H-Sym (HSYM) simulates centralized HVAC hot- and chilled-water piping systems to determine pressure losses, operating pressures, water and air temperatures, flow rates, and obtainable unit loads across the entire network; it is intended for steady-state operational analysis rather than pipe sizing or equipment selection. Systems may include numerous component types—pipes, insulation, boilers, chillers, pumps, coils, heat exchangers, radiators, and 2- or 3‑way control valves—and the software supports large models with up to 3,000 pipe sections, 2,999 nodes, 20 chillers/boilers, 50 pumps, 500 coils/exchangers/radiators, and 500 valves. Two versions are offered: Hydraulics Only, or Full with heat transfer analysis; an optional pipe sizing feature is also available, and inputs can be entered in either English or metric units. HSYM provides rapid calculations, extensive input error checking, effective coil UA derivation from catalog data, automatic altitude adjustment of coil CFM, and equivalent fitting length lookups, with comprehensive input and output reports for documentation.

Key Features

Whole-network hot/chilled water simulation Steady-state analysis across complex systems.

• Calculates flows, velocities, pressures, temperatures, and obtainable loads.
• Intended for operational simulation rather than pipe/equipment selection.

Scales to large projects High component and node limits.

• Up to 3,000 pipe sections and 2,999 nodes; 20 chillers/boilers.
• Up to 500 coils/exchangers/radiators and 500 valves; up to 50 constant or variable speed pumps.

Hydraulics and heat transfer options Choose scope per need.

• Two versions: Hydraulics Only or Full with heat transfer analysis.
• Considers pipe insulation effects in hot-water systems.

Standards-aligned data handling Efficient, accurate inputs.

• Accepts English and metric units; instantaneous input error checking.
• Calculates effective coil UA from manufacturer catalog data.

Productivity aids Reduce manual lookups and errors.

• Automatic altitude adjustment of coil CFM values.
• Automatic equivalent length lookup for fittings; fast computations and robust error checks.

Benefits

Better design confidence and troubleshooting Validate performance before install or retrofit.

• Reveals pressure, flow, and temperature distributions to identify bottlenecks and imbalances.
• Tests design alternatives quickly to find reliable, lower-cost configurations.

Reduced rework and faster documentation Streamlined analysis and reporting.

• Comprehensive input/output reports document assumptions and results for reviews and submittals.
• Built-in lookups and error checking cut manual calculations and iteration time.