FAQ
Q1: How do I know if my airflow issues stem from dirty ducts or an undersized HVAC unit?
An undersized HVAC unit runs continuously without reaching your thermostat setpoint across the entire home. In contrast, duct restrictions cause localized temperature disparities, whistling sounds near grilles, or weak air velocity at specific distant vents while nearby vents blow strongly.
Q2: Why did ASHRAE update residential filter standards to MERV 11?
The 2025 update to ASHRAE Standard 62.2 raised the minimum residential filter standard to MERV 11 to capture fine respiratory particulates and urban pollutants better. Modern MERV 11 filters offer refined media weave that captures smaller contaminants without causing harmful pressure drops on modern variable-speed blowers.
Q3: How much does professional air duct cleaning cost, and is it necessary?
Professional air duct cleaning costs average between $300 and $600, or about $25 to $50 per vent. Schedule professional cleaning if you notice visible mold inside metal ducts, major rodent or pest debris, or severe dust blockages following a major home remodeling project.
Q4: Will closing supply vents in unused rooms lower my energy bills?
No, closing supply vents increases static pressure within your ductwork. This extra pressure forces conditioned air out through unsealed duct seams and forces your HVAC blower motor to work harder, increasing energy consumption and accelerating equipment wear.
Q5: What is the ideal indoor humidity range for healthy airflow?
Maintain relative humidity between 30% and 50% year-round. Humidity above 60% makes air feel heavy and stuffy while encouraging mold growth, whereas humidity below 30% leads to dry skin and nasal passages.
