenish low refrigerant levels if necessary. 
  

You should also strongly consider signing up for a seasonal maintenance plan. A $100-$200 annual fee sounds like a good deal compared with the thousands that replacing the entire system would set you back.

Regardless, avoid any outfit pushing you to pay for duct cleaning or a similar service. The Environmental Protection Agency cautions that the health benefits of cleaning HVAC ducts remain unproven. Even the National Air Duct Cleaners Association, whose members handle rare instances of mold infestations or chemical contamination, warns against the glut of scammers operating falsely under its name. 

With your air conditioning ready to put in long hours, stop by our guides on how to keep your kitchen cool in a heatwave, tips on sleeping cool in the summer and general home tips on surviving high heat even when your AC is working like a champ.