Bath Fans, Range Hoods, and Makeup Air: The Ventilation Problem Most Homes Have
A house is a system. You can't exhaust air without bringing fresh air in, but plenty of homes have bath fans, range hoods, dryer vents — and no plan for replacement air.
What ASHRAE 62.2 covers
The residential ventilation standard sets minimum continuous and intermittent ventilation rates for whole-house ventilation, local exhaust, and source control. The math gives you a target CFM — typically 60-90 CFM continuous or higher intermittent — based on bedrooms and floor area.
What most homes have
A bath fan. A range hood. A dryer vent. Sometimes an attic exhaust. Each one moves air OUT. None of them brings air IN — except by depressurizing the house and pulling air through wherever it can find a path (chimney, gas appliance vents, attic openings).
What it causes
• Back-drafting of gas water heaters and fireplaces (a real safety issue)
• Increased radon entry from below-grade openings
• Stale, dry air in winter (because dry outside air leaks in faster than the supply)
• High humidity in summer
• Negative comfort spread (cold spots, drafts)
What a balanced system looks like
A whole-house ventilation system — typically an ERV (Energy Recovery Ventilator) or HRV (Heat Recovery Ventilator) — brings filtered outside air in and exhausts stale air out in a balanced way. It recovers most of the heating or cooling energy in the process.
What this means for you
If your home was built in the last 15 years and feels stuffy or has high humidity, the ventilation is probably underbuilt. An ERV/HRV retrofit is not cheap but transforms the comfort and indoor air quality.
What contractors should know
Selling ventilation as comfort and IAQ — not as code compliance — is the angle that closes.
The part nobody can see later
Most of what decides how this holds up gets covered before the job is over. Once it is closed in, the only record of how it went in is the photos taken while it was still open.
Supervisr's HVAC Mechanical QA model works from common industry practice and the installation instructions that ship with the materials. It can review HVAC installation photos and documentation for load calc evidence, duct sizing and sealing, equipment sizing against actual load, refrigerant line set quality, condensate management, and ventilation rate compliance. Upload photos of the load calc paperwork, duct sealing and insulation, equipment label vs. load, refrigerant line set, condensate drain slope, ventilation CFM, and you'll get a documented evaluation back in minutes.
For a homeowner, that record is a straightforward way to understand what you paid for. For a contractor, it is the milestone documentation that stands behind a workmanship warranty years later, long after the crew has moved on to the next job.
About Supervisr
Supervisr is an AI quality-assurance platform for residential HVAC installations. It works from common industry practice and manufacturer installation instructions, and evaluates HVAC install photos and load-calc documentation to flag oversizing, duct issues, and ventilation shortfalls.
Contractors use Supervisr to document quality at each milestone — backing up a workmanship warranty and building a track record of work they can point to. Homeowners end up with a clear record of what went into their home. See how it works at supervisrapp.com.