MECHANICAL ENGINEERING
Heating & Cooling Load
Calculations
Room-by-room and block load analysis that gives your engineers a reliable foundation
for equipment selection and system design.
Our Founding and Mission
Introduction
Accurate load calculations are the starting point for every HVAC design decision that follows — equipment capacity, duct sizing, and hydronic pipe sizing all depend on them. NexMEP Global LLC provides heating and cooling load calculation support to U.S. MEP consulting firms, preparing room-by-room and block load models using the building envelope data, occupancy schedules, and internal gain assumptions your engineering team provides.
Our role is to produce complete, well-documented load calculation packages that your engineers review, adjust, and approve before they become the basis of design. We do not select assumptions on your firm’s behalf; every envelope value, occupancy density, and internal gain figure we use is sourced from your team’s design documentation or confirmed with your engineer before it enters the calculation.
WHY LOAD CALCULATIONS
Why This Service Matters
Undersized or oversized HVAC equipment creates problems that persist for the life of a building: comfort complaints, poor humidity control, short-cycling equipment, and unnecessary energy consumption. Load calculations that are rushed or built on incomplete envelope data tend to produce these outcomes, and correcting an equipment sizing error after construction is far more costly than getting the calculation right during design.
Because load calculation work is detail-intensive and time-consuming — particularly on projects with complex glazing, multiple orientations, or varied occupancy types — it is often the first task delayed when internal engineering staff are stretched across several active projects. Production support keeps this foundational step on schedule without asking your engineers to rush it, and gives them a complete, well-documented package to review rather than a partial calculation requiring significant additional time to finish under deadline pressure.
Our Capabilities
Room-by-Room Loads
Detailed heating and cooling loads for individual rooms and spaces.
Block Load Analysis
Building and zone-level load summaries for system planning.
New Construction
Load calculations for new commercial and residential projects.
Renovation Projects
Updated loads for additions and existing building modifications.
Comparative Studies
Analysis of alternate envelope and system strategies.
Tenant Improvements
Updated load calculations for specific suites and floor areas.
Calculations
Engineering Calculations
Calculation methodology built for accurate, traceable HVAC equipment sizing.
Room & Zone Load Analysis
Our load calculation work follows ASHRAE Fundamentals methodology, using industry-standard software platforms compatible with your firm’s preferred tools. We calculate sensible and latent cooling loads, heating loads accounting for design outdoor air conditions, ventilation loads per ASHRAE 62.1 or applicable code, and solar heat gain through glazing based on orientation and shading conditions.
Block & Diversity Analysis
Where your engineer requires diversity factors applied to block loads for central plant sizing, we apply the diversity methodology your firm specifies and document the resulting reduction from the sum of individual room peaks, so the basis for central equipment sizing is transparent and traceable during your review.
Calculations
Systems We Support
Load calculation support across a range of HVAC system configurations.
Packaged Rooftop Units
Split Systems
VRF / VRV Systems
Fan Coil Systems
Air Handling Units
DOAS
Hydronic Systems
Mixed System Types
Load calculation support applies across all HVAC system types your engineers may select, including packaged rooftop systems, VRF, hydronic fan coil and air handling unit systems, and dedicated outdoor air systems. We adjust calculation inputs to reflect the ventilation and system-specific requirements of each configuration, including outdoor air percentages, economizer operation, and demand-controlled ventilation strategies where your design incorporates them.
For projects with mixed system types serving different zones of the same building, we maintain separate but consistently formatted load summaries for each zone, so your engineer can review equipment selections zone by zone without reconciling inconsistent calculation formats.
Calculations
Software, Workflow & Coordination
Rigorous backup calculations formatted directly for permit submission and QA/QC documentation.
Software & Production Workflow
Load calculations are prepared using industry-standard load calculation software compatible with your firm’s tools and export requirements, with input files and reports organized to match your project’s file structure. We coordinate directly with your architectural team’s envelope data and your engineer’s system narrative, flagging incomplete or inconsistent input data before calculations are finalized rather than making assumptions on your behalf. Our workflow includes a documented input log recording the source of every envelope, occupancy, and internal gain value used, so your engineer can trace any calculation result back to its originating design document during review or plan check.
Revit & AutoCAD Coordination
Where your firm models building geometry in Revit, we extract room and space data directly from the model to maintain consistency between the architectural floor plans and the load calculation room list, reducing the risk of mismatched square footage or omitted spaces. Final load results are formatted for direct reference in equipment schedules placed on your construction drawings. When architectural geometry changes during design development, we re-run affected room and block loads against the updated model and flag any resulting changes to previously issued equipment capacities for your engineer’s review, rather than allowing outdated load data to persist in the drawing set.
Calculations
Systems We Support
Expertise across diverse equipment lines, hybrid configurations, and complex mechanical setups.
Room-by-Room Load Reports
Block Load Calculation Reports
Equipment Scheduling Tables
Input Assumption Documentation
Comparative Load Analysis
Calculation Change Logs
Permit & Peer Review Packages
Calculation Backup Packages
Need Additional Load Calculation Capacity?
Add dependable room-by-room and block load calculation production support to your engineering workflow without increasing the burden on your internal team.
Our Core Philosophy
Typical Project Types
Commercial
Office buildings and commercial facilities requiring accurate heating and cooling load calculations for efficient equipment sizing and system design.
Education
Load calculation support for K-12 schools and higher education facilities with varied occupancy schedules, building uses, and ventilation requirements.
Healthcare
Heating and cooling load analysis for healthcare and outpatient facilities where building use, occupancy, ventilation, and system requirements require careful coordination.
Renovation & Tenant Work
Updated load calculations for renovation, phased development, and tenant improvement projects where existing conditions and new design requirements must be evaluated together.
Calculations
QA/QC Process
A rigorous, multi-tiered review structure ensuring accurate, clear, and error-free submittals.
Input Verification
Envelope, occupancy, and internal gain data are checked against the engineering team's source documentation.
Calculation Review
Room-level and block-level totals are reviewed for internal consistency and cross-checked against equipment capacities.
Independent Check
A secondary reviewer spot-checks calculation results and repetitive unit types for accuracy and consistency.
Why NexMEP Global LLC?
Our load calculation team understands that this deliverable sets the foundation for every downstream HVAC decision. NexMEP Global LLC applies a consistent, documented methodology, U.S. code and standards focus, and multi-level QA/QC review to every load package, giving your engineers a dependable basis for equipment selection.