HVAC Engineer Interview Questions: How to Identify the Best Candidates

What is an HVAC Engineer Job Description?

HVAC engineers design and coordinate the installation of heating, ventilation, air conditioning, and commercial refrigeration systems.

HVAC engineers, sometimes referred to as mechanical engineers, possess proficiency in building codes, standards, and complex calculations for HVAC systems. Depending on the position, an HVAC engineer could oversee a team of HVAC technicians, perform preventive maintenance, or repair HVAC systems. HVAC engineers also typically possess superior problem-solving and communication skills, as they coordinate projects and communicate with customers.

Most online HVAC engineer job postings require previous work experience. Other HVAC engineer resume requirements include a bachelor's degree in mechanical engineering, a Professional Engineering (PE) license, experience with AutoCAD and Revit software, or other specialty experience. 

Related job titles within the HVAC engineering field could include HVAC design engineer, HVAC mechanical engineer, preconstruction and design engineer, mechanical project manager, or refrigeration engineer.

General Interview Questions

1. Why do you work as an HVAC engineer?

2. Why do you want to work for our company?

3. What are your career goals?

5. How would your references describe you?

HVAC engineer job interview questions allow employers to discover applicants' backgrounds, including their career goals and how they approach challenges on the job. The right questions can reveal whether an interviewee will be an ideal addition to your HVAC team.

HVAC or mechanical engineering companies should formulate an interview process to find the best engineering candidates. Managers at McWilliams & Son Heating and Air Conditioning in Texas follow a layered hiring process to ensure they place new hires in the right role. Follow a thorough vetting process before hiring, rather than discovering a newly hired employee isn't the best fit for your company.

1. Why do you work as an HVAC engineer?

Hiring managers who ask HVAC engineers why they work in HVAC ask the classic "Tell me about yourself" question. This gives engineers an opportunity to share why they have a passion for HVAC engineering, what they enjoy about their line of work, and how they want to continue their knowledge in the field. 

This is the time to ask about a candidate's overall HVAC knowledge, education, skill set, previous employers, licenses, and certifications, such as The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) Certified HVAC Designer.

2. Why do you want to work for our company?

Discover if engineering candidates understand your company and its core values. Candidates who research your company ahead of time show they know how to prepare and can express how their values align with your company's mission.

Ask about their expectations for the engineering job. What are their work schedule expectations? Are they comfortable working onsite? Do they have experience managing a team? Communicating from the start sets the right expectations for future success.

3. What are your career goals?

Ask about an applicant’s goals so you can understand what motivates them and what they aim to accomplish. Do they want to simply earn more money than their previous HVAC design job, or are they interested in a long-term career path, and learning more along the way? Depending on what your company can offer, either one may provide a great fit.

4. How would your references describe you?

HVAC engineers should know the areas where they excel. Get a list of references so you can learn how applicants performed at previous jobs, including information about their personality, interactions with co-workers, and how they addressed challenging HVAC design projects. 

Behavioral Interview Questions

1. How has your oversight prevented mistakes on projects?

2. How do you prioritize and delegate projects?

3. How have you handled interactions with an unhappy customer?

4. Here's a specific HVAC design challenge. What steps would you take to resolve this?

While many HVAC engineer interview questions focus on technical aptitude, HVAC companies should ask behavioral interview questions to determine how candidates approach work-related challenges.

Experienced hiring managers actively listen to a candidate's answer so they can follow up with additional, probing questions. It's important to focus on how a candidate answers, too—does a candidate directly answer the question, or do they provide a vague response? Do they choose to answer in a negative, blaming tone?

Even answers to seemingly off-hand questions can indicate the attitudes of your applicants, giving insight into how they view their work, approach problems, and interact with others.

Angie Snow, Director of Customer & Product Training at ServiceTitan and Vice President of Western Heating & Air in Utah, always asks one question to ascertain attitudes of candidates: “How’s your day going so far?” Candidates' values shine through in their answers, and the way they answer, she says.

1. How has your oversight prevented mistakes on projects?

Good HVAC engineers should know how to proactively minimize mistakes with oversight, communication, and a strong accountability process. Ask about what checks and balances they use to ensure projects follow proper technical specifications, and how they communicate with other team members. Determine how they detect mistakes, and what steps they take when mistakes do occur.

2. How do you prioritize and delegate projects?

When it comes to handling multiple, complex HVAC projects, the ability to prioritize and effectively manage time is a must. How does the candidate decide what aspects of a project to focus on first? How do they delegate tasks to subordinates? Knowing how to prioritize and reallocate work as needed is key to keeping projects on time and on budget.

3. How have you handled interactions with an unhappy customer?

If the HVAC engineering position requires customer interaction, asking about a difficult customer service experience shows the candidate's overall attitude about customers, as well as what steps they take to provide a positive customer experience. Whether it's explaining an HVAC system design problem or communicating a change in a project's timeline due to unforeseen supply issues, clear communication and the right attitude is of utmost importance.

4. Here's a specific HVAC design challenge. What steps would you take to resolve this?

Asking a question about an unknown HVAC design scenario gives HVAC engineering applicants the opportunity to demonstrate quick thinking and problem-solving skills. Their answers will indicate their critical thinking and breadth of knowledge.

Proper and efficient HVAC operations are essential. Knowing how to solve complex problems and effectively coordinating projects requires knowledge and excellent communication. 

Technical Knowledge Interview Questions

1. What was your most challenging project, and what did you learn from it?

2. What are the pros and cons of VAV and CAV systems?

3. What's the difference between sensible and latent heat loads?

4. How do you calculate heating and cooling loads?

5. What's your experience with sustainable HVAC solutions?

Since HVAC engineers work on complex and highly technical jobs, it's important a candidate possesses the right level of knowledge and technical skill.

Engineering candidates should possess comprehensive knowledge of heating and air conditioning systems, which includes selecting, sizing, and configuring air handling units (AHUs), fan coil units (FCUs), air-cooled or water-cooled chillers, and boilers. They must also thoroughly understand the refrigeration cycle and refrigerants.

HVAC design relies heavily on an understanding and analysis of psychrometric principles. Besides technical expertise, candidates should possess knowledge of HVAC standards and guidelines. Ask questions with technical aptitude in mind to narrow your list of eligible candidates.

1. What was your most challenging project, and what did you learn from it?

Ask candidates for an example of a challenging project to determine their level of expertise and the processes used to uncover solutions.

If confronted with an exceptionally complicated HVAC problem, engineers need to know when to reach out to other HVAC professionals for a solution. The ability to understand complex processes and learn from challenges is vital and determines the success of a project.

2. What are the pros and cons of VAV and CAV systems?

HVAC engineers must understand the benefits and drawbacks of a variable air volume (VAV) system versus a constant air volume (CAV) system to make the right decision for a project. Engineers need to take all factors into consideration when designing a system to most efficiently heat and cool buildings and effectively manage indoor air quality.

3. What's the difference between sensible and latent heat loads?

In the HVAC world, accurate application of energy principles results in comfortable building environments. Sensible heat refers to air temperature, while latent heat refers to moisture in the air. Calculations that include measuring airflow in cubic feet per minute (CFM) enable HVAC engineers to determine the correct size of an HVAC system.

4. How do you calculate heating and cooling loads?

Sizing HVAC units by heating and cooling loads requires following the proper methods. 

An HVAC load calculation shows the exact amount of BTUs (British thermal unit) a certain size of space requires for sufficient heating and cooling. By definition, a BTU is the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit.

Asking whether the candidate understands the Manual J residential calculation shows how much they know about the procedure, designed by the Air Conditioning Contractors of America.

5. What's your experience with sustainable HVAC solutions?

Modern customers want new, sustainable HVAC solutions that deliver benefits to the environment and their wallets. If your company provides services such as geothermal, solar power, or hydronics, ask about the candidate's knowledge of those systems, so you can continue to provide eco-friendly solutions to your customers.

Technology Interview Questions

1. How do you view mobile software in the HVAC industry?

2. What is your experience with using mobile technology on the job?

3. What tools do you use to explain problems and solutions to a customer?

Ask technology-related questions to see how much the candidate knows about HVAC trends and cloud-based software, such as ServiceTitan HVAC Software—used to streamline operations and enhance communication. Even if they don't possess past experience, a candidate's answer can help you determine if they see the value technology offers the HVAC industry, and their willingness to utilize it in day-to-day operations.

1. How do you view mobile software in the HVAC industry?

Engineers and project managers profit by using HVAC job costing software to accurately track project costs, integrating financial data from sold estimates, job invoices, purchase orders, payroll, and accounts receivable. These tools allow your HVAC employees to perform better as a team and complete projects more efficiently.

2. What is your experience with using mobile technology on the job?

Mobile technology allows an HVAC engineer or manager to easily view schedules, materials and labor costs, and other critical job information from anywhere. 

On the customer service side, team members can notify customers about the project in a timely manner. A seamless customer experience results in more return customers, and increased word-of-mouth referrals.

3. What tools do you use to explain a problem and solutions to a customer?

An HVAC project engineer or project manager may be the one to explain problems and solutions to customers, especially when it comes to big-ticket proposals. When employees confidently use HVAC software to present good-better-and-best proposals, it gives customers a clear picture of their options and benefits of each one. They may decide the "best" proposal saves them more money in the long run.

Payroll Interview Questions

1. What are your HVAC engineer salary expectations?

2. Have you ever worked for a company that uses performance-based pay?

3. What do you expect in terms of bonuses or sales program incentive funds (SPIFs)?

Online job postings show a demand for HVAC engineer jobs, from 154,800 to 588 jobs, depending on the online job search website and specific job title. Nationally, mechanical engineer jobs are forecast to rise by 12,400, or 4%, by 2029, according to the U.S. Bureau of Labor Statistics (BLS). 

The HVAC field remains competitive due to more workers retiring than entering the field, according to an organization seeking to close the skills gap. Put your company at the top of a candidate's list by offering competitive wages and benefits, as well as a positive company culture.

1. What are your salary expectations?

An HVAC mechanical engineer salary can range from $33,000 to $148,500 annually, with a national average of $82,752, according to ZipRecruiter. The average entry-level HVAC engineer salary is $72,420 annually.

Pay varies depending on a candidate's experience, duties, and geographic location. Find out the salary range for your state and offer appealing benefits to attract the best job candidates, and reduce turnover rates.

2. Have you ever worked for a company that uses performance-based pay?

If your HVAC company offers performance pay versus hourly rates, candidates need to understand your company's pay structure and how commission and bonuses affect the position. Using contractor timesheet software provides real-time timesheet tracking and customizable performance pay, so you can tailor your pay structures to obtain the best results.

3. What do you expect in terms of bonuses or SPIFs?

Ask about expectations for bonuses or other incentives. Communicate how your company values employee performance and demonstrate how top performance corresponds to increased pay.

Although it's not the only way to motivate, offering incentives makes the job more attractive to potential hires. Ask these and other questions to determine which HVAC engineering candidate best fits with your team, boosting your company's growth.