Design of HVAC works (heating, ventilation, and air conditioning works - Activities that can adversely impact business -

As shared in an earlier MEP Electrical works design   blog, there are many MEP Packages such as:

·       Design of Electrical - external and Internal works, Designing of Airconditioning -Works, Design of lighting works, Design of plumbing and water (hot and cold) supply works, Energy management works for green building, firefighting works, Designing of lifts/elevators works, Design of STP (sewerage treatment plant) works, Waste management works, Design of fuel storage and supply works, Design of solar energy works, Design of wind engineering works, Design of audio-visual works, Heating works, Ventilation & exhaust works, Acoustics works, Facility management works, Hospitality works like kitchen and laundry, IT infrastructure, Building automation, and so on

This blog covers the Design of Air conditioning & basement ventilation works  

This Design can be relevant for buildings used for residential, commercial, shopping malls, education institutes, hotels, hospitals, offices, etc.

Characteristics of a Robust Airconditioning and robust ventilation Design works can be measured vis a vis:

Robust Airconditioning

·       Optimum usage of energy-saving BOQ materials and systems for Air-conditioning (eg. Chillers, VRV, Outdoor units/indoor units, low power consumption units, etc.)

·       BOQ, refringent, and the entire Airconditioning system that conforms to local Quality standards and preferably international quality standards such as ASHRAE (American society of heating, refrigeration & Airconditioning)

·       Layout schemes designed for cold air supply distribution system, coils     that are optimum and are concealed  

·       Coming up with designs that are eco-friendly and sustainable energy

·       Configuring the Design of Airconditioning BOQ, their installation, and commissioning that ensure conformance of integrated system to meet statutory requirements 

·       Integrated building management systems

Robust Basement ventilation

·       Ability to extract and push out polluted air and introduce the same volume of fresh air at an hourly rate

·       Ability to condition the air to an acceptable usage level of quality that is comfortable

·       Meeting the statutory levels in terms of air quality levels (e.g. carbon mono oxide) within statutory levels.

·       Preferably meeting ASHRAE (American society of heating, refrigeration & Airconditioning) standards for the exchange of air in terms of cfm-cubic feet per hour with new or clean air.

·       Eliminating potential bacteria, microbes that cause respiratory issues or sinus problems 

Common aspects of a Robust air- conditioning and basement ventilation system

Design schemes that enable installation & commissioning of equipment with optimised capacity

·       Design arrangements that enable easy maintainability

·       Incorporate flexibility in the Design to meet challenges towards potential changes in technology or energy savings or costs  

·       Coming up with design solutions that are scalable /expandable

·       Approving specifications/brands of BOQ that enable the least downtime 

·       Approving designs that lay focus on the total cost of ownership including running costs

·       Delivering specifications and drawings that are easy to understand and incorporate international standards  

    Inputs that contribute to making an excellent Electrical design include:

1.      Proposing the right choice of strong materials, in terms of specifications while

       optimizing costs for:  

2 Incorporating, in HVAC-related Design & drawings, good practices for construction or & installation of the following as per applicable Quality standards:

i) Airconditioning

§  Installation of VRV or outdoor units, indoor units.

§  Central refrigeration plant, chillers

§  Distribution pipelines

§  Cooling towers

§  Air handling units

§  Grills, fans, filters &Fan coil units

§  Fabricating and laying of ducting, copper pipes,

§  Installing pipe insulations, control cables, v joints

§  Filling of refrigerants

§  Installation, testing, and commissioning of complete AC system

§  Installation of local cooling units

ii)basement ventilation

§  Fabrication of ducting & its installation

§  Installation of MS conduits, pressurization system, grills, diffusers, etc

§  Installation of fresh air fans, exhaust fans, propeller fans, air washers, pressure fans,

§  Installation of cable layouts and terminations, distribution panels

§  Installation, testing, and commissioning of the completed Basement Ventilation system

 iii)Providing inputs to the building architects,  Interior designers, and all other MEP-package designers for integration of all designs across the project  

3 Building quality in the MEP-HVAC design process-using designing software:

Essential technical steps/activities include performing the following for developing designs.

Design calculations for determining capacity for the Airconditioning & basement ventilation systems for the project include:

Air-conditioning  

·       Cooling load computation

·       Cool air distribution scheme

·       Incorporating installation, testing, and commissioning aspects and following local and international quality standards like ASHRAE (American Society for heating, refrigeration, and Airconditioning) and National building code, BIS, National building code, etc.

·       Including detailed 3D BIM Modelling Services with HVAC with BOQ depicted,

·       Develop airconditioning works related to shop drawings

·       Designs supporting all applicable quality standards

 ii) Basement ventilation

·       CFM and sizing calculations

·       Pressure loss calculations

·       Duct and diffuser layouts

·       Duct construction standards

Software like Revit MEP, AutoCAD HVAC, Quick Allot, or similar ones with 3D MEP BIM modeling features can be considered for developing design airconditioning and basement ventilation works.

Eight stages for developing the Design of Air-conditioning and basement ventilation

Design activities vary considerably from company to company, but generally, there are eight stages to designing the MEP-HVAC for buildings, as below. Whatever designing processes and software are used, designing must result in developing Robust designs by accomplishing the following:

·       Build designs that are comprehensive, accurate

·       Contributes to building quality in construction by incorporating national and international quality standards in BOQ/material specifications and construction processes

·       Integrates statutory and safety requirements (if applicable) in the designs and drawings  

·       Optimise project costs

·       Enables efficient delivery of designs & drawings

·       Incorporates maker-checker step in each design stage through the implementation   of segregation of duties concept

8 Stages are:

Stage 1) Develop a preliminary design brief and drawings

Stage 2) Detailed design /drawings /specifications and scheme

Stage 3) Develop schematic drawings for statutory approvals

Stage 4) Develop tender with BOQ and specifications

Stage 5) Making constructions drawings duly coordinated (GFC)-Design and drawings for HVAC works:

(Stage 6) Perform final Design calculations 

Stage 7) Making Cost estimates -For the entire project including in Rs and Cost/Sft. of the saleable area or built-up area or both

Stage 8) Issue “As-built drawing”-post-work completion and approval

This may require using software such as Quick Allot, Revit MEP, AutoCAD HVAC, and other software options.

In the below-listed activities, those marked *reflect those activities which can have adverse statutory implications.

Stage 1 Activities that can adversely impact business

·       Strategic plans for Design not aligned with visions

·       Developing non-comprehensive design brief (vis a vis cooling  load, air circulation requirements, etc.)

·       Skipping developing all preliminary designs  

Stage 2 Activities that can adversely impact business

·       Making Compromises in the airconditioning and basement ventilation designs by skipping or compromising on essential aspects such as below.

i)Design features vis a vis Heating works, Heat exchangers, Fan coil systems, Reverse cycle heating system, Distribution pipelines, Valves, Pumps, Fittings, Instrumentation and control, Local heating units, Chillers, VRV, Outdoor units, Indoor units, Centrifugal fans, jet fans, Ventilation, air conditioning, pipes, insulations, etc

                     ii) National and international standards for quality    

iii) Specifications of   BOQ material

         iv) Tolerances on workmanship vis a vis installation and commissioning

·       Not incorporating comprehensive Quality requirements

·       Not considering comprehensive Design-related construction processes for HVAC works

·       Design without considering standardization leading to higher costs

·       Inaccurate Bill of quantities for each design area /no off of HVAC package items     

·       Not factoring in acceptance criteria for HVAC design work in process and completed area

·       MEP designer or consultant Insisting on specific brands of BOQ such as heat exchangers, valves, pumps for the Heating system, centrifugal pumps, jet pumps for the ventilation system and chillers, Outdoor units, indoor units of Air conditioners, etc. in collusion with vendors of specific brands of BOQ items and getting financial favors. * 

·        

·       Assigning the same designer to develop designs, drawings schematic designs & drawings, who initially developed concept design thus not implementing the segregation of duties concept*

·       Compromising specifications for the development of samples of HVAC materials in collusion with vendor/contractor. *  

·       Using unlicensed software while developing HVAC designs. *  

·       Issuing of Design and drawings to HVAC contractor at project site without any version control

·       Not shredding waste designs/drawings or not deleting obsolete /old soft drawings*

Stage 3 Activities that can adversely impact business

·       Not incorporating all requirements vis a vis Statutory approval and design/drawings*

·       Bribing mandatory Agencies which approve the safety-related specifications of HVAC design works relevant for safety, e.g. fume extraction, insulations, etc*

·       Contractors influence certifying agencies for making compromising on certification in return for favours. *

·       Assigning the same designer to develop schematic designs and statutory drawings, who initially developed concept design or schematic designs thus not implementing the segregation of duties concept*

·        

Stage 4 Activities that can adversely impact business

·       Making tenders that are not comprehensive vis-à-vis technical specifications or are deliberately stated vaguely for subsequent manipulations amongst the MEP team members and contractor with ulterior motives. * 

·       In the tender, the MEP consultant/employees /engineers include names and brands of specific materials only for pre-identified /preferred vendors of the BOQ materials + MEP Engineer in return for commission/kickback from such vendors. *

·       MEP engineer recommends only a single source for many BOQ materials and thus leaving very few options with the project materials team to negotiate prices aggressively in return for commission /kickback to the MEP team from such vendors.

·       Tender drawings not incorporating applicable quality standards for all works.

·       Inspection requirements w.r.t. Airconditioning, basement ventilation works, etc., are not comprehensive.

·        

·       Tender drawings not incorporating applicable Statutory requirements vis-à-vis applicable National/International codes w.r.t safety. *

  Stage 5 Activities that can adversely impact business

·       Making constructions drawings inaccurate by not obtaining or not incorporating inputs from functions into various design elements for HVAC plans

·       Preparing coordinated drawings for each of relevant HVAC works scope items vis designs and drawings without factoring inputs from Architect team, Interior design team

·       Using unlicensed software while developing HVAC drawings

Stage 6 Activities that can adversely impact business

·       Validating designs without proper incorporation of all proposed connected heat load, air circulation, and air conditioning at different progressive loads or estimated occupancy of constructed areas or pro-rata over a period  

·       Considering the inaccurate proposed factor of safety & proposed statutory approvals * 

·       Inadequate vetting of design efficacy and drawings developed vis-à-vis specification of BOQ materials and installation requirements.

Stage 7 Activities that can adversely impact business

·       Estimating costs based on thumb rules rather than considering detailed working vis a vis each BOQ item and their quantities  

               Air-conditioning

Chillers or VRV, Outdoor units, Indoor units, Valves, Pumps, cablings/wirings, Fittings, Instrumentation, and remote controls, Refrigerants, air filters, air conditioning pipes, drainage pipes insulations, etc

Basement ventilation

 Centrifugal fans, jet fans, Ventilation, motors, cables, Ducting, Distribution pipelines, fittings, etc

·       Not considering installation, testing, and commissioning costs

Stage 8 Activities that can adversely impact business

·       Making “As-built drawings” designs and drawings without verification of actual supply and installation of each BOQ material for airconditioning works and basement ventilation works * 

You can read more about the 34 activities that can adversely impact business in Chapter 1 of my handbook ETHICS in the real estate and hospitality industry, Volume 1- Architectural, Interior design, and MEP services “