Mestek hsa12511 Horizontal Hydronic Steam Unit Heater

Product Description

The MESTEK hsa12511 is a horizontal hydronic and steam unit heater designed for forced-air space heating using hot water or steam as the heat source. Rated at 24.8 MBH at 200 degrees F, it delivers 580 CFM of airflow through a copper coil heat exchanger. The unit is powered by a 25-watt, 120-volt totally enclosed motor with a built-in thermal overload protector, making it suitable for demanding commercial and industrial environments. Connections are 1-1/4 inch FPT on both inlet and outlet. The system is rated for a maximum working pressure of 150 psi and weighs 25 pounds.

This unit heater is suited for commercial and light industrial applications where hydronic or steam heating infrastructure is already in place. Typical installations include warehouses, garages, utility rooms, and workshops. The horizontal configuration allows ceiling or overhead mounting, directing conditioned air downward and outward into the occupied space. A licensed HVAC technician or pipefitter is the appropriate trade for installation and commissioning.

Key Features

• 24.8 MBH output rating at 200 degrees F water or steam supply temperature
• Copper coil heat exchanger for efficient heat transfer and corrosion resistance
• 580 CFM airflow capacity for effective space heating coverage
• 25-watt, 120-volt totally enclosed motor with thermal overload protection
• 1-1/4 inch FPT inlet and outlet connections for standard hydronic or steam piping
• 150 psi maximum working pressure rating for compatibility with steam systems

Compatibility

Designed as an OEM-style replacement or direct-install unit heater for horizontal hydronic and steam heating systems operating at up to 150 psi.

Installation Notes

Installation should be performed by a licensed HVAC technician or pipefitter in accordance with applicable local mechanical codes and IFGC or IPC guidelines as relevant. Shut off and depressurize the hydronic or steam system completely before making any pipe connections. Ensure all FPT fittings are sealed with appropriate thread sealant rated for steam service. Power to the unit must be disconnected at the circuit breaker before any electrical work is performed on the motor or controls.

Technical Specifications

• Heating Capacity: 24.8 MBH at 200 degrees F
• Airflow: 580 CFM
• Voltage: 120 volts
• Motor Power: 25 watts
• Motor Type: Totally Enclosed with Thermal Overload Protection
• Heat Exchanger Material: Copper Coil
• Connection Size: 1-1/4 inches FPT Inlet and Outlet
• Maximum Working Pressure: 150 psi
• Weight: 25 pounds
• Orientation: Horizontal

Standard Information

• Brand: MESTEK
• Manufacturer Part Number: hsa12511