Mentoring HVAC engineers

Mentoring is the process of transferring knowledge and experience between individuals and groups of people.

By Timothy M. Scruby, PE, Senior Project Manager, Facility Dynamics Engineering, Afton, Va. May 1, 2008

Mentoring is the process of transferring knowledge and experience between individuals and groups of people. In 28 years spent in the engineering profession, I have been exceedingly fortunate to live and work with myriad unique and talented individuals. My mentors and mentees have included family members, employers, coworkers, and friends.

I firmly believe that the process of mentoring is the best way to grow better HVAC engineers and people. I learned from mentors a long time ago that it is easier to learn from other people’s mistakes (and successes) than having to do it all yourself.

For example, when I was a young engineer, the firm that I served had an experienced engineer that was nearing retirement. It was quickly clear to me that if I could learn 10% of what he thought he had forgotten, it would be a huge amount of new knowledge for me. I tried asking him questions about what I was doing. Sometimes I got help, sometimes not, usually depending on how busy he was and how he felt that day.

He had reached the point in his career where he was given the difficult and tricky assignments (the ones that I enjoyed) and he always had the right answer. Eventually, I figured out that he was tired of the production side of doing the plans and specs. I lobbied with our management to let him do the concept work and for me to do the execution. After that, we made a great team because I was good at the production side (not bored with it yet) and I could make his life easier by removing these tasks. In return, I received his attention, the things he thought he’d forgotten, and all the war stories that allowed me to learn and benefit greatly from his experience.

If you can’t find a mentor don’t be afraid to teach yourself. You can do it if you have the will and the patience.

On-the-job training

There are a few essentials for HVAC design engineers. This list also is known as “what they didn’t teach you in engineering school.”

HVAC engineers need to be well-rounded. They need exposure to all the design disciplines so that they know how to interact and coordinate with them (and keep them honest). A good engineer needs to know what is practical and possible within other disciplines. Some examples of this type of knowledge:

• How do you know what depth to allow for a reflected ceiling grid? Light fixtures?

• Where do you get dimensions of structural shapes and bar joists? Can you cut a hole in an I-beam to make a pipe go through it?

• When does a rooftop air conditioning unit need a starter? When does it need a disconnect switch?

• How does the waterproofing and support for a roof curb work? How is ductwork running across a roof properly anchored to the structure and waterproofed?

• What types of materials and insulation are applicable in which envelope systems? Where can glazing or insulation with better thermal characteristics be applied to reduce HVAC loads and thus first and operating cost?

• Where do you need vapor barriers or active means to control condensation on and in building envelopes?

Organized design process

HVAC engineers need to learn an organized design process. Here are some key elements:

• Recognize and document project and owner requirements and constraints from the project program or owner project requirements document. If these documents don’t exist, discuss the project with the owner or architect and establish them.

• Identify, document, and evaluate candidate system types to meet requirements for the types of facilities that your firm designs. Learn the codes and non-mandatory guidelines that establish best industry practice.

• Know realistic rules to rough-size systems for evaluation purposes early in the design process. (Also learn when and how to perform the detailed calculations that establish the final equipment selections.)

• Evaluate equipment options and vendors that give the best value for your project.

• Prepare process flow diagrams and general sequences of operation. This requires detailed knowledge of controls and how systems work. In my opinion, it is a mandatory requirement that design engineers understand how the systems they are designing will safely function to meet the project requirements.

• Prepare a basis of design narrative to convey your analysis and proposed design to others to build consensus with the design approach to meeting the project requirements.

• Plan and organize a set of drawings and specifications to be efficiently produced.

• Perform equipment sizing calculations that result in equipment that is realistically sized—not grossly oversized, and not undersized. An engineer must learn the appropriate safety factors in each situation. In some cases, additional safety factors result in increased performance at marginal additional cost and is advisable. In other circumstances, excessive safety factors are synonymous with increased cost and poor performance.

• Prepare equipment, piping, and duct arrangements that allow efficient installation, maintenance, and, ultimately, replacement. Engineers must learn and consider the impact of system arrangement over the lifecycle of the facility that they are designing. Requiring and paying the installing contractors to do coordination drawings is not a substitute or excuse for not considering this during the design. (I sometimes think that it would be good for engineers to work in construction and maintenance for a year or two to drive home the importance of this. Commissioning experience is good for this, too. A system that is poorly conceived will show many of its flaws during commissioning.)

• Prepare equipment schedules that clearly convey the required characteristics of the equipment. Equipment schedules should either convey the unique nomenclature for each item of equipment on the project, or they should provide a naming system to be used.

• Avoid redundancy and ambiguity in contract documents (also called opportunities for error or unfavorable interpretation). A pet peeve of mine is the use of the phrase “capable of.” (I think this never belongs in a specification without clarification. I have seen specifications like “The system shall be capable of field calibration of analog inputs.” This is ambiguous and arguably could be complied by a system requiring a special hardware tool or a software package that has not been specified, or provided.)

• Quality control: This includes each designer, draftsman, spec writer, etc., self-checking his or her own work by proofing and red line/yellow out, plus peer review of drawings and specifications, documentation of quality control with checklists, and similar measures as the size and complexity of the work demands.

• Get to the field: HVAC engineers need to be involved in the construction of the work that they have designed, even if they are intimidated by it. This means getting out in the field to see it, and answering the questions that come in from the field. Too many young engineers get stuck in the rut of producing drawings and specs while a more experienced field person does the construction administration, with only minimal input from the actual design engineer. While it is better to learn from another’s mistakes, there is no substitute for having to deal with one’s own. That doesn’t mean hang an inexperienced engineer out to dry, but keep them involved, and let them get used to the communication. Engineers who are properly experienced in the field learn that sometimes when a question comes in, there are 10 people, plus rental equipment, standing by waiting for an answer to the tune of hundreds or thousands of dollars an hour. In these cases, it is important to drop work on next week’s design deadline long enough to restore the construction project to productivity.

• HVAC engineers must be trained to know what the computer results should be, and not to blindly take them as gospel or use them as a substitute for field investigation and testing. While today’s engineering tools including great modeling and simulation tools, they are only as good as the input. I have seen things like take-offs made at the wrong scale result in huge errors that are hard to detect from the computer output, but easy to detect if an experienced engineer knows the usual range of the result.

• In doing renovation work involving replacing, modifying, or extending an existing system, the best model that available is the system that is already there. A few well-conceived measurements can be worth a truckload of computer runs.

• The “M” words—marketing and management: Many technically inclined engineers hate these, but at some point in their careers these are essential skills. Engineers need to be exposed to and responsible for budgets on their projects, and as soon as practical, involved in marketing and sales. This means training and experience in verbal and written communication, labor and expense estimating, and presentation skills.

Author Information

Scruby performs all elements of design and construction phase commissioning for mechanical, electrical, controls, and process systems as well as managing and mentoring others at Facility Dynamics.

How to be the best mentor

A mentor is defined as “A wise and trusted counselor or teacher.” There are many ways to mentor less experienced engineers; listed below are just a few.

• Remember to teach ethics and morals. You do this by practice, discussion, and explanation. Share the National Society of Professional Engineer’s Creed and Code of Ethics with your mentees. Review it yourself.

• Remember that as a mentor, you will learn as much by teaching as your mentee learns as a result.

• Share your experience and your references freely. You will find that you receive more than you give.

• Teach your mentees to teach themselves and to be mentors for other people. Make them the department expert on a calculation, system, or equipment item. Let them do the research with your guidance. Require them to teach others in your company.

• Assign responsibility for master specifications to younger staff members so that they learn the details of what they mean and keep everyone in the firm up-to-date.

• Patience is a virtue. Remember if you are short or impatient with your mentees, they will be reluctant to ask questions when they need to.

• Encourage interdisciplinary mentoring so that your engineers and technicians learn other disciplines and understand what coordination is.

Mentees at the ready

A mentee is a person who is guided by a mentor. Be sure that you’re a good learner and listener. A few tips include:

• Many mentors require training. Not all knowledge will be easy to get from a mentor. Find a way that you can work with them. Carry their tools if you have to.

• You don’t have to check your ego at the door, but put it in your back pocket. Arrogance and self-importance in a mentee will stop the flow of information from a mentor faster than anything I can think of. (This doesn’t mean that you shouldn’t stand your ground if you are convinced that you are correct. Mentors are not perfect, but you will gain much more from them if you use some respect and humility.)

• Don’t ask questions to save yourself work; ask questions when you are out of ideas. Using this principle, don’t be afraid to ask questions. To a good and perceptive supervisor, this is a sign of strength, not weakness.

• When you are stumped on something and your mentor is not available, learn to find something else to do so that you can continue to be productive.

• Seek learning, challenge, and responsibility. Ask for assignments that you are interested in. Be proactive in finding training classes that you want to attend.

• Huge amounts of information are available via the Internet. Browse magazine archives, professional and technical society publications, and equipment manufacturers’ data.

• Insist on being hands-on. Go see the result of what you have designed. Insist on participating in the construction administration of what you have designed.

On my bookshelf

Here’s a short list of HVAC-related references that I have frequently used during my career.

• ASHRAE Handbooks, Standards, and Guidelines

• ASME B31 Series Piping Codes

• ASME Boiler and Pressure Vessel Code

• Babcock and Wilcox, Steam

• Cameron Hydraulic Data, Ingersol Rand, Sixteenth Edition

• Carrier System Design Manual

• Chemical Engineer’s Handbook, Perry and Chilton, Fifth Edition

• Cleaver Brooks Boiler Book

• Cooling Tower Information Index, Marley

• The Dehumidification Handbook, Cargocaire Engineering Corp.

• Engineering Design Manual, Bell & Gossett

• Fan Engineering, Buffalo Forge Co., Eighth Edition

• Handbook of Energy Systems Engineering, Wilbur

• Handbook of Practical Electrical System Design, McPartland, McPartland, Third Edition

• Heat Transfer, JP Holman

• Hydronic System Design and Operation, Irwin Hansen

• Industrial Ventilation, ACGIH

• Instrument Engineer’s Handbook, Bela G. Liptak


• Mark’s Standard Handbook for Mechanical Engineers, Baumeister, Avallone, Baumeister, Eighth Edition

• Mechanical Engineer’s Handbook, Lionel S. Marks, First Edition

• The National Electrical Code Handbook

• National Fire Protection Agency, National Fire Codes

• The Passive Solar Energy Book

• Spirax Sarco Steam Utilization, Hook-ups

• Trane Air Conditioning Manual

• Water Treatment Handbook, Nalco Corp.