Offices change, accommodating HVAC and plumbing trends

To appeal to various clients and work styles, office building HVAC and plumbing design is shifting

By Consulting-Specifying Engineer January 4, 2022
Courtesy: Arup

Office building insights

  • Office building design is changing as owners and tenants expect more, especially outside air to combat pandemics like COVID-19.
  • Touchless plumbing fixtures address several smart building challenges in office space.

Miles Brugh, PE, Project Electrical Engineer/Manager, ESD, Chicago–Adrian Gray, C Eng, Eur Ing, Global Director – Commercial and Real Estate Sector, HDR, London–Matt Humphries, Associate Principal, Arup, Toronto–John Yoon, PE, LEED AP, Principal Engineer, McGuire Engineers Inc., Chicago


  • Miles Brugh, PE, Project Electrical Engineer/Manager, ESD, Chicago
  • Adrian Gray, C Eng, Eur Ing, Global Director – Commercial and Real Estate Sector, HDR, London
  • Matt Humphries, Associate Principal, Arup, Toronto
  • John Yoon, PE, LEED AP, Principal Engineer, McGuire Engineers Inc., Chicago

Center for Medicinal Chemistry at University of Toronto is a mixed office and lab building using digital twin technology in its design. Courtesy: Arup

What unique heating and cooling systems have you specified into such projects? Describe a difficult climate in which you designed an HVAC system.

John Yoon: The oddest “climate” issues that I’ve seen was in a small office building that was constructed next to a large farm. After construction was complete, it experienced dramatic, unexplainable humidity control issues. The solution was to retrofit dehumidification equipment, but the problem mysterious went away before the equipment was fully functional. We didn’t realize it at the time, but that just so happened to correspond to harvest time. In retrospect, it appears that the farm was growing a water-intensive crop and the excessive irrigation was increasing local humidity levels beyond ASHRAE guidelines for that region.

Adrian Gray: Applied heat pumps, displacement ventilation, geothermal, evaporative cooling, hybrid heat pumps, radiant heating and cooling, underfloor air systems to name a few. Application of some of these systems is contingent on local climate extreme conditions, occupant comfort satisfaction versus load offset, office renovation churn rates, physical spatial constraints and client budgets.

What new indoor air quality requirements do you anticipate in light of COVID-19 and other contagions?

Matt Humphries: Hybrid work is not a trend that will change. How do office spaces adapt? How do they become more energy efficient? And how many computers are logged in at once? We need to prepare now to be able to adapt as our needs evolve. There’s a lot of settling out to do to understand the ideal long-term approach. Office workers won’t be in offices five days/40 hours a week in the majority of roles and positions.

Adrian Gray: Most mechanical HVAC system considerations are based on leading industry resources. For example, ASHRAE guidance documents on COVID-19 are good resources to ensure industry recommendations for minimum safety requirements and protocols. We have seen some interest from clients in using air purification technologies such as Ionizer, but this seems to be subsiding as the pandemic appears to drawing to a close in most geographic locations.

John Yoon: Probably the same thing that everyone else does — compliance with ASHRAE Standard 62.1: Ventilation for Acceptable Indoor Air Quality. We are starting to see that in come up during preliminary tenant lease negotiations.

What unusual or infrequently specified products or systems did you use to meet challenging HVAC needs?

Adrian Gray: Improved particulate filtration, application of UV-C germicidal radiation systems, bipolar ionization technology, enhanced ventilation, localized personalized occupant air delivery and control systems (e.g., NUMA) and improved HVAC zoning considerations for effective air mitigation strategies

Have you specified a radiant heating or cooling system into an office building? Describe the project.

Adrian Gray: These systems can be integrated into building heating and cooling systems, either as primary or auxiliary system considerations. These systems should be considered for evaluation due to their lower energy consumption than conventional systems, however they have limitations in their capacities and effectiveness and must be evaluated with the project team

John Yoon: We’ve specified radiant floor heating systems in office building with tall atriums. This was seen as the most viable solution because we could not effectively condition the occupied area with overhead air distribution and conflicts below the slab meant that we could not specify an in-floor displacement ventilation system.

Describe a smart restroom plumbing system for an office building. What types of products were incorporated to keep occupants safe as it relates to COVID-19?

John Yoon: Touchless fixtures are commonly specified to address this.

Adrian Gray: Touchless fixtures and appliances, hand dryers, toilets, urinals and faucets.

Describe an HVAC ventilation system you’ve worked on or encountered in an office building that included hoods, fire suppression systems or other specialized ventilation systems.

John Yoon: We typically only encounter these types of specialized systems in corporate headquarters buildings where other departments coexist with general office functions in the same building. It might be a test kitchen, a machine shop with welding stations, cryogenic storage facilities, a showroom with industrial laser equipment or a CEO panic room with dedicated air — we’ve seen them all in corporate HQ projects.

How have you worked with HVAC system or equipment design to increase a building’s energy efficiency?

Adrian Gray: Advances in air conditioning component technologies, optimized air delivery (i.e., air horsepower, S.A. temperature delivery, air exchange/mixing), zoning and system segregation (e.g., information technology room standalone versus part of central). Air conditioning component technology enhancements include improved compressor technologies (digital scrolls, modular staged configuration, etc..), fan type consideration (fan array versus single fan), motor horsepower Energy Policy Act (EPAct) efficiencies, enhanced and/or oversized condenser coils (water or air), free cooling technologies, improved cabinet and distribution designs (e.g., thermal and air leakage), optimized duct distribution]

John Yoon: While ASHRAE 62.1 is used to ensure adequate ventilation to an occupied space, the key to energy efficiency to avoid needless ventilation and conditioning when the space is unoccupied.

What is the most challenging thing when designing HVAC systems in office buildings?

Adrian Gray: Segregation of base building and/or tenant systems and zoning to optimize system operations, application of most efficient core and shell building systems to minimize operating costs and ensure proper building conditioning.

John Yoon: Finding room for equipment and the budget to procure it.