Heating, cooling, ventilation and central plant engineering developed from verified load calculations through schematic design, detailed documentation and construction support.
HVAC design at SEINZEN begins with measured heating and cooling loads derived from building geometry, envelope performance, internal gains and occupancy profiles. System selection follows load characteristics, spatial constraints and operational requirements rather than template-based equipment schedules.
Central plant, air handling units, fan coil systems, variable air volume distribution and dedicated outdoor air strategies are developed to maintain indoor air quality, thermal comfort and energy performance across normal and part-load conditions. Smoke control and stair pressurisation interfaces are coordinated with fire engineering from schematic stage.
Design documentation is prepared in Revit MEP production models with calculation reports, equipment schedules and schematic drawings issued at defined milestones. Ductwork pressure classes, pipework sizing and control sequences are defined to support tender, installation and commissioning.
Construction-phase support includes shop drawing review, model revision tracking and coordination with electrical, plumbing and fire protection disciplines to maintain design intent through installation and testing.
Dynamic and steady-state load calculations using recognised methods, accounting for solar gain, infiltration, occupancy diversity and equipment schedules.
Chiller, boiler, cooling tower and heat pump plant sized with redundancy, part-load efficiency and maintenance access considered from concept stage.
AHU, FCU, VAV and DOAS layouts with duct sizing, pressure loss analysis and acoustic attenuation for occupied and sensitive spaces.
Outdoor air rates, filtration grades and demand-controlled ventilation aligned to ASHRAE 62.1, EN 16798 or project-specific criteria.
Stair, lobby and atrium smoke management strategies coordinated with fire protection and architectural compartmentation.
Chilled water, heating water and condenser water networks with pump selection, expansion provision and control valve authority.
Performance specifications, duty schedules and selection criteria for major plant and terminal units prepared for tender evaluation.
System strategies assessed against energy targets, heat recovery opportunities and renewable interface requirements before design freeze.
Shop drawing review, TAB procedure input and functional performance criteria defined to support verified handover.
Project requirements, climate data, envelope assumptions and spatial constraints reviewed to establish basis of design and system options.
Heating, cooling and ventilation loads calculated per zone; centralised, decentralised and hybrid strategies appraised against brief and budget.
System diagrams, plant layouts and riser strategies issued for design team review with preliminary equipment selections and energy assumptions.
Revit production models, duct and pipe sizing, control schematics and equipment schedules prepared to construction documentation standard.
Federated model coordination, clash resolution and drawing issue with calculation reports and specifications for tender.
Submittal review, RFI response, site inspection and model updates through installation, TAB and commissioning phases.
Peak and part-load calculations using transfer function, radiant time series or dynamic simulation inputs depending on project complexity and certification requirements.
Coil selection, dehumidification, reheat strategies and outdoor air preconditioning defined to maintain space conditions across seasonal variation.
Equal friction and static regain methods applied with SMACNA pressure class selection, leakage limits and acoustic criteria for occupied spaces.
Chilled and heating water networks sized for velocity limits, pressure drop, diversity and minimum flow requirements at terminal units.
Air distribution patterns, throw distances and mixing effectiveness assessed for deep-plan offices, atria and healthcare pressure-regime spaces.
Operating modes, setpoint schedules, economiser logic and fault alarms defined for integration with building management systems.
NC and NR targets applied to AHU selection, duct attenuation and terminal device specification for noise-sensitive occupancies.
Zone boundaries aligned to solar exposure, occupancy and internal gains with diversity factors applied to central plant sizing.
Containment strategies, redundancy levels and thermal guidelines aligned to ASHRAE TC 9.9 and Tier requirements where applicable.
Pressure cascades, isolation room airflow, operating theatre conditions and medical gas coordination per ASHRAE 170 and NFPA 99.
Q = m × cp × ΔT
Q = sensible heat rate (W); m = mass flow rate (kg/s); cp = specific heat (J/kg·K); ΔT = temperature difference (K)
Sensible heating and cooling load verification for air and water systems at design and part-load conditions.
Apply fluid properties at mean temperature; account for safety factors per project basis of design.
Q = U × A × CLTD
Q = transmission heat gain/loss (W); U = overall heat transfer coefficient (W/m²·K); A = surface area (m²); CLTD = cooling load temperature difference (K)
Envelope transmission component of cooling and heating load calculations for external building elements.
CLTD or equivalent methods selected per applicable standard edition and climate zone.
ΔP = f × (L/D) × (ρv²/2)
ΔP = pressure drop (Pa); f = friction factor; L = duct length (m); D = hydraulic diameter (m); ρ = air density (kg/m³); v = velocity (m/s)
Ductwork friction loss estimation for fan selection and static pressure budgeting.
Include fitting losses separately; verify against manufacturer data for final selections.
V̇ = Q / (ρ × cp × ΔT)
V̇ = volumetric flow rate (m³/s); Q = heat transfer rate (W); ρ = fluid density (kg/m³); cp = specific heat (J/kg·K); ΔT = temperature difference (K)
Hydronic flow rate determination for chilled and heating water circuits serving coils and heat exchangers.
Select ΔT to balance pump energy, pipe sizing and control stability.
ACH = (Q × 3600) / V
ACH = air changes per hour; Q = supply airflow (m³/s); V = room volume (m³)
Ventilation rate verification against code minimums and project-specific indoor air quality targets.
Distinguish between supply, extract and outdoor air rates per applicable ventilation standard.
Final design values must be determined using project-specific inputs, applicable standards, manufacturer data and engineering judgement.
HVAC systems are modelled in Revit MEP at defined LOD milestones with equipment, ductwork, pipework and insulation represented to support coordination, quantity extraction and construction issue.
Shared parameters carry design data including flow rates, pressure classes, equipment tags and system classifications for schedule generation and federated model exchange via IFC where required.
Navisworks clash detection sessions integrate architectural, structural and MEP models with responsibility matrices documenting resolution of hard and soft clashes before construction issue.
Model revisions are tracked through documented issue cycles with calculation reports and schematic drawings cross-referenced to model element IDs for traceability through tender and construction.
ASHRAE 62.1
Ventilation for Acceptable Indoor Air Quality
Commercial and institutional ventilation design
Minimum outdoor air rates, ventilation effectiveness and demand-controlled ventilation requirements.
ASHRAE 90.1
Energy Standard for Buildings Except Low-Rise Residential
Energy-efficient HVAC system design
Equipment efficiency minimums, economiser requirements and system controls for compliance modelling.
ASHRAE 170
Ventilation of Health Care Facilities
Hospital and healthcare HVAC
Operating theatre, isolation room and patient care area ventilation and pressure requirements.
ASHRAE Handbook — Fundamentals
Fundamentals Volume
Load calculation and psychrometrics
Reference methods for heat transfer, psychrometric processes and load calculation procedures.
EN 16798-1
Indoor Environmental Input Parameters
European indoor environmental design
Thermal comfort, indoor air quality and ventilation criteria for non-residential buildings.
EN 12831
Heating Systems in Buildings — Method for Calculation of Design Heat Load
Heating load calculation
Design heat load methodology for European projects and cross-border reference.
SMACNA HVAC Duct Construction Standards
HVAC Duct Construction Standards
Ductwork fabrication and installation
Pressure class definitions, sheet metal gauges and joint requirements for duct systems.
NFPA 92
Standard for Smoke Control Systems
Smoke management engineering
Stair pressurisation, atrium smoke control and system performance criteria.
CIBSE Guide A
Environmental Design
UK and international building services
Internal design conditions, load estimation and system design guidance.
Eurovent Certified Performance
AHU and Fan Certification
Equipment specification
Verified performance data for air handling units, fans and heat recovery devices.
CTI STD-201
Cooling Tower Performance Certification
Central plant cooling towers
Thermal performance verification and specification criteria for cooling tower selection.
VDI 6022
Hygiene Requirements for HVAC Systems
Hygiene-sensitive installations
Duct and AHU hygiene requirements for healthcare, food processing and clean environments.
| Code | Standard | Application area | Project relevance |
|---|---|---|---|
| ASHRAE 62.1 | Ventilation for Acceptable Indoor Air Quality | Commercial and institutional ventilation design | Minimum outdoor air rates, ventilation effectiveness and demand-controlled ventilation requirements. |
| ASHRAE 90.1 | Energy Standard for Buildings Except Low-Rise Residential | Energy-efficient HVAC system design | Equipment efficiency minimums, economiser requirements and system controls for compliance modelling. |
| ASHRAE 170 | Ventilation of Health Care Facilities | Hospital and healthcare HVAC | Operating theatre, isolation room and patient care area ventilation and pressure requirements. |
| ASHRAE Handbook — Fundamentals | Fundamentals Volume | Load calculation and psychrometrics | Reference methods for heat transfer, psychrometric processes and load calculation procedures. |
| EN 16798-1 | Indoor Environmental Input Parameters | European indoor environmental design | Thermal comfort, indoor air quality and ventilation criteria for non-residential buildings. |
| EN 12831 | Heating Systems in Buildings — Method for Calculation of Design Heat Load | Heating load calculation | Design heat load methodology for European projects and cross-border reference. |
| SMACNA HVAC Duct Construction Standards | HVAC Duct Construction Standards | Ductwork fabrication and installation | Pressure class definitions, sheet metal gauges and joint requirements for duct systems. |
| NFPA 92 | Standard for Smoke Control Systems | Smoke management engineering | Stair pressurisation, atrium smoke control and system performance criteria. |
| CIBSE Guide A | Environmental Design | UK and international building services | Internal design conditions, load estimation and system design guidance. |
| Eurovent Certified Performance | AHU and Fan Certification | Equipment specification | Verified performance data for air handling units, fans and heat recovery devices. |
| CTI STD-201 | Cooling Tower Performance Certification | Central plant cooling towers | Thermal performance verification and specification criteria for cooling tower selection. |
| VDI 6022 | Hygiene Requirements for HVAC Systems | Hygiene-sensitive installations | Duct and AHU hygiene requirements for healthcare, food processing and clean environments. |
Applicable standards depend on the project location, building use, authority having jurisdiction, employer requirements and contract documents. The current adopted edition must be confirmed at the beginning of each project.
Design criteria, assumptions, system strategy and applicable standards documented for client and design team agreement.
Zone-level load summaries with input data, methodology and results traceable to model geometry and envelope data.
System diagrams, plant room layouts and riser schematics showing major equipment and distribution routes.
Coordinated HVAC models at defined LOD with equipment, ductwork, pipework and insulation represented.
AHU, chiller, boiler, pump, FCU and terminal unit schedules with duty, electrical data and control requirements.
Pressure loss analysis, sizing tables and velocity verification for major distribution networks.
System operating modes, control points and BMS integration requirements for major HVAC plant.
Technical specifications for major equipment and installation prepared for tender issue.
Navisworks clash detection results and resolution records issued before construction documentation.
Pressurisation and smoke management design basis where required by fire strategy and applicable codes.
Design flow rates, setpoints and acceptance criteria provided for testing and balancing procedures.
Asset tagging, maintenance access and handover documentation requirements for operational continuity.
Load calculations independently reviewed against input data and envelope assumptions before schematic issue.
Equipment selections verified against manufacturer performance data at design and part-load conditions.
Model geometry and system routing checked through federated clash detection before construction issue.
Drawing and schedule cross-referencing validated to ensure tag consistency between models and documentation.
Design criteria and control sequences reviewed against applicable standards and project-specific requirements.
Submittal review documented with deviation tracking through to installation verification.
Commercial office towers and deep-plan workplaces requiring efficient central plant and zone-level comfort control.
Healthcare facilities with pressure-regime HVAC, isolation rooms and operating theatre ventilation to ASHRAE 170.
Hotels and hospitality projects with guest room systems, kitchen extract and pool dehumidification requirements.
Data centres and mission-critical facilities with redundancy, containment and thermal resilience design.
Mixed-use developments integrating retail, residential and office loads with shared plant optimisation.
Industrial and laboratory facilities with process ventilation, fume extract and cleanroom classification support.
Dynamic simulation is recommended for buildings with complex glazing, significant thermal mass, mixed-mode ventilation or certification targets requiring hourly analysis. Steady-state methods remain appropriate for many conventional commercial buildings where ASHRAE or CIBSE simplified methods provide adequate accuracy.
Smoke control requirements are established with the fire engineer at schematic stage. Stair pressurisation, atrium exhaust and fire damper locations are integrated into duct routing and fan selection with cause-and-effect matrices coordinated across disciplines before detailed design issue.
Models typically include equipment, ductwork, pipework, insulation and hangers at LOD 300–350 depending on project BIM execution plan requirements. Shared parameters carry design data for schedule generation and quantity extraction.
Yes. Existing condition surveys, measured load assessments and phased installation strategies are developed for retrofit projects, including temporary provisions and occupied-building constraints.
System options are appraised against project energy benchmarks and certification requirements during concept and schematic stages. Heat recovery, free cooling and high-efficiency plant selections are evaluated through lifecycle cost comparison before design freeze.
Contact our mechanical engineering team to review project requirements, load analysis approach or central plant strategy for your building.