Library cooling system to experience shutdowns

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By Jennifer Garcia

Patrons visiting the Mesa Public Library during the next couple of months should prepare themselves for what might be some uncomfortable conditions.

The county has hired a contractor to improve the cooling capabilities of the library’s heating/cooling system.

As a result of this work, the air-handling unit will be shut down intermittently from beginning Monday through June 30.

Shutdowns will be kept to a minimum and will last between one to eight hours per 24-hour period. Work will be done 8 a.m.-5 p.m., Monday through Friday.

No weekend shutdowns are anticipated.

“We are expecting improvements from this,” Library Manager Charlie Kalogeros-Chattan said. “We are grateful that people are willing to just go through the experience with us on the days the system is shut down. We’re sorry that people have to go through this.”

Kalogeros-Chattan said that the other choice was to shut the library down, but she tries not to do that.

“We decided that since the shutdowns will be of a shorter duration, it was better if we just kind of stay open,” she said.

She also said she wants to forewarn the patrons of when the shutdowns will happen and encourages patrons to ask her any questions that they might have. The library website will give as much advance notice as possible regarding the shutdown schedule to help patrons in planning their library visits.

In addition, during shut down periods, posters will be displayed at the entrance and throughout the library.

The Mesa Library was constructed in 1994. At the time, to keep within the budgetary constraints, the Heating, Ventilation and Cooling (HVAC) system was changed from a refrigerated air system to an evaporative system.

Wayne Kohlrust, internal services manager/project manager, stated that several years ago one of the two circulation coils in the air intake plenum froze over a winter.  The system ran on the one remaining coil, decreasing the cooling capacity for two summers.  

During the winter of 2006/2007, upon learning of this condition, repairs were then scheduled, a replacement coil was fabricated and the work was completed during the winter months.

During the following summer of 2007, the Library experienced a high number of complaints due to excessive heat and humidity in the building.

A Request for Proposals for Retro-Commissioning which is an in-depth study of deficient Heating, Ventilation and Air Conditioning (HVAC) systems, was issued in July 2007 in order to diagnose the cooling problems and then design and recommend solutions. It was awarded to Total Building Commissioning (TBC), (now Spectrum Engineering) out of Salt Lake City, Utah in December 2007.

One amendment for additional design for correction work to the system was processed and the contract value is now at $56,000.

Over the next two months library staff provided specific information that included date, temperature and humidity information and as-built building plans were sent to TBC. TBC conducted an on-site investigation of the Library on Jan. 22 and 23, 2008.

They performed a walk-through of the facility, talked with facilities maintenance staff and library staff, reviewed the information and provided some thoughts on the current conditions and a path forward.

TBC identified 35 additional Input/Output points necessary to better monitor and operate the system.

While spring/summer 2008 did not see the 90-plus degree temperatures and rain of the previous year, the cooling of the building improved substantially compared to 2007. The final piece of the needed work is to enlarge the Air Intake part of the system.

There are several restrictions in the air intake system, which reduces the desired airflow and creates turbulence. Also, the air flows through the heating coils.  This is not an issue during the winter, as the cooling system is off but is during the spring and fall when both the heating and cooling systems are both needed, many times on the same day.

The same ductwork supplies heating, cooling and outside air into the system, so if the building needs cooler air, this air is heated as it passes through the heat coil. A bypass damper will be added as part of the work to re-direct the air around the heat coils, providing the cooling desired.

JD Zentz of Rio Rancho has been awarded the work to perform the HVAC Intake Enlargement work. The low bid was $93,238. The work is scheduled to be completed in June.

For information or if you have questions, call Kalogeros-Chattan at 662-8242, or Kohlrust at 662-8989.