Pasadena Public Library: Allendale Branch (Pasadena, CA)


The Allendale building, created as a local clinic, was totally remodeled and opened as a branch library in 1951. This adobe ranch-style building serves as the school library for Allendale Elementary School next door, and serves both students and teachers at the adjacent Blair High School. James Colvard, the Senior HVAC Tech at the Department of Public Works looked to Unico for assistance to modernize the buildings mechanical system.

The existing ductwork proved inaccessible due to the old "Z" Spline ceiling, so no duct repairs or alterations were possible. The libraries existing mechanical system and ductwork had to be abandoned and two new 5 ton Unico heat pump systems were installed.


Unico's modular components easily fit through the existing floor hatch to the crawl space. The split systems were installed in a horizontal configuration and the return air system was reconnected to the existing decorative intake grille made of carved wood. Each unit's 10" round supply air adaptor continued into a "perimeter loop" main duct system, terminating into (30) floor outlets fed by the 2" I.D. Unico sound attenuator flex duct. Pasadena's Building Systems Division required the new systems be remotely monitored and controlled through the cities Andover building automation system. The BACnet field bus connects to the Unico Advanced Control Board to control Heat, Cool, and Fan functions. The system also monitors temperature differential between coil and return air and VOC-CO2 for Indoor Air Quality.


The library manager, Shauna Redmond, is very pleased with the cooling system performance, particularly as the load increases when students file in during after school hours. She also noticed the comfortable even heating of the Unico system as compared with the drafts associated with the old heating system. Regardless of season, Shauna commented that the Library has a very comfortable thermal environment when doors open at 10 a.m.

Equipment Used

  • (2) Unico MB4860L+CB Blower Modules w/ Advanced Control Board
  • (2) Unico MC4860HX Heat Pump Modules, R-410A
  • (2) 5 ton Carrier Heat Pump Condensing Units