At Controlled Climate Services, we specialize in heating and cooling for residential and commercial clients in Kennesaw and throughout the Greater Atlanta area. We’ve encountered many persistent HVAC misconceptions over the years, but perhaps none of those misunderstandings is as pervasive as the notion that you can close vents in order to save money.
What Has Led to This Misconception?
Although it’s impossible to say exactly what led to the notion, we think it likely has to do with the levers that are included with most HVAC vents. Since you can open and close them, then it must be a good idea to do so, right? No. The option exists, but it’s not a good idea to use it unless you understand why.
HVAC Systems Are Balanced for Pressure
When we install an HVAC system system, the blower is chosen and calibrated to exert against a specific maximum pressure. This is why you have to change your air filters. As they get dirty, the blower works harder as the pressure increases, and that leads to an inefficient system that costs you more.
ECM vs. PSC
Not all systems are the same. Some systems use a permanent split capacitor, or PSC, and will provide less airflow as pressure increases. Other use an electronically commutated motor, or ECM, and will use more electricity as it ramps up in order to combat the additional pressure.
Closed Vents Create Pressure
So, while it may seem right that fewer vents mean less air and thus lower utility costs, that isn’t likely the case. Closing a vent will create additional pressure, and this means that you’re more likely to increase your electric bill than make it smaller.
The Unintended Consequences of Closing Vents
Closing vents will generally not save you money. The exception to this rule is a zoned system that features variable-speed ECM blowers. In such scenarios, the registers actually communicate with the system. In usual scenarios, however, you’re likely to cause unintended consequences, including:
- Lower airflow
- Increased energy usage
- Increase duct leakage
- Excess condensation
- Compressor problems
Looking to lower your energy costs? Call Controlled Climate Services today and let us help.