Most local guides to this decision start by placing your house somewhere on a town map. This one starts at the building itself and walks around it. A recovery ventilator puts two permanent holes through an exterior wall and then lives with whatever that wall does for the next fifteen winters, so the compass read is the part of the job most worth getting right before anybody drills. Here is what each face does on the Crow River edge of the county, and what it means for the install.
Furnace Direct installs licensed recovery ventilators in Rockford and the surrounding Wright and Hennepin countryside. No equipment is sold through this page; walk your four faces, tell us which are reachable, and a scoped install price follows.
Snow that lands here stays. Siding holds frost into the afternoon, grade stays frozen longest, and any horizontal termination on this wall is the one most likely to glaze over or disappear under a drift. Inside, the rooms behind this face are where condensation shows up first, which is exactly why they are the most honest place in the house to read humidity.
Verdict for a hood: Good for reading the house. Poor for a hood you want to forget about.
The warmest and driest wall by a wide margin, which sounds ideal and brings its own problem: repeated melting and refreezing at the bottom of the siding and anywhere water can pool on a flange. Terminations here stay clear of snow and need their flashing done properly, because they get wetted and frozen far more often than a wall that simply stays cold.
Verdict for a hood: Often the practical choice for an exhaust termination, with real attention to flashing.
This is the wall that gets driven snow packed into screens, that holds a measurable pressure difference during a storm, and that collects the long drift across an open rural lot. An intake on this face spends the winter being pressurised by whatever the weather is doing, which is not dangerous and is not quiet.
Verdict for a hood: Last choice for an intake unless nothing else is available.
Usually the best-behaved wall on the building. Low wind loading, modest sun, snow that lands rather than packs, and less melt-refreeze cycling than the south. On most houses in this part of the county this is where we would rather put the intake if the duct run allows it.
Verdict for a hood: First choice for an intake when the mechanical room can reach it.
Cold air is heavy and it runs downhill. On still clear nights it drains off the surrounding ground and settles in the low land along the river, which is why a house down near the water can sit noticeably colder at dawn than one a short rise above it, and why valley-bottom lots hold fog into the morning during the shoulder seasons. For a ventilator install, that means frost management at the terminations gets more attention on low ground: hood selection, mounting height above expected snow, and a pitch on the sleeve that sends condensate outward rather than back along the duct. Houses up on the shoulder get the opposite trade — warmer at dawn, windier all day, more driven snow on the west face. Neither position changes which core belongs in the cabinet.
Whichever room is tucked into the north-west corner of the building has the coldest interior surfaces, and vapor always finds the coldest surface before it finds any other. That makes that room the most sensitive humidity gauge you own. Read the bottom corner of its window at daybreak after a hard freeze. Water or frost there means the house is carrying more moisture than it can shed, which argues for a heat-recovery core. Plainly dry glass in a house that has been tightened, with a humidifier that never reaches its setting, argues for an energy-recovery core. One window corner, read correctly, outranks every orientation note on this page.
Narrow lots, close neighbours, and porches or shared drives eating two of the four faces. The compass read usually collapses to a single viable answer, and the constraint becomes clearance from the property line rather than exposure. We pick the wall before the day and build the duct route backwards from it.
All four faces are usable, which shifts the decision to drift and wind. Long open approaches load the west and north walls heavily, so the east face earns the intake and mounting height matters more than it does in town. The trade is distance: a wide footprint means a longer run to the wall you actually want.
Two reachable faces and one window-corner reading is a complete request.
Get a face-aware quoteThe technology. It is worth saying bluntly because the opposite claim sounds so plausible. Between November and March the outdoor air arriving at your intake is cold and very dry no matter which direction it came from, whether it crossed the river, an open field, or a neighbour's garage. The only meaningful source of winter indoor moisture is inside the building: the people, the showers, the cooking, the laundry, the lower level. A full household inside a tightened shell produces more vapor than the shell can lose and wants heat recovery. A quiet household inside the same shell loses faster than it produces and wants energy recovery. Four faces, one piece of physics, and the compass rose gets no vote.
You do not need a survey or a plan. Stand in the yard, work out roughly which way the house points, and tell us two things: which faces have a clear reachable wall near the mechanical room, and what is in the way on the others — a deck, a bay, a propane set, a neighbour's wall, a long soffit. Add which direction the room with the coldest window faces and what its glass does on a hard freeze morning. That combination lets us arrive with the right terminations rather than discovering the constraint from a ladder.
No, and we would be wary of anyone who said it did. Orientation decides which wall the hoods go on, how much flashing and freeze detailing they need, and how often you will be clearing a screen. The core is decided by what your household does to indoor air between November and March, which is the same on all four faces.
Because it is your instrument. The coldest interior surface in the building is behind that wall, and condensation always appears on the coldest surface first. If you want one place to look to find out whether your house is holding too much moisture, look at a north-facing window corner at daybreak.
Measurably, on calm clear nights. Cold dense air drains downhill and pools in the low ground, so a valley-bottom lot can sit several degrees colder than a lot a short distance above it, and it holds fog longer in the shoulder seasons. That affects frost management at the terminations. It does not change the core.
It is a detail, not a problem. We mount higher to stay above drift, choose a termination that can actually be cleaned, keep the two hoods properly separated, and tell you honestly that you will be looking at a screen once or twice a winter. Thousands of installs live on exposed walls and work fine.
Often yes, and sometimes that is the best answer — intake on the sheltered east wall, exhaust where the duct run is short. What matters is the separation between them, so the unit is not quietly drawing its own exhaust back in, and that the manufacturer's clearances are respected on both.
It truncates it. On the older tight-platted blocks you may have two usable faces rather than four, because the others are a shared drive, a neighbour's wall, or a porch. We settle hood locations before install day on those addresses rather than during it.
Which faces are reachable, what blocks the others, and what the coldest window does at daybreak.
Sibling pages work from a seven-line worksheet, an upgrade side-effect ledger, or a part-by-part inheritance audit of an old installation.