Miles Ryan P.E

Featured in: Favicon

achrnews.com Favicon

esmagazine.com

Articles

Software vs. Hardwired Interlocks: Part I

2 months ago | achrnews.com | Miles Ryan P.E |Hannah Belloli |Joanna R. Turpin

The devil is in the details. This especially runs true when it comes to the automation of HVAC systems. The slightest nuances, if misunderstood, can have devastating effects. One prime example is the importance of understanding the difference between software and hardwired interlocks. An interlock is a dependency between two processes. Process 2 cannot operate unless Process 1 is in a certain state.
Inadequate Project Scheduling, Premature Functional Testing, and End-of-Project Chaos

Jan 20, 2025 | achrnews.com | Miles Ryan P.E |Hannah Belloli |Joanna R. Turpin

A very common task incorporated into a commissioning process during the early stages of construction is schedule coordination. The task includes the commissioning provider working with the construction team to ensure activities and milestones of interest to the commissioning process are entered into the master schedule for the project. A list of common items of interest is provided below. Items with * may require separate line items for each system on some projects.
Unrepresentative DAT Readings Downstream of VAV Boxes

Jan 8, 2025 | achrnews.com | Miles Ryan P.E |Hannah Belloli |Joanna R. Turpin

For years, the conventional VAV control sequence included the reheat valve controlling directly to space temperature. More and more often, discharge air temperature (DAT) sensors are now being installed, and the reheat valve is specified to control the DAT to a setpoint (see Figure 1). That DAT setpoint is then reset to maintain space temperature at its space heating setpoint.
How to Do Filter Differential Pressure Alarming the Right Way

Oct 27, 2024 | achrnews.com | Miles Ryan P.E

BAS monitoring of the differential pressure across a filter within an air system is commonplace. The differential pressure across the filter will increase as the filter gets loaded. If it gets too high, an alarm can be generated on the BAS which will inform building operators it is time to replace the filter. This approach is commonly viewed as superior compared to changing filters at set time intervals. Unfortunately, it is rarely, if ever, implemented correctly.
Collaborative Sequence of Operation Development

Sep 30, 2024 | esmagazine.com | Miles Ryan P.E

The typical evolution of an HVAC system’s sequence of operation (SOO) entails the design engineer writing the narrative for inclusion in the design documents. The controls contractor will then include a SOO in their submitted shop drawings. The worst-case scenario is that the temperature controls contractor replaces the designer’s SOO with something less-than-appropriate and it gets approved.
Using MAU Cooling Coils as Dry Coolers, Part III

Aug 13, 2024 | esmagazine.com | Miles Ryan P.E

This is the third and final installment in the series on using makeup air unit (MAU) cooling coils as dry coolers. Part I introduced the concept and provided a case study with an air-cooled chiller and a chilled water system which utilized glycol.
Using MAU Cooling Coils as Dry Coolers

Jul 10, 2024 | esmagazine.com | Miles Ryan P.E

The previous article introduced the concept of using a chilled-water cooling coil, located upstream of a heating coil within a makeup air unit (MAU), as a dry cooler. This allows for more efficient and stable operation of a chilled water system at lower ambient air temperatures. A case study was presented for a high-rise condominium, which required chilled water during ambient temperatures down to 10°F.
Using MAU cooling coils as dry coolers, Part 1

Jun 5, 2024 | esmagazine.com | Miles Ryan P.E

Over the past several years, I’ve worked in several high-rise condominiums that utilize a makeup air unit (MAU) that conditions 100% outdoor air to a neutral dry bulb temperature (~70°F) and suitable dew point (<57°). The MAU ducts adequate ventilation air directly into the individual condos. It also keeps building pressure slightly positive.
The trouble with troubleshooting new construction commissioning

Apr 18, 2024 | esmagazine.com | Miles Ryan P.E

Troubleshooting complex issues in the field is one of my favorite parts of the job. I enjoy the “ah ha moment” when it all comes together, and the solution becomes obvious. I suspect many other commissioning providers feel the same way. If you are working existing building commissioning, troubleshooting is almost always part of the scope and is budgeted for.
Commissioning conversations: Addressing cringeworthy resistance to problem-solving

Apr 15, 2024 | esmagazine.com | Miles Ryan P.E

The commissioning process often includes the commissioning provider giving recommendations to various team members to address current or foreseen issues with system operation. Such recommendations are not always taken blindly, which is not a bad thing. Ideally, recommendations for addressing complex issues will prompt healthy collaboration between team members who all keep an open mind and remain committed to doing the right thing for the building.