HVAC Engineering Firm Staff Members and Basic Responsibilities

David R. Olson, PE, LEED AP

November 12, 2015

The following represents a typical small engineering firm team make-up and associated responsibilities. There are likely to be more tasks required of each position than listed below. The various duties listed are possible, but not inclusive.

  • Principal – This person usually is the company owner and principal engineer. He is responsible for all aspects of the company management and operation. As such, he performs many diverse functions, such as:

    • Develop relationships with clients, such as architects, contractors, developers. This would involve telephone conversations, meetings and social events both inside and outside of the office.

    • Attend project walk-throughs in preparation for bidding for mechanical design services.

    • Negotiate fees for engineering projects and execute agreements for work.

    • Maintain necessary company staff, hire/fire staff members as dictated by work load, performance and desired growth or contraction.

    • Provide performance reviews of staff members and make adjustments in salary and benefits as deemed necessary or appropriate.

    • Schedule production staff, determine priorities for project completion and/or progress. Assign staff members to particular projects which most suited their skill set and experience.

    • Oversee the project development. Discuss system selections with project engineer. Maintain adherence to company engineering policies and standards. Provide direction and technical assistance.

    • Perform quality assurance reviews of all projects upon completion.

    • Meet with clients, developers and others to maintain relationships and review project deliverables. Coordinate any/all resolutions to construction related difficulties discovered during mechanical systems construction or commissioning.

    • Perform “special” projects, such as peer review of work performed by another engineering firm, plan reviews of work performed by other engineering firms, expert witness and other forensic related projects.

  • HVAC Engineer – These individuals are responsible for the production effort of design projects and perform consulting on new or existing buildings to determine the cause and rectify a deficiency or to determine the appropriate manner to conduct some sort of system enhancement or replacement. Some examples of engineering responsibilities are as follows:

    • Organize production effort of in-house design team of designers and drafting staff involved in a particular design project.

    • Attend project meetings with clients and representatives from other engineering disciplines involved in the project.

    • If project is a new construction project, study the proposed building and site plans and determine suitable HVAC system (and plumbing/fire sprinkler) alternatives. Determine an estimated probable cost of various system choices. Make a recommendation for a system type, based upon the building orientation, proposed structure and finish materials, cost, availability of mechanical equipment room space. Identify special needs of the building, such as server rooms, elevator and electrical rooms, IT closets, etc. and determine the most appropriate manner to achieve satisfactory temperature and/or humidity control for these various rooms or areas.

    • If the project is a remodel or a remodel-addition, visit the existing building and perform a mechanical field survey. The goal of the survey is to fully understand the existing mechanical (and plumbing/fire sprinkler) components, layout and systems of the existing building so that you can design either modifications to this building, or interface new addition systems with those systems and utilities that already exist. In some cases, an addition might utilize capacity that already exists in central heating and cooling systems within the base structure. In other cases, you might determine that the most favorable alternative would be to provide new, independent HVAC systems. The Owners Project Requirements will guide you as to the appropriate level of field investigation. The engineer must determine if an existing system is appropriately sized and/or configured, and if this system can accommodate additional building area, or a change of use.

    • Perform a code investigation to insure that proposed system alternative did not violate provisions of the governing building codes.

    • Select appropriate system type from analysis performed previously, which is consistent with the Owner’s budget and expectations. Examples of system types are vast, some examples include:

      • Central heating system utilizing gas fired boilers, pumps, air and expansion control, and insulated piping distribution network;

        • Boilers may be one of many different designs such as condensing direct vent boilers, non-condensing direct vent boilers, forced air fire-tube boilers, forced air water-tube boilers, bent-water tube atmospheric boilers, electric boilers, wood fired boilers.

      • Central chilled water system utilizing water or air cooled chiller, pumps, air and expansion control and insulated piping distribution network;

        • Chillers may be one of many different designs such as centrifugal chillers – one or multi stage, with or without economizer, absorption chillers, air-cooled chillers with any number of compressor alternatives, screw chillers – both water or air cooled.

      • Condenser water systems, utilizing open cooling towers with one of multiple designs, or closed loop fluid coolers;

      • Central station air handling systems, with or without heat recovery functions. Air handlers may have heating water coils, chilled water coils, filtration, humidification, and controls. Air handler could be located inside the building, on the roof or on grade. Air handler may also be provided with DX cooling, evaporative cooling, or could be a heat pump;

      • Four-pipe fan coil systems, with or without a dedicated outdoor air ventilation system;

      • Two-pipe fan coil systems, with or without a dedicated outdoor air system, perhaps with heating-cooling seasonal changeover;

      • Water source heat pump system, with or without a dedicated outdoor air ventilation system;

      • Variable Air Volume (VAV) system utilizing single duct terminals without reheat, or using the same with reheat, or using fan powered VAV terminals with electric reheat or hot water reheat systems;

      • Hydronic heating systems using radiant floor heating, baseboard radiation, cabinet unit heaters, unit ventilators, overhead radiant panels, horizontal or vertical unit heaters;

      • Radiant cooling systems and controls;

      • Chilled beam cooling systems;

      • Air turnover systems with either gas or hydronic heating;

      • Evaporative cooling systems, either direct evaporative cooling or direct-indirect evaporative cooling systems;

      • Ground source heat pump systems, sometimes called geothermal systems, either water to water or water to air, with necessary zoning and distribution;

      • Packaged rooftop HVAC systems, either heating only, or heating-cooling systems;

      • Ductless split heating and cooling systems, either independent systems, or systems with multiple evaporator cassettes;

      • Variable refrigerant flow systems;

      • Packaged terminal air conditioner systems;

      • Computer Room Air Conditioning (CRAC) systems;

      • Constant volume systems using furnaces and remote condensing units (such as Breen utilizes),

      • Electric baseboard radiation, radiant panels, wall heaters, cove heaters, or convectors

This list is virtually limitless, and new system alternatives are developed by engineers and manufacturers all the time. Engineers must be familiar with all of the above systems in order to appropriately recommend systems for their clients, regardless of the size or scope of their application.

    • Perform an overall system layout, identifying key elements of the HVAC systems and their locations. Alert client to any special space needs for equipment rooms or shafts. For hydronic systems, determine piping method and general routing.

    • Coordinate utility requirements for HVAC (and plumbing) systems. Communicate with structural and electrical disciplines to insure proper accommodation for mechanical systems.

    • Oversee design and drafting staff assigned to this project.

    • Perform red-lines of developing contract documents. Prepare submittals for schematic design, design development and construction drawing phases of the project.

    • Prepare equipment schedules, including identification of and description of all necessary mechanical (and plumbing) equipment and accessories required for the project. Work with equipment sales representatives to insure proper application and specification of equipment and accessories.

    • Identify standard details to include within a detail sheet. Prepare unique or special details required to describe specific construction requirements for a project. Determine locations where section cuts must be completed to allow understanding of the design intent by bidding contractors and others.

    • Prepare written specifications for project. Specifications will often include an “outline specification” at early schematic design or design development phases of project, and a full specification produced in the later stages of project design.

    • Prepare control system specification, including appropriate sequences of operation.

    • If necessary, prepare fire sprinkler system specification, including fire pump and/or standpipe systems.

    • Attend Pre-Bid and Pre-Construction meetings at project site. Answer all questions posed by bidding or successful contractors. Prepare required addendums and/or modifications to the contract documents.

    • Conduct mechanical site observations to determine progress completed by contractor and insure construction compliance with plans and specifications.

    • Perform, review or assist with system commissioning activities, including Test, Adjust and Balancing.

    • Perform due-diligence on existing structures, determining the operating condition and characteristics of building mechanical systems, including recommendations for repairs or replacement, including estimated probable cost to perform this work.

  • HVAC Designer – These individuals perform many design tasks. There are both HVAC and plumbing designers working in a typical mechanical engineering office. Sometimes, the same person may perform both HVAC and plumbing design duties. The performance of these staff members is generally repetitive, allowing these individuals to gain experience, conduct their work efficiently and accurately, and become proficient at the system types that they are exposed to in performing their work. Some examples of design tasks performed by mechanical designers are:

    • Heating and cooling load calculations. These are generally performed on some sort of proprietary software. The two dominant load estimating software packages for commercial HVAC design are Trane Trace and Carrier E20. For those firms performing residential HVAC design, the most common load estimating (Manual D) software are Elite and Wrightsoft.

    • Mechanical equipment selection after system identification by supervising engineer, utilizing results of heat gain–heat loss calculations. Determine physical sizes and weights of equipment and requirements for gas, heating water, chilled water, electrical or other utilities.

    • Determine duct system layout utilizing airflow requirements determined when performing the heat gain-heat loss calculations. Size ductwork for accumulated airflow requirements. Determine duct routing and identify locations for duct transitions, branch ducts and fittings.

    • Size and layout all air devices, sized suitably for airflow requirements for each room or area. Design branch ducts to all air devices, taking care to limit pressure drop and noise. Perform duct pressure drop calculations to verify proper fan size and horsepower requirements.

    • Size and perform final layout of all required HVAC (hydronic) piping system layouts. Perform piping pressure drop calculations to verify proper pump size and horsepower requirements.

    • Select and layout all exhaust systems for toilet rooms, trash rooms, etc. In residential design, layout clothes dryer and kitchen range hood exhaust ducts.

    • Determine flue and combustion air requirements for equipment specified. Layout pipe routing and/or louvers on floor plans.

    • Determine locations of thermostats and other required control devices, and show on floor plans.

    • If plumbing design is included,

      • Prepare plumbing data sheet – determining plumbing water and waste fixture units.

      • Size required water, natural gas and sewer mains for building.

      • Perform floor plan layout of sanitary waste and vent piping, and domestic hot, cold and hot water circulation piping.

      • Size domestic hot water heater, recirculating system and tempering system.

      • Develop plumbing riser diagrams for waste and vent piping, domestic water piping, and natural gas piping systems.

  • Drafting – This individual is responsible for all drawing production. They take red-lines from the engineers and designers and input information onto various floor plans, detail sheets, riser sheets and schedule sheets.

    • Prepare existing condition drawings for remodel or remodel/addition projects;

    • Prepare backgrounds from architectural drawings – removing superfluous information which would clutter the final mechanical or plumbing drawings;

    • Prepare post–construction as-built drawings based upon contractor’s red-line construction drawings. Deliver/post completed record drawings to Owner.

  • Administrative – This person keeps everything afloat. They are responsible for accounts payable and accounts receivable. They normally are in charge of maintaining insurance programs – meeting with agents or brokers and negotiating annual rates, following discussion and input from Principal.

    • Answer phones and greet visitors to office

    • Organize special events for staff members

    • Maintain inventory of office supplies

    • Payroll per established schedule

    • Monthly billing after extracting staff hours from time sheets

    • Maintain hourly accountability worksheets such as project dollar/hour, client dollar/hour

    • Holiday greetings and special announcements