Mechanical
1.Mechanical Design & Cost Estimating
- 1-1HVAC system design
- 1-2Ventilation system design
- 1-3Plumbing and sanitary system design
- 1-4Fire protection system design
- 1-5Water treatment system design
Service
Services
Zero Energy Building
Building services design aiming for ZEB (Net Zero Energy Building)
In October 2020, the Japanese government declared its goal of carbon neutrality: reducing net greenhouse gas emissions to zero by 2050.
"Net zero" means that emissions of carbon dioxide and other greenhouse gases, minus the amount absorbed through tree planting and forest management, add up to effectively zero.
ZEB stands for Net Zero Energy Building: a building that provides a comfortable indoor environment while aiming for a net annual primary energy balance of zero.
To design buildings that achieve ZEB, we work every day to improve our energy-saving technologies for building services.
ZEB Results
ZEB Orders Received
ZEB orders received (fiscal 2025)
ZEB design work
| Building size | Orders | Share | |
|---|---|---|---|
| New | Large (2,000 m² or more) | 0 | 0 % |
| Medium (300 to under 2,000 m²) | 0 | 0 % | |
| Small (under 300 m²) | 0 | 0 % | |
| Existing | Large (2,000 m² or more) | 0 | 0 % |
| Medium (300 to under 2,000 m²) | 0 | 0 % | |
| Small (under 300 m²) | 0 | 0 % | |
ZEB consulting work
| Building size | Orders | Share | |
|---|---|---|---|
| New | Large (2,000 m² or more) | 3 | 16 % |
| Medium (300 to under 2,000 m²) | 0 | 0 % | |
| Small (under 300 m²) | 1 | 7 % | |
| Existing | Large (2,000 m² or more) | 1 | 55 % |
| Medium (300 to under 2,000 m²) | 0 | 0 % | |
| Small (under 300 m²) | 0 | 0 % | |
ZEB orders received (fiscal 2022–2024, total)
ZEB design work
| Building size | Orders | |
|---|---|---|
| New | Large (2,000 m² or more) | 1 |
| Medium (300 to under 2,000 m²) | 2 | |
| Small (under 300 m²) | 0 | |
ZEB consulting work
| Building size | Orders | |
|---|---|---|
| New | Large (2,000 m² or more) | 8 |
| Medium (300 to under 2,000 m²) | 12 | |
| Small (under 300 m²) | 10 | |
ZEB orders received (fiscal 2021 and earlier)
- Location
- Mie Prefecture
- Project
- New hospital construction (name withheld)
- Structure / floors
- Reinforced concrete + timber / 3 stories
- Floor area
- 15,024 m²
Selected on July 31, 2020 for the fiscal 2020 subsidy to promote energy-efficiency investment (Sustainable open Innovation Initiative, SII).
Design
Building Services Design
Electrical
2.Electrical Design & Cost Estimating
- 2-1Power receiving and transforming system design
- 2-2Main feeder system design
- 2-3Lighting and outlet system design
- 2-4Low-voltage system design
- 2-5Fire safety and security system design
- 2-6Solar power system design
Building Information Modeling
We design with BIM (Building Information Modeling) CAD, building 3D models as we go.
Benefits of 3D models
- 1Clients can understand the building services visually.
- 2Clashes between architecture, structure, mechanical and electrical systems can be identified accurately.
- 3Quantities are taken off automatically, making cost control easier.
- 4Static pressure and pump head calculations can be automated.
- 5The model is the base data for CFD (computational fluid dynamics).
- 6The model can be handed over for construction management and maintenance.
— and many more.
Looking ahead, we expect BIM to extend into automated design with AI and automated energy calculations, and we aim to make the most of its value.
Computational Fluid Dynamics
We analyze HVAC and ventilation airflow with the OpenFOAM CFD software.
By making indoor temperatures and airflow visible through calculation, we check at the design stage whether ventilation rates, the positions of supply and exhaust openings, and the way air is supplied are appropriate.
Even for large spaces and rooms with high heat loads, which are hard to judge from drawings and calculation sheets alone, we can propose designs backed by evidence.
Features of our analysis system
- 1In-house analysis system built on OpenFOAM
We model rooms from architectural drawings (DXF, IFC) and handle everything in-house, from meshing and computation to visualizing the results.
- 2Steady-state to transient analysis
Steady-state analysis shows the overall trends; for large spaces where airflow fluctuates over time, we run transient analysis with parallel computing on Ubuntu (Linux) and evaluate time-averaged results.
- 3Thermal airflow analysis with buoyancy
We solve equipment heat and ventilation together to find vertical temperature differences, where hot air accumulates, and the temperature at working height.
- 4Verification by heat balance
We compare the results with a heat balance based on ventilation rates and heat loads, and report only after confirming that the conditions were set correctly.
Software: OpenFOAM (open source) / Ubuntu (Linux)
Analysis workflow
- STEP 1Modeling
We model the room, supply and exhaust openings and equipment from the architectural drawings.
- STEP 2Setting conditions
We set ventilation rates, air supply, heat loads and outdoor conditions.
- STEP 3Computation
Steady-state analysis shows the trends; transient analysis follows where needed.
- STEP 4Evaluation and proposals
We evaluate with temperature and velocity sections and height-by-height summaries, and put together improvement proposals.
Main applications
- Ventilation of large spaces with high heat loads, such as factories and plant rooms
- Heat removal from mechanical and electrical rooms
- Air supply and thermal environment in offices, meeting rooms and halls
- Ventilation of kitchens and workrooms, and the spread of odors and contaminants
What the analysis shows
- Temperature distribution at working height and vertical temperature differences
- Where hot air accumulates or air stagnates
- Heights at which heat-sensitive equipment such as control panels can be installed
- Whether ventilation rates and the number and layout of fans are sufficient
- Whether measures such as mixing fans are effective
Case study
Ventilation study for a large space with high heat loads
In a plant room with a large atrium and high-heat equipment, we used transient analysis to check whether the planned ventilation rate would keep the working zone within the temperature limit, and on which floors control panels could be installed.
We also compared adding mixing fans and found that they would pull hot air from the upper part down into the working zone, making things worse. We confirmed that the planned ventilation rate alone was sufficient.
Artificial Intelligence
We are linking AI with BIM to automate work from drafting to calculation reports.
In addition to Rebro, our main CAD for building services design, we have introduced Revit.
We connect AI and Revit through MCP (a common protocol for connecting AI with software) and are building an environment where instructions to AI produce drawings in Revit and extract information from them.
By automating the flow of data from drawings to calculation reports, we aim to prevent transcription errors and shorten working time.
Software: Rebro (NYK Systems) / Revit (Autodesk)
AI
MCP
Revit
- Drafting
- Room data extraction
- Calculation reports
- Equipment selection
Automating the process from room polygons to equipment selection
- STEP 1Automatic room polygons
We automatically draw the extent of each room (room polygons) from the architectural drawings. About 80% of this step is now automated.
- STEP 2Room data extraction
Room names, floor areas, ceiling heights, volumes and the areas of exterior and interior walls are extracted from the drawings into an Excel sheet.
- STEP 3AI-assisted ventilation calculations
Ventilation calculation reports are developed from the room property data.
- STEP 4Load calculation input
Information needed for HVAC load calculations, such as the area and orientation of walls and windows, is taken off.
- STEP 5HVAC load calculations
Input data for the load calculation software is prepared and the calculation is run.
- STEP 6Automatic equipment selection
Ventilation and HVAC equipment is selected from the results of the ventilation and load calculations.
Automatic 3D Revit models from 2D architectural drawings
From 2D information such as architectural and structural floor plans and grid lines, we automatically build 3D models in Revit.
We use them to check clashes with building services and to study supports for piping and ductwork, and they make meetings with everyone involved easier to follow.
Examples of how we have used AI
- Taking off room areas, wall lengths and orientations from architectural drawings (DXF) to prepare HVAC load calculation input
- Automatically preparing import sheets for APAK-MECH, the HVAC load calculation software specified by Japan's Ministry of Land, Infrastructure, Transport and Tourism
- Design assistance from general architectural drawings to ventilation and HVAC calculation reports, equipment schedules and zoning drawings
- Revising ventilation calculation reports to follow changes in architectural drawings (with changes shown in red)
- Preparing heat load conditions for room data sheets from heat load calculation reports
- Converting tables in CAD drawings into Excel, and linking Excel tables back to the drawings (saving updates the drawing)
- Extracting duct routes from Rebro IFC data to automate static pressure calculations
- Reading piping networks from piping drawings to size refrigerant pipes
- Determining whether safety measures are needed in case of refrigerant (R32) leaks
- Checking construction cost estimates against design quantities
- Setting conditions, running computations and visualizing results for OpenFOAM airflow analysis
Every drawing and calculation report prepared with AI is checked by our building services engineers before it is delivered.