Meeting/Event Information



Add to Calendar

January 14, 2020

University of Minnesota Phillips-Wangensteen Building Tour
January 14, 2020
8:00 AM - 10:00 AM
Phillips-Wangensteen Building
516 Delaware St SE
Minneapolis, MN 55455
Mechanical Systems Tour

$20.00 Registration

$0.00 Student Registration

Join the MNASHRAE Chapter for a tour of the University of Minnesota Phillips-Wangensteen Building on January 14th to learn about the mechanical system of this 1970s building.


The Phillips-Wangensteen Building, PWB, is a 15-story building comprised of research labs, medical clinics, classrooms, and offices. It was originally constructed in the 1970s and has had minimal large-scale mechanical upgrades since the original construction. The building consists of (3) main mechanical rooms which are located on the basement floor, 10th floor, and 15th floor. The original HVAC design was constant volume with hot water reheat and all pneumatic actuation and terminal control.

When the Health Science Education Center, HSEC, building was designed, portions of floors 2-5 in PWB were involved in the scope since HSEC and PWB are connected via pedestrian skywalks on several floors. The PWB renovations involved the replacement of the existing constant volume reheat units with VAV units as well as a complete terminal unit DDC upgrade.

The University wanted to optimize the capabilities of the new VAVs and electronic controls, so a secondary project was implemented to upgrade the basement level AHUs in PWB. The basement mechanical room consists of (9) significant AHUs, which serve conditioned air primarily to floors B-5 of PWB. AHUs 2-9 were part of this secondary project since they have similar operating parameters. To increase unit efficiency and create additional redundancy, it was decided to gut the existing AHUs and replace all the interior components as well as the automation controls. Instead of operating each unit independently, it was also determined that AHU 3 & 9 could be completely removed and AHU 2, 4, & 5 could be manifolded to operate jointly and AHU 6, 7, & 8 could be manifolded to operate jointly.

The interior improvements consisted of the replacement of all the dampers, actuators, coils, fans, and sensors. The same unit housings were reused. All existing AHUs utilized pneumatically controlled non-insulated dampers, cooling coils, steam face and bypass coils, and Joy supply fans. Although the units were on the centralized building automation system, there was limited customization that could be done to optimize unit efficiency. New low leakage insulated dampers, cooling and low temp hot water heating coils, and (6) unit fan walls were installed in each unit. Duct work was reconfigured to allow the (2) manifolded systems on both supply and return air sides. All new electric actuation was also installed to modulate coils and dampers.

To ensure as much redundancy as possible, the main duct risers to each floor were coated with duct sealing material to limit leakage as much as possible. This allows more delivery air which results in lower fan speeds and increased redundancy.

In addition to all the mechanical improvements, there were large quantities of new duct pressure sensors installed throughout the affected floors to ensure both supply and return air pressures are optimized for normal building operation. We also have the ability to lower the outdoor air levels by using air flow measuring stations and mixed air pressure sensors. The commissioning process will be on-going for some time as the system is more complicated than a standard AHU replacement. It is our intent to operate each manifolded system based on common duct pressure sensors so that each unit is operating at the same speed. We also intend to utilize the electronic controls to implement night setbacks where possible.


Future Meetings


September 30, 2020

2020 MN Energy Expo - Virtual Meeting

September 30, 2020
8:30 AM - 12:00 PM


Join us virtually to learn about best design practices in response to COVID-19

October 20, 2020

City of St. Paul - Climate Action and Resilience Plan

October 20, 2020
11:30 AM - 1:00 PM


Benchmarking, high performance codes, retrofitting existing buildings and more!