Inlet Only · No Motor · No Power · Fixed or Removable Screen
OOH All-Weather
OOH All-Weather
Inlet Hood
Passive Fresh Air Intake Termination · Fixed or Velcro Screen · 4"–12"
✓No motor, no wiring, no control sequence — install at the wall and it's done
✓Fixed screen — permanent ¼" mesh, regular metal default, standard installation
✓Velcro screen — removable ¼" mesh, painted white default, cold climate and seasonal maintenance
✓Both types available in regular metal or painted white — specify at order
✓Sizes 4"–12" standard · 10-year mechanical warranty
Is this the right product?
✔ Right product if
You need a passive inlet hood for a fresh air intake duct termination at the building exterior — no motor, no power, clean weather-resistant termination. Damper control is handled by an inline HAC in the duct run.
✗ Not this product if
Exhaust outlet application → use BDH Back Draft Hood
Motorized open/close control at the wall → use MOH Motorized Hood
Intake must seal when system is off → pair with HAC inline damper or use MOH
Motorized open/close control at the wall → use MOH Motorized Hood
Intake must seal when system is off → pair with HAC inline damper or use MOH
What It Does
Sometimes the right solution is no motor, no wiring, and nothing to fail. The OOH does exactly one job — and keeps doing it for as long as the building stands.
The OOH is a passive all-weather inlet hood for fresh air intake duct terminations at the building exterior. No motor, no actuator, no wiring, no control sequence. Install it at the wall penetration, connect the duct on the interior side, and it's done. The hood keeps rain, debris, and pests out while allowing outdoor air to enter freely whenever the connected ventilation, combustion air, or make-up air system calls for it.
The OOH is a fixed hood — it does not open or close and does not respond to a control signal. When the duct behind it is open, outdoor air flows in through the screen. When the duct is closed by an inline motorized HAC damper, no air flows — but the hood itself stays in position regardless. For Canadian and US residential new construction fresh air systems, the OOH at the wall paired with a motorized HAC inline in the duct is the standard code-compliant approach.
The OOH does not include a damper. It is always open to outdoor air. For motorized open/close control at the wall, use the MOH Motorized All-Weather Hood. For damper control in the duct run, pair the OOH with a HAC inline damper or HAC-L for cold climate installations.
Fixed Screen vs. Velcro Screen — The Primary Selection Decision
In mild climates this is largely an aesthetic preference. In Canadian and northern US climates it's a maintenance decision.
Fixed Screen — Use When…
✓Standard installations in mild to moderate climates
✓Set-and-forget install with no planned screen maintenance
✓Sheltered location or south-facing wall with low icing risk
✓Default finish: regular metal (painted white available at order)
Velcro Screen — Use When…
→Cold climate — Canadian or northern US with frequent freeze-thaw cycles
→Exposed location — north-facing wall or prevailing wind exposure
→Seasonal screen cleaning is expected to be a recurring task
→Duct may be repurposed from intake to exhaust in future
→Default finish: painted white (regular metal available at order)
When in doubt in a cold climate, specify the Velcro type. The cost difference is small. A fixed screen that ices over reduces fresh air intake area and can block flow entirely in severe conditions. The Velcro screen comes off in seconds — clean it, clear the ice, and reinstall. The Velcro type can also be converted to outlet use by removing the screen entirely. A fixed-screen OOH cannot.
OOH vs. MOH — Passive vs. Motorized at the Wall
One question determines which product belongs on the job: does this intake need to seal when the system is off?
| Condition | Use OOH | Use MOH |
|---|---|---|
| No power at the wall location | Yes — no wiring needed | No — requires 24 Vac |
| Intake must close when system is off | No — OOH is always open | Yes — motorized close on shutdown |
| Budget-sensitive application | Yes — lower cost, no wiring | No — higher cost, wiring required |
| Retrofit with existing inline damper | Yes — pair with HAC inline | Either — replace both hood and damper |
| HRV/ERV fresh air port | Yes — standard termination | Either — MOH if powered close required |
| Combustion air interlock required | No — use HOM or MOH + ADP | Yes — MOH with end switch + ADP |
Key Specs
Application
Inlet only — fresh air intake
Types
Fixed screen / Velcro removable screen
Screen
¼" mesh — fixed or removable
Sizes
4", 5", 6", 7", 8", 9", 10", 12"
Finish
Regular metal or painted white — specify at order
Power Required
None
Operation
Passive — always open when duct is open
Warranty
10-year mechanical
Common Questions from the Counter
Answers to what comes up most when specifying the OOH.
Can I use the OOH for an exhaust outlet?
The fixed-screen OOH is inlet only and cannot be used as an exhaust outlet — the screen traps lint, debris, and moisture on exhaust applications and the hood geometry is designed for intake airflow. The Velcro-screen OOH can be converted to outlet use by removing the screen entirely, but the hood body is still inlet-geometry. For a dedicated exhaust outlet, use the BDH Back Draft Hood. For motorized control handling both intake and exhaust, use the MOH Motorized All-Weather Hood.
Does the OOH include a damper?
No. The OOH is a passive hood with no damper function — it is always open to outdoor air. Damper control is provided by a separate motorized inline damper in the duct run, typically a HAC or HAC-L — or by the MOH Motorized All-Weather Hood if motorized control at the wall is preferred. If the intake needs to close when the system is off, pair the OOH with a motorized HAC inline, or replace the OOH with a MOH.
Do I need the Velcro type if I'm in a cold climate?
Not always, but it's worth considering. If the intake is in a sheltered location, south-facing wall, or low-humidity environment where icing is unlikely, the fixed screen is simpler and equally effective. If the intake is exposed to prevailing winds, north-facing, or in a climate with frequent freeze-thaw cycles, the Velcro screen pays for itself the first time you need to clear a blocked screen without a screwdriver. The cost difference between the two types is small. When in doubt in a cold climate, specify the Velcro type.
What size OOH do I need?
Match the OOH diameter to the fresh air duct diameter at the wall penetration. Standard residential fresh air intake is typically 5" or 6" for a single-family home. HRV and ERV fresh air ports are typically 5" or 6" depending on unit capacity. Make-up air inlets for commercial kitchen exhaust may be larger — 8" to 12" depending on exhaust volume. If the duct transitions to a different size near the wall, match the OOH to the duct diameter at the wall, not at the appliance.
Is the OOH the same as the HOM?
No. The HOM is a motorized combustion air damper — a 24 Vac product that installs inline in the duct run and controls combustion air flow to fuel-burning appliances. The OOH is a passive exterior hood with no motor and no damper function. The OOH can be paired with a HOM or HAC inline damper in the same duct run — the OOH terminates the duct at the exterior, and the HOM or HAC controls when air flows.
Ready to Order
OOH — All-Weather Inlet Hood
Select your size, type (fixed or Velcro screen), and finish (regular metal or painted white) — then add to cart. Cold climate installs: Velcro screen recommended.
Configure & Order →
Size · Type · Finish
Need help specifying the OOH?
Available through your Hoyme wholesaler. Contact Hoyme direct for sizes outside the standard range.