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  • Writer's pictureArvind Dang

Design of Robust air-conditioning works for any building.



This article covers the following aspects.

1. Unique Characteristics of a Robust Airconditioning Design Works

2. Common design aspects of Robust air- conditioning works

3. Listing of critical specifications-BOQ Materials wise, that contribute to making air-conditioning designs  robust

4. Listing of  installation activities in Air conditioning works wherein need  to incorporate good design practices

5.  Listing of 8 stages for designing  air-conditioning works  

6, Listing of activities (including unethical) that can adversely impact business during each design stage of air conditioning

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

1. Characteristics of a Robust Airconditioning Design Works

  • Optimum usage of energy-saving BOQ materials and systems for air conditioning (e.g., chillers, VRV, outdoor units/indoor units, low power consumption units, etc.)

  • BOQ, refringent and the entire Air-conditioning system that conforms to local Quality standards and preferably international quality standards such as ASHRAE (American Society of Heating, refrigeration & air-conditioning)

  • Layout schemes, coils that are optimum and are concealed  

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

  • Configuring the design of air-conditioning BOQ, their installation, and commissioning that ensure conformance of integrated system to meet statutory requirements 

  • Integrated building management systems

2 Aspects which are common with other HVAC and MEP design package like including air- conditioning system, basement ventilation etc  

Design schemes that enable the installation & commissioning of equipment with optimized capacity

  • Design arrangements that will allow 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  

  •  Proposing the right choice of BOQ  materials in specifications.

  • Optimizing costs  

 3 Listing of critical specifications-BOQ Materials wise, that contribute to making air-conditioning designs  robust

Types of materials for use

Description of specifications


Make/Brand, Tonnage, Inverter Technology, star rating, refrigerant, Chiller’s -British thermal units /hour or a ton of refrigeration /hour

Outdoor and Indoor units

Size, make,/brand  colour, filter type/size,


Cfm (cubic feet per minute and horsepower

condenser coils

Tube material, tube diameter, thickness, temperature, vapor density, environment friendliness

Instrumentation, and remote controls

Pressures and temperatures ranges


Freezing temperature, evaporation pressure, condensation pressure, environment protection  requirements

and so on


4. Listing of  installation activities in Air conditioning works wherein need  to incorporate good design practices

  • 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

  • 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 air-conditioning  design process using designing software:

Essential technical steps/activities include performing the following for evolving

Design calculations for determining capacity for the Airconditioning works for the project include:


  • ·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 Air-conditioning) and National Building Code, BIS, National Building Code, etc. 

  • Including detailed 3D BIM Modelling Services with air conditioning  with BOQ depicted,

  • ·Develop air-conditioning works related to shop drawings

  • ·Designs supporting all applicable quality standards

  • Software like Revit MEP, AutoCAD HVACQuick Allot, or similar ones having 3D MEP BIM modelling features can be considered for designing air-conditioning works.


5. Listing of Eight stages for developing the design of Air-conditioning works

Design activities vary considerably from company to company, but generally, there are eight stages to designing the MEP-air-conditioning 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 process

  • 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

My book gives More design stage details as per the link below.

Book 1

Amazon link: India-

Amazon link-Global-

Eight Design Stages  

Stage 1)

  • Develop a preliminary design brief and drawings -Performing the below activities

  • ·Developing Strategic plans for design  aligned with visions

  • Developing comprehensive design brief (vis a vis cooling  load or and heating load etc.)

  • Developing all preliminary designs  

Stage 2) Detailed design /drawings /specifications and scheme- Performing the below activities


  • Making comprehensive designs for air conditioning works on essential aspects such as those below.

    • i)Design features vis a vis Chillers, VRV, Outdoor units, Indoor units, air conditioning, pipes, insulations, etc

    •  ii) National and international standards for quality    

    • iii) Specifications of   BOQ material

    • iv) Tolerances on quality of artistry vis a vis installation and commissioning

  • Incorporating comprehensive Quality requirements

  • Considering comprehensive Design-related construction processes for air-conditioning works

  • Design by considering standardization leads to lower  costs

  • Accurate Bill of quantities for each design area /no off of air-conditioning works package items     

  • Factoring appropriate acceptance criteria for air-conditioning works- design work in process and completed area

  • Using licensed software while developing air-conditioning designs. *  

  • ·Issuing of design and drawings to air-conditioning works  contractor at project site with version control

Stage 3) Develop schematic drawings for statutory approvals and Incorporating all requirements vis a vis Statutory approval and design/drawings*


Stage 4) Develop tender with BOQ and specifications- Performing the below activities


Making tenders that are  comprehensive vis-à-vis technical specifications

  • ·      Tenders include options for multiple brands of various BOQ materials

  • ·      Tender drawings incorporating applicable quality standards for all works.

  • ·      Incorporating comprehensive Inspection requirements w.r.t. air-conditioning works.

  • ·      Tender drawings incorporate applicable Statutory requirements vis-à-vis applicable National/International codes. *


·      Stage 5)

  • Making construction drawings duly coordinated (GFC)-Design and drawings for air-conditioning works performing the below activities.

  • ·Making construction drawings accurate by obtaining and incorporating inputs from other design functions into various design elements for air-conditioning or works.

  • Preparing coordinated drawings for each relevant air-conditioning or work by factoring inputs from the Architect team, Interior design team

(Stage 6)

  • Perform final Design calculations -Performing the below activities

  • ·Validating designs after proper incorporation of all proposed connected heat loads, façade glass specifications, air leakages, and air conditioning at different progressive loads or estimated occupancy of constructed areas or pro-rata over some time 

  • ·Considering appropriate factors of safety & proposed statutory approvals * 

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


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-Performing the below activities


·Estimating costs based on detailed working vis a vis each essential BOQ item (such as below)  and their quantities  


  • ·Chillers or VRV,

  • ·Outdoor units,

  • ·Indoor units,

  • · Valves

  • ·Cablings/wirings,

  • · Fittings,

  • ·Instrumentation,

  • · Remote controls,

  • Refrigerants,

  • Air filters,

  • ·Air conditioning pipes,

  • ·Drainage pipes insulations, etc

Stage 8) Issue “As-built drawing”-post-work completion and approval- Performing the below activities


  • ·Using appropriate software and making “As-built drawings” designs and drawings after verification of actual supply and installation of each BOQ material for air-conditioning works* 


6.Listing of activities (including unethical) that can adversely impact business

  • ·Strategic plans for design not aligned with visions and

  • Developing a non-comprehensive design brief

  • In the tenders, the designer or consultant Insists on names of specific brands /vendors of BOQ, such as heat exchangers, valves, pumps for the Heating system, chillers, Outdoor units, indoor units of Air conditioners, etc., in collusion with vendors' return for commission/kickback from such vendors./contractors  * 

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

  • ·Compromising specifications for developing samples of air-conditioning-related BOQ materials in collusion with vendor/contractor. *  

  • ·Using unlicensed software while developing air-conditioning-related designs. *  

  • Issuing of design and drawings to air-conditioning-contractor at project site without any version control

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

  • ·Bribing mandatory Agencies that approve the safety-related specifications (Human beings & environments) of air-conditioning design works relevant for safety, e.g., Choice of refrigerant, insulations, control panel, etc.* 

  • Contractors influence certifying agencies to compromise statutory certification in return for favors. *      

  • Making tenders where technical specifications are inadequate or are deliberately stated vaguely for subsequent manipulations amongst the designer and contractor with ulterior motives. *  * indicates activity having statutory or and unethical implications   

You can read more about the activities that can adversely impact business in Chapter 3 of my handbook ETHICS in the real estate and hospitality industry, Volume 1- Architectural, Interior Design, and MEP services. “


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