ASHRAE 62.2 is the consensus standard for ventilation and acceptable indoor air quality in low-rise residential buildings. It answers a question modern, tightly built homes can't ignore: how much outdoor air does a house actually need? Older, leaky houses ventilated themselves through gaps; today's air-sealed homes often don't, which is why mechanical ventilation has become part of good IAQ design.
The standard's core is a whole-house airflow target. In US units the required continuous rate is roughly 0.01 × the conditioned floor area in square feet, plus 7.5 CFM for each bedroom plus one. A 2,000-square-foot, three-bedroom home works out to about 50 CFM of continuous fresh air. The standard also covers local exhaust — bath and kitchen fans — and how intermittent fans count toward the total.
You won't size your own system, but 62.2 gives you a way to judge a quote. A contractor proposing an ERV or HRV or a supply-ventilation setup should be able to state the CFM target they're hitting and why. A bid that adds a ventilator with no airflow number behind it is guessing. The standard is what turns 'fresh air' from a sales word into a measurable design figure.