Hot summer weather can have us running back and forth to the thermostat in an effort to find the “just right” setting for indoor comfort. In this article, Leith Heating & Cooling, your go-to team for professional AC repair in Elgin, IL, discusses the science involved in air conditioning and addresses the question, “What temp should air be coming out of AC vents?”
How Air Conditioners Work
To understand the importance of the temperature of air blowing from your air conditioning vents, we must first look at the basic function of all air conditioning systems. They do not “produce” cold air — rather, an air conditioning system works by removing heat and excess humidity from indoor air and then recycling it throughout your house.
Supply and Return Air
Supply air is the cooled air sent by your unit through the ductwork and the supply vents into the inside of your home. Return air is the air drawn from the inside of your home through a return vent back into the system to be cooled again.
The air filter that you regularly change fits over the return vent. The circulation effect creates a regular airflow that maintains your home at a comfortable temperature that you set on the thermostat.
As warm air enters the intake vent and cooled air circulates back through the supply vents, the important measurement is the difference in the temperature at each of those points. Described as the air temperature differential, it measures the difference between the air going into the system and the air coming out.
The ideal differential should normally be somewhere between 14 and 20 degrees Fahrenheit. For example, if the air entering the system is 77 degrees, the air coming out should be between 57 and 63 degrees.
Checking the Air Temperature Differential
What temp should air be coming out of AC vents? Knowing what temperature air should be coming out of AC vents requires first knowing that an air conditioner is working correctly and efficiently. So, determining the air temperature differential is the essential first step.
The process that Leith Heating & Cooling uses includes these steps:
- Locate supply and return vents.
- Use an infrared thermometer to measure temperature while the air conditioner is running. An infrared or “non-contact” thermometer accurately measures ambient air temperatures without contacting solid objects.
- Measure the air temperature at the return vent.
- Measure the air temperature at the various supply vents located around the house.
- Calculate the air temperature differential. To produce the differential, subtract the supply temperature from the return temperature. Make this calculation at each of the supply vents throughout the house.
Troubleshooting Discrepancies in Air Temperature Differential Between Supply Vents
Analyzing any differences in the differential at various supply vents provides important information about overall AC system efficiency and can provide evidence of damaged ductwork or other supply problems.
Here are some of the possible causes for variations in air temperature differential at different supply vents.
Blocked or Closed Vents
If vents are physically blocked by solid debris or obstructed by closed or partially closed vents, the cool supply air cannot efficiently circulate and will flow to other parts of the ductwork or be lost to leakage.
Dirty Return Air Filters
A dirty or clogged return air filter is a common problem that affects air conditioner efficiency. The filter that fits over the return vent should be changed according to manufacturer recommendations, typically every 30 to 90 days.
Clean, high-quality air filters enable your air conditioner to function correctly and help provide better air quality by removing allergens, dust, and debris from your air supply.
Ductwork Problems
Faulty ductwork can lead to a supply vent that fails to provide adequately cooled air. Leaky ducts rapidly lose cool air, as hot outside air underneath your home quickly exchanges through a leak for the cool air you are spending energy on creating.
If you are cooling the outside air through a leak, it stands to reason that it will be very difficult for your system to properly cool your inside air.
Damaged or Insufficient Insulation
Damaged or inadequate insulation also leads to heat pouring into your home or back into your cooled air before it reaches the supply vents. Pests, flooding, and weather can destroy insulation. In some cases, we have seen that homes pass inspections even though insulation is insufficient or missing.
The Value of Regular HVAC Maintenance in Elgin, IL
Regular Professional maintenance of your cooling and heating system is critical to optimal performance and energy efficiency. Leith Heating & Cooling recommends servicing twice each year — once for the air conditioner before summer and again for the heating system before winter.
In addition to calibrating your thermostat and checking air temperature differentials, we clean the coils, check and top off refrigerant levels, and ensure all the components are in good shape and working properly.
A properly maintained air conditioner is far more likely to produce balanced and consistent cooling power with the best possible energy efficiency.
If air temperature differentials at your supply vents do fall out of line in between routine maintenance services, we can diagnose whatever issues have developed and advise you on proper solutions. Sometimes, thermostat failure, compressor malfunction, or other issues can crop up despite regular maintenance.
Our service work will help you protect your rights under your manufacturer’s warranties.
Call Leith Heating & Cooling for Complete Air Conditioning and HVAC Service in Elgin, IL
What temp should air be coming out of AC vents? Now that we’ve discussed that topic, we invite you to look through our website and blog for more information about heating and cooling repairs, HVAC installation, ductwork repair and replacement, and all the indoor comfort services we provide in Elgin and the surrounding area.
Our licensed and EPA-certified technicians are ready to assist, and we guarantee your satisfaction with every job we perform. Call Leith Heating & Cooling today at 847-851-8698 to schedule prompt and friendly service.