What happens on site when we install HRV or ERV
East-metro growth stock and river-adjacent ranches around Cottage Grove do not fail at the brochure stage — they fail when outdoor hoods, drains, and balance get improvised. Here is the day-of sequence, and the exact moment we lock heat-only vs heat-plus-moisture recovery.
No twin comparison cards on this page — just the job as crews actually run it in Cottage Grove mechanical rooms and conditioned garages.
Before the truck arrives
You send build era, river-bluff vs inland plat, window/sealing projects, and whether January feels damp or arid. We propose HRV or ERV on the quote — not after drywall dust is airborne. Photos of the mechanical space and existing exchanger (if any) shorten the visit.
Hour-by-hour on install day
Arrival & protection
Crew protects floors, confirms outdoor termination sides (prevailing winter wind matters near open Mississippi valley edges), and verifies condensate route options.
Demo / clear the bay
Old exchanger out if this is a replacement. We note ice history and filter neglect — clues if the prior core type was wrong for the envelope.
Mount, duct, drain, controls
Cabinet hung or platformed, outdoor air and exhaust hoods set, drains trapped, controls wired to the agreed continuous rate.
Balance & handoff
Measured supply/exhaust, filter sizes written down, and a short owner briefing on winter RH targets for your core type.
When HRV vs ERV gets chosen (mid-quote, not mid-drywall)
On Cottage Grove post-code plats that already feel bone-dry, the quote locks ERV. On sealed older river-edge homes with fogged north glass, it locks HRV. If a homeowner insists on the opposite core without RH evidence, we document the risk rather than guess on install morning.
Why we refuse mid-drywall core flips
Changing HRV to ERV after penetrations are cut wastes a day and usually means the symptom interview was skipped. East-metro rebuilds and finished basements move fast; locking the core on the quote protects your schedule and our balance numbers. If RH evidence arrives late, we reschedule the cabinet — we do not gamble with the wrong core in a finished mechanical room.
River-edge wrinkle
Mississippi valley wind and shoulder-season outdoor humidity change hood placement more than they change core physics. Comfort expectations are higher in newer plats — quieter cabinets and careful vibration isolation show up in the scope.
Coordination with basement finishers and GCs
When Cottage Grove basements close up, we prefer locking HRV vs ERV before exterior sheathing or rim-joist work closes outdoor hood options. Send the GC or finisher contact on the form if sequencing matters. We will not show up to "figure out the core" while painters are masking trim.
What you do during the day
Keep pets secured, clear the mechanical path, and be available for a mid-day RH conversation if readings surprise us. Most Cottage Grove jobs do not need you home the entire time after the kickoff walk.
How long is a typical Cottage Grove install day?
Clean replacements often finish in a day. New ducted outdoor-air runs on finished ranches can span more depending on attic access.
Will you decide HRV vs ERV only after opening walls?
Core type is usually locked at quote from symptoms and envelope notes. Mid-job switches are rare and only if RH evidence contradicts the plan.
Book the Cottage Grove install quote
Tell us replacement vs new, river-edge or inland, and damp vs dry winters. We lock HRV or ERV before crew day.