Install an HRV / ERV (Balanced Ventilation)

Install a balanced-ventilation HRV or ERV (HRV moves heat only; ERV also transfers moisture — pick per climate): duct the stale-exhaust and fresh-supply runs, BALANCE the two airflows to equal CFM, drain the condensate on an HRV, interlock/control it with the air handler, then verify the cross-flow core and the defrost cycle.

Approx. 240 min

Before you start

•HRV vs ERV chosen for the climate: ERV transfers moisture (keeps humidity in during winter / out in summer — better for hot-humid and very-cold-dry homes); HRV transfers only heat (good where humidity control isn't the issue).
•Ventilation rate sized to the home (per the design / code ventilation rate), and the four duct paths planned: outdoor fresh-air intake, fresh supply into the house, stale return pickup, and stale exhaust to outdoors.
•Mounting location with a condensate drain available (HRVs condense and need a trapped drain), a power source, and a control/interlock plan with the air handler.

Tools & materials

Sheet-metal/duct tools, insulated duct for the outdoor runs, foil tape/mastic · Balancing tool (flow hood / anemometer / pitot + manometer), balancing dampers · Condensate tubing + trap (HRV), drill/screws, low-voltage wire, multimeter · HRV/ERV unit, exterior intake + exhaust hoods with bird screens

View

0% complete

Mount & duct the four paths

Hang the unit and plan drainage
Hang the HRV/ERV level on its brackets/straps with service clearance to pull the core and filters. Verify power off before wiring later. On an HRV, plan the condensate drain location now.
⚠ Verify power off before any electrical connection to the unit.
Run the fresh and stale ducts + exterior hoods
Duct the four paths: outdoor fresh-air INTAKE and stale EXHAUST to separate exterior hoods (with bird screens, separated so you don't re-ingest exhaust), and the fresh SUPPLY + stale RETURN to the house. Insulate the two ducts carrying outdoor-temperature air to stop condensation/sweating, and seal all joints.
Tools: Insulated duct, Foil tape/mastic
Target: Intake/exhaust hoods separated with bird screens; outdoor-air ducts insulated; all joints sealed

Drain, power & control

Trap and route the condensate (HRV)
An HRV condenses water out of the warm stale air in winter — connect its drain to a trapped condensate line to a legal drain. (A true ERV core typically doesn't drain, but confirm the maker's requirement.)
Tools: Condensate tubing + trap
Target: HRV condensate trapped + routed to a legal drain (per the maker; ERV usually none)
Power and interlock with the air handler
Power the unit and wire its control/interlock: tie it to the air-handler blower / control so fresh air is distributed (and so it runs with the system or on its own ventilation timer/control), and land the wall control. A common method ties the supply into the return-air duct of the air handler.
Tools: Low-voltage wire, Multimeter
Target: Unit powered; controlled/interlocked with the air handler blower + wall control

Balance & verify

Balance the supply and exhaust airflows
Measure both airstreams and adjust the balancing dampers so the fresh SUPPLY and stale EXHAUST move EQUAL CFM — that's what makes it 'balanced' ventilation and keeps the house neither pressurized nor depressurized (which would backdraft combustion appliances or pull in unconditioned air).
Tools: Balancing tool, Balancing dampers
Target: Supply CFM = exhaust CFM (balanced) at the design ventilation rate
⚠ An unbalanced system can depressurize the house and backdraft gas appliances — balance it.
Verify the cross-flow core and defrost cycle
Run the unit and confirm both fans move air through the core (energy is exchanged in the cross-flow core — supply tempered toward room temp). In cold climates confirm the defrost cycle operates (recirculation/damper or fan cycling) so the core doesn't ice and block airflow.
Target: Both fans move air through the core; supply tempered by the core; defrost cycle operates in cold ambient