#708: Controlling Indoor Humidity, Swelling Hardwood Flooring, and ERV vs. HRV

Prioritize airtight ductwork and correctly sized AC units to manage indoor humidity effectively, especially in humid climates, as oversized units can exacerbate problems.

Invest in quality diagnostic tools like an infrared camera, surface moisture monitor, and temperature/RH/dew point monitor to accurately identify moisture issues, or consider renting them for specific projects.

For new construction or renovations, consider using third-party HVAC designers like Allison Bail's company to ensure optimal system design, rather than relying solely on installers.

When selecting an HRV or ERV for cold climates, ensure it's specifically rated for those conditions (tested at 13 degrees Fahrenheit) to prevent performance issues.

If using a ventilation system for both general air exchange and spot ventilation (like bath fans), double the unit's size to accommodate the extra air-pulling capacity needed in boost mode.

Be mindful of the potential for moisture intrusion from unconditioned spaces like garages into conditioned living areas, as this can lead to significant issues like hardwood floor swelling.

If you have high indoor humidity and a variable-speed heat pump, explore options like electric reheat to overcool and dehumidify effectively without making the living space uncomfortably cold.