Top 10 HVAC Interview Questions & Answers

In this video you will see the top 10 HVAC interview questions and answers that will definitely asked by the interviewer. Enhance your HVAC technical skills after learn these questions.  

To learn more questions and answers visit http://www.sofcontraining.com/hvac-design-and-drafting.htm

HVAC industry in need of skilled manpower

Currently India's HVAC industry is Rs. 25000 crore and is growing continuously at a constant pace.

The development has started which will upgrade the utilities. Due to this fact, there is a need to improve the systems covering air-conditioning & ventilation, fire & safety and plumbing. It requires a higher level of engineering and co-ordination between. We have to be ready for the future now by training the fresh engineering pass out students and up-skilling those who are already in this industry but unaware of the huge potential and requirement of the appropriate skills required.

The engineers get themselves prepared by getting hands-on training in Heating, Ventilation and Air Conditioning: Design and Drafting where you should learn about the following: 

• Fundamentals of HVAC 
• Modes of Heat Transfer, Sensible Heat and Latent Heat
• Basic Refrigeration System or Vapor Compression Cycle
• Pressure – Enthalpy Chart
• Accessories used in the SystemRefrigerant and Brines
• Function & Types of Compressor, Condenser, Expansion Valve, EvaporatorWindow A/C
• Working of Window A/C, Split A/C, Types of Split A/C, Working of Split A/C with Line Diagrams,
• Direct Refrigerant system, Dry Bulb Temperature, Wet Bulb Temperature
• Dew Point Temperature, Relative Humidity, Humidity Ratio
• Cooling Load Steps, Wall, Glass, Roof, Partition, Load Calculations (Manually using E-20 form)
• ESHF, ADP & Air Flow Rate (CFM) Calculation
• Duct-Definition & Terminology, Consideration, Duct sizing methods
• Duct sizing as per Aspect Ratio, Finding Duct size using Ductulator
• Gauge selection for Sheet Metal
• Legends and Symbols
• Selection of Diffusers and Grilles, Duct Materials and Insulation materials used in HVAC Industry
• Drawing @ Duct supports, @ CHW Pipe supports
• Concept of CAV & VAV
• Selection of Motor HP
• Selection Fan/Blower RPM
• Function of Valves
• Openings for CHW Pipes passing through Wall
• Selection of Pump and Head Calculation, XL sheet for Load Calculations
• Duct sizer for Duct sizing, Psychrometry Software

 

Energy Conservation Measure (ECM) Strategies in HVAC Control System for Green Buildings

Any building which is designed so that there is an optimization in the consumption of energy is known as Green Building or Intelligent Building. In other words, Green Building is one that achieves high performance over the full half cycle in the following areas:

• Minimal consumption of energy – due to reduction of need and more efficient utilization of nonrenewableenergy resources.
• Minimal hazardous emissions in the atmosphere having negative environmental impacts, especially thoserelated to greenhouse gases (GHG), global warming.
• Maximum quality of comfort of human beings in the context of heating, cooling and ventilation, acoustics/noise, and visual aspects.

The following strategies should be adopted after considering life cycle cost analysis of ECM strategies to save energy in HVAC Control Systems.

• Demand Control Ventilation (DCV) using CO2 Sensors
• Dedicated Outdoor Air Systems
• Air to Air Heat Recovery System
• Consider Variable Speed Drives for Pumps, Fans & Compressors
• Chilled Beams
• Night Pre Cooling
• Thermal Storage System for Cooling
• Displacement Ventilation
• Gas Fired Chillers
• Control Cooling Tower Fans by Sensing Ambient Wet Bulb Temperature 

For more information Kindly contact Ms. Usha Nishad @ Sofcon Group, 9873630785

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HVAC Industry: SWOT Analysis

STRENGTHS:

·         Generally, the consumers across the world regard HVAC as a 'must-have' in most segments in the global markets. It has direct relation in improving the productivity of the users and profitability of commercial sectors. Therefore, HVAC is one of the CORE industry globally.

·         The importance of HVAC to some important business sectors:-

                      I.        IT Sector

                    II.        Telecom Sector

                   III.        Hospital Sector

                  IV.        Food Industry

                   V.        Real Estate & Infrastructure

WEEKNESS:

·         Almost 70% of the building energy cost can be attributed to AC system.

(Infact, this creates an opportunity in a new sector i.e. HVAC control closely related with Building Automation- HVAC Control, Fire Detection and Alarm System, Access Control System and CCTV Surveillance System, Public Address System, Gas Suppression System)

·         Initially a huge investment of around 20% of the cost of the building in HVAC equipment

·         Skilled man-power in HVAC Design and Drafting is scarced.

·         Un-balanced demand due to different geographical locations for eg. Major focus on Refrigeration/ AC in countries like India, whereas focus on Heating in economies like Canada

·         Generally organizations consider AC and Heating as LUXURY

OPPORTUNITY:

·         Global HVAC industry is expected to grow consistently at the rate of 5 ~ 6% annually for the next 05 years

·         In all major regions of the world, the industry is yet to be matured and therefore there is a huge demand of HVAC equipment.

·         The present growth rate has a potential to match the growth of global IT industry

·         The current scenario will lead to the development of more Energy efficient HVAC equipment, globally

·         New opportunities are emerging due to concepts like Green Building, Carbon Credits, Energy Recovery, Building Management System, District Cooling etc

·         Convergence of various disciplines like Mechanical, Electrical, Architecture, Civil, Electronics, IT and Instrumentation, leading to new & exciting careers

THREATS:

·         Use of Chloro Fluro Carbons (CFC) as refrigerants has now resulted in an Ozone hole thereby threatening the environment

·         Growth is directly related to sectors like Real Estate development

·         Global Warming & Pollution through excess carbon release are some of the other aftermaths

·         Soaring Energy cost can bring in uncertainness in the growth pattern

·         Man power shortages on account of Multi-disciplined job requirements in HVAC industry

For more information Kindly contact Ms. Usha Nishad @ Sofcon Group, 9873630785

Calculating duct size in HVAC Design and drafting

HVAC Designing and drafting is going to be one of the fastest growing industry segment. We are the fastest developing economy in the world, whole world is eyeing India and its huge market. A slight growth in our GDP number will bring a huge push to our infrastructure sector. Infrastructure sector whether its in commericial space, smart building, green buildings, HVAC System and HVAC Designing and drafting is going to play big role. While discussing HVAC, its important to explain the importance of duct sizing. When we calculate the duct size as part of HVAC designing and drafting, then some the methods used for this are:

· Velocity reduction method

· Equal friction method

· Static regain method

Aspect ratio is a very important aspect in the process of duct size calculation in air conditioning. It is the ration of width is to height and this ration must be less than or equal to 4:1. Meaning that if width of the duct is 4 feet then height must be less than or equal to 1 feet and vice versa.

This is to maintain a uniform airflow and avoid turbulence of air flowing inside the HVAC duct.

Although the best aspect ratio is 1:1 or 1:2 but it is maintained according to the HVAC site condition. HVAC duct designing is done in the following aspects in particular:

· CFM (Cubic feet per minute)

· Friction loss (to be maintained < 0.1 feet/100 feet of straight duct

· Velocity in fpm for main branch, sub branch, coil velocity and air terminal or grille velocity

· Aspect Ratio

· Plenum height or distance between false ceiling and base of slab; leaving 3 to 4 inches from the top of duct and bottom of duct for insulation, fittings and supports or any services like cable tray passing over the duct.

The broad objective of HVAC designing and drafting is to maintain distributed and uniform airflow at all times. 

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Technification of HVAC Industry

This article is about rapid technification of HVAC industry/ HVAC Design and Drafting industry. A growth of 15 to 20 percent is envisioned which will offer excellent potential for years to come. Air conditioning and refrigeration industry have undergone significant changes in the last 02 decades. There have been changes in HVAC technology, change in customer expectations and change in skill sets required for HVAC Design and drafting, as well as opportunities offered for growth.

Advancement in technology of hardware such as compressors, heat exchangers, blower systems, heat recovery units have indeed been very significant. However areas where change has impacted the maximum is in controls and control systems. If at one time the competence of the technician was judged by the weight and variety of his tool box, today’s technician may come up with just a laptop for diagnosis. Or he may even sit at a remote location and monitor the equipment at your premises.

Control and monitoring systems which were electromechanical or pneumatic at one time have been replaced by DDC direct digital controls. Which predict derivative functions on hw the system is going to perform in a given situation and initiate corrective action. Intelligent buildings are an outcome of these developments.

The need for skilled manpower

This has resulted in a major change in the skill sets require at all levels in specially HVAC Design and drafting functions of HVAC industry. The biggest challenge the industry is facing today is the lack of skilled manpower. We at Sofcon India Pvt Ltd are committed to bridge this gap. Our HVAC training courses are: HVAC Design and drafting, HVAC Control, Psychrometric charts, Heat load calculation, duct designing, hydronic systm, Air handling units, fire life cycle, fire alarm systems, HVAC Control system, Building automation system, CCTV Surveillance and access control system. Training programs consist of more hands-on practical exposure & training by professionals involved in HVAC Designing, project, erection and commissioning

Both in respect of technicians as well as engineering graduates, the entry level candidates are not attracted by this industry. Having been part of this industry for quite a long time, we can say with confidence that with a cumulative annual growth potential of 15 to 20% this industry will continue to offere attractive opportunities for years to come.

ISHRAE (The Indian Society of Heating, Refrigerating and Air Conditioning Engineers) works with 60000 students across 150+ student chapters across the country. The job junction program organised by ISHRAE time to time helps bring together meritorious students and prospective employers.

For more, visit at www.sofcontraining.com

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Bhopal +91-9755559168
Vadodara +91-9898666980
Ahmedabad +91-9227185900
Pune +91-7387700416

HVAC Design and Drafting in a data centre

It is important to understand basic concept of server in order to under data server and server rooms initially and later get into the understanding, requirements and also the equipments present in the data centre as most of the equipment load influences the HVAC design and drafting loads.

Server: can defined as CPU of larger capacity i.e. storage memory, operating speed, operating options and possibility of networking.

Server room: companies or firms maintain servers for the purpose of their database and operating of their local networks they require a room for this purpose it’s maintained in a room.

Data centres: these originated from the concept of server rooms but these are at a larger scale different firms place their servers at single place. Which is managed by single management on the basis of certain fee charged per server.

Basic requirements for data centres:

• Power
• UPS
• Air-conditions
• Generator backup.
• The data centres require a 24 hours air conditioning for sustaining the facility.
• Different types of HVAC units used for data centres are:
• Direct expansion air cooled units
• Direct expansion water cooled units
• Dual fluid unit.

The system used for the HVAC design and drafting of server room and also preferable system is DX system UFAD type as the ducts and the other components are distributed under the floor but how ever this system requires special structural stability.

Expected features of an HVAC system in a data centre:

• the system should have high CFM per ton
• high sensible heat ratio
• It should be suitable for 24 hour and 365 day operation.
• It should have in built options of heater, humidifier, dehumidifier to control temperature.

Process of selecting right capacity HVAC System for server rooms:

The following points are to be considered and taken in to account while making equipment selection:

• The inside conditions of temperature and humidity recommended by server manufacturers is 22 degree and 50 % RH
• Suitable derating of equipment capacity must be considered based upon condensing temperature which is 11 degree higher than the ambient temperature and varies with ambient temperature.
• Equipment selection must satisfy the heat load and air quantity requirements heat loads should account for the following internal loads:
• Occupancy levels are minimum normally 2-3 persons
• Lighting loads are normally considered at 1.5 watts per sq.ft
• Diversity factor for equipment load is 60-80%. 

 For more inquiries, Kindly contact:

http://www.sofcontraining.com/hvac-design-and-drafting.htm

or

Call Now Our TOLL FREE No. 1800 - 200 – 4051
Noida +91-9873630785
Delhi +91-9711861537
Gurgaon +91-9873588305
Lucknow +91-9838834288
Allahabad +91-7704003025
Jaipur +91-8058033551
Mohali +91-9873349806
Bhopal +91-9755559168
Vadodara +91-9898666980
Ahmedabad +91-9227185900
Pune +91-7387700416