A grain storage and drying combination, GSI’s TopDry systems offer up to 2000 bph drying and storage up to 29000 bu. A layer of grain on the overhead drying chamber is dried by a large fan and heater then dumped to a holding area below. A smaller aeration fan below captures heat from this previously dried grain, and pushes it upward to help dry the next load. This recycling of heat increases efficiency, which greatly reduces drying costs.

Over the years, universities, and farmers alike have repeatedly proven that “in-bin” drying is one of the most efficient methods of drying grain. TopDry goes one step further by integrating features that allow filling, drying and dumping operations to be run automatically for extreme efficiency. Because TopDry is also a storage bin, crops can be stored on site, then sold at a later date for potentially better returns.

TopDry Systems

TopDry Sidewalls and Roofs

TopDry Sidewalls and Roofs

TopDry utilizes strong vertical stiffener columns to cary the vertical load of the bin and system to the foundation. Stiffeners are manufactured from high strength 65,000 PSI (450 MSA) steel. The stiffeners are mounted on the outside of the tank to allow for unimpeded grain flow inside and feature strong splice joints and a large cross sectional area.

The 4″ wide corrugated sidewall design is standard on the GSI TopDry system. The 44″ tall sheets are constructed using 65,000 PSI minimum, high tensile steel for a strength and solid support. All sidewalls feature G-90 bright divgle galvanized coating to ensure a long tank life. GSI also uses graded, zinc plated, high strength, dichromate bolts at all connections. Each bolt has a special sealing washer to keep out the elements. Bolts with polypropylene coated heads are also available as an option.

Just as with the corrugated sidewall sheets, GSI fabricates TopDry roofs out of prime, high tensile, G-90 galvanized steel. Each roof rib is roll formed with triple ridged rib sides for strength. In addition, a shallow corrugation in the flat area between roof ribs is added for increased rigidity. Roof ribs are fully double lapped to help keep the weather on the outside of the bin.

Roof Vents

GSI offers two unique vents to meet your ventilation requirements. The hinged grill vent features a vertically mounted, large mesh, wire formed screen to keep out pests and swings freely open to allow easy release of trash buildup. The Auto-Vent is designed to reduce “plugging” or air restriction through the use of a special wing-shaped damper. When fans are running, air passes freely above and below this damper allowing it to float open in mid air. The damper drops down and closes when the fan is not in operation to help block out wind, snow, birds, etc. from entering.

Both vents are assembled with a heavy duty locked seam and for additional protection, a die-cut gasket is placed between the vent and roof panel to further decrease water penetration. GSI provides roof panels with an exclusive factory-prepunched, extruded lip for each vent.

Optional full circle roof rings are available for additional convenience when working on or inspecting the tank roof.

Grilled Vent

Grilled Vent

Auto Vent

Auto Vent

TopDry Bin Access

Sturdy doors, sidewall ladders, ladder cages and platforms provide easy access when entering, exiting or inspecting the TopDry Bin.

Bin Ladders

Ladder sections have roll formed sides and “swedged” rungs to provide high strength, stability and quick assembly. Sections are available in 48″ lengths and feature specially designed dimpled rungs for a better grip.

Ladder Cages

All ladder cages are completely galvanized, bolt directly to the prepunched sidewall ladder and feature a bell opening at the bottom of the cage allowing ample space when entering and exiting the ladder.


An eave platform can be constructed below the manhole for your convenience when entering the bin or inspecting the roof. The platform is die formed from galvanized steel and machine stamped with a tread grip pattern.


Accessing the top of your bin has never been easier than with GSI’s winding bin stairs. Stairs feature all galvanized construction, interlocking handrails, and heavy duty bolted construction for easy field installation, both during initial construction or retrofitting on existing tanks. The steps large and integrated toeboard give you a solid, dependable path to the top. Stairs are available for tanks 18′ to 105′ diameter and can circle to the right or the left.

Access Door

All inner door panels on GSI’s walk through door open completely with no horizontal bars or braces to unbolt or remove. Specially designed lever latches multiply the inner door opening force by 20 times to counteract friction set from grain loads, requiring no use of wrenches or tools. Other features include a probe opening for easy grain inspection and factory caulked door frames reducing installation time. GSI’s patented two ring door is standard on all bins up to 9 rings tall and an option on other heights.

A heavy-duty 24″ diameter access door is also available and standard on some taller Farm-Com bins. As an option, a heavy gauge, galvanized step can be ordered as well, providing a step-up to doors or other hard to reach areas.

Plenum Access

Optional plenum cleanout panels provide additional convenience for plenum cleanout or floor inspection.

Sturdy Bin Ladders

Ladder Cages


Easy Access Door

Round Door

TopDry Series 2000 Fans and Heaters

TopDry’s Series 2000 fan and heater combination is taking grain conditioning into the next century with computerized components that allow the operator better control and access to vital information. The TopDry specially designed heaters feature backlit LCD displays for night viewing, providing constant read-outs of plenum temperature, grain temperature, or drying time. Drying can be controlled manually by Time or automatically by temperature based moisture control. Built-in flame detection circuitry notifies the operator of emergency situations and shuts down the dryer in the event of a dryer malfunction. TopDry fans utilize a high efficiency, light weight, composite blade for reduced motor stress at startup. A clear view panel on the side of the housing provides easy access to the burner for ignitor and flame probe adjustment or burner disassembly for cleaning and inspection. Vinyl fan covers are standard to completely enclose fan openings preventing weather or other unwanted material from entering the bin. TopDry fans and heaters are available in 36″ dia. (15 HP) up through 42″ (40 HP). All single phase TopDry fans have single rotation motors to prevent the fan from rotating backwards.

Fans and Heaters

Built-in Thermostat

GSI 2000 series fans and heaters offer a built in thermostat for plenum and grain temperature, with the plenum and grain temperature, with the plenum thermostat differential being adjustable and programmable from the ground. The sensor is mounted in a weather proof “UL” approved housing, impervious to weather, rodents and insects.

TopDry Cooling Fans

For TopDry systems, GSI offers a 36″, 40″ and 42″ diameter vane-axial fan in 12 to 40 HP. These units utilize a heavy-duty 1750 RPM motor for increased fan performance and energy efficiency. GSI also manufactures a complete line of transitions to connect fans to the TopDry bin.

Built-in Thermostat

TopDry Autoflow Controls

The Autoflow Control System is exclusive to Maxim TopDry and available on all bin sizes from 18′ to 36′ diameter. Autoflow controls allow operation in automatic batch mode or continuous flow mode. In batch mode the Autoflow controls fill, dry and dump each batch automatically. During operation in continuous flow mode, the dryest one-third of the grain in the drying chamber is dumped and replaced with wet grain. The drying chamber is never completely empty and the wetter grain is always exposed to the higher temperature air. This results in higher drying rates and more consistent moisture removal throughout. Autoflow features automatic shutdown in the event of fill switch failure or empty wet supply, plenum high temperature protection, auger fill delay and automatic or adjustable staged starting of fans and heaters. The Autoflow monitors fan and heater conditions (8 total) indicating which unit to shut down in the event of a malfunction, controls multiple auger systems for installations without a wet hopper tank, and automatically closes chutes in the event of a power loss. Autoflow includes four sensors for grain moisture averaging (more sensors yield better accuracy), motor starters for fill systems, batch counter, reliable rotary fill switches (power paks mounted externally for easier service) and has a 25 memory recall to keep track of unit shutdown including dates and times. Autoflow control boxes can be installed in a separate location from the drying bin. This can help prevent dryer controls from being tampered with or vandalized. Autoflow also offers an optional “Watchdog” software package that allows all dryer operation to be monitored remotely through a personal computer.

TopDry Autoflow Controls

Optional Series 2000 Manual Control Center

This optional control center is available for use with the Series 2000 fan and heater units. This control center offers control of dry time, cool time and grain temperature (moisture). An Important feature of this control center is the ability to set plenum temperature and other settings remotely from the fan(s) from a more convenient location. Batch TopDrys include four sensors for grain averaging (more sensors = better accuracy).

Series 2000 Manual Controls