Imperial’s return air grilles solve a basic HVAC need with three distinct models that differ in ways that actually matter for installation. The lineup includes two steel options (RG0019 and RG0385) and one polystyrene model (RG3010), each fitting the same 12x6 inch duct opening but with critical differences in margin depth and material properties.
The margin turnback depth determines how the grille sits against the wall — RG0019 features a deeper 7/8 inch margin turnback compared to the 3/16 inch margin of the RG0385 and RG3010 models. That extra 11/16 inches affects both aesthetics and clearance requirements. The deeper turnback on the RG0019 creates more shadow line and visual depth but requires more wall clearance during installation.
Material Differences That Matter in Montana Basements
The polystyrene RG3010 offers rustproof and scratch-resistant properties with rounded corners for safety — features that make sense in moisture-prone Montana basements where condensation and humidity create problems for steel grilles. Steel models get a durable powder-coat finish that handles normal conditions fine, but polystyrene wins in bathrooms, laundry rooms, and below-grade applications where rust resistance matters more than theoretical durability.
Metal models are suitable for standard use; polystyrene models are ideal for moisture-prone areas due to rustproof properties. The material choice isn’t about good versus better — it’s about matching the grille to the environment.
Installation and Specifications
All three models share identical fin geometry — 1/3 inch spaced fins set at 20 degree angle — providing consistent airflow characteristics regardless of material choice. The grilles fit standard 12x6 inch duct openings and are suitable for sidewall or baseboard applications.
| Specification | RG0019 (Steel) | RG0385 (Steel) | RG3010 (Polystyrene) |
|---|---|---|---|
| Material | Steel | Steel | High-density polystyrene |
| Margin Turnback | 7/8” | 3/16” | 3/16” |
| Fin Spacing | 1/3” | 1/3” | 1/3” |
| Fin Angle | 20° | 20° | 20° |
| Finish | Powder-coat | Powder-coat | Natural polystyrene |
| Special Features | Deep margin | Standard margin | Rustproof, rounded corners |
Customer Ratings and Real-World Performance
Customer satisfaction consistently runs high across the Imperial lineup. The RG0019 earned a 4.6 rating from 25 reviews, while the polystyrene RG3010 scored 4.9 across 16 reviews.
The differences between models reflect material properties and manufacturing complexity more than performance variations. All three models deliver the same basic function — allowing return air flow while blocking larger debris.
Frequently Asked Questions
Q: What’s the actual difference between 7/8” and 3/16” margin turnback?
The margin turnback is the lip that overlaps the wall opening. The RG0019’s 7/8” turnback covers more wall surface around the duct opening, hiding rough cuts and creating a more pronounced frame effect. The 3/16” models sit nearly flush, requiring cleaner wall cuts but providing a lower-profile appearance.
Q: Should I use steel or polystyrene in a bathroom?
Polystyrene. Montana bathrooms see temperature swings that create condensation on metal surfaces. The RG3010’s rustproof properties eliminate the corrosion risk entirely, and the rounded corners reduce the chance of injury in tight spaces.
Q: Do these grilles restrict airflow compared to cheaper stamped versions?
The 20-degree fin angle and 1/3” spacing provide good airflow while maintaining directional control. These aren’t high-velocity registers — they’re return grilles designed for low static pressure applications.
Q: Are mounting screws included?
Standard mounting screws are typically included as a standard accessory, though not explicitly mentioned in product descriptions. Have self-drilling drywall screws on hand as backup.
Q: What about warranty coverage?
No manufacturer warranty is explicitly detailed. Retailer-specific return policies include 30-day windows at some retailers and 90-day windows at others. These are simple mechanical products — if they’re not damaged in shipping, they’ll work for decades.
Ready to Get Started?
Our building materials specialists can help you find the right Imperial products for your project.
More from Imperial
Explore All Imperial Products
We carry Imperial across all 11 Montana and Idaho stores.
