WALKER -- Since Cass County Health and Human Services Department personnel moved into the addition to the social services building in November, the county board and maintenance supervisor have questioned heating system design features.
Tuesday, the board received a report to answer those questions from Eric Linner of Wold Architects and Engineers of St. Paul, who designed the building.
Raising thermostat settings in the third-floor reception area, conference room and some second- and third-floor offices appears to have increased heat in those areas to match that in other parts of the building, said Building and Grounds Supervisor Tom Emery.
Linner reported the boiler system was designed for each boiler to be capable of handling 60 percent capacity.
Today, he wrote in his report to the board, buildings are tighter, heating equipment more efficient and reliable, and there is greater effort to control construction costs. If one boiler fails, outside air intake dampers can partially close to conserve heat the second boiler produces, he noted, increasing its capacity.
If the secondary Health and Human Services Building boiler cannot carry the load, he said, Cass also has the option of using pipes connecting that building to the courthouse heating plant to pipe additional heating capacity from courthouse boilers.
During one 15-degree below zero day this winter, Linner wrote, only 14 percent of the secondary boiler backup supplementary heat was used in the Health and Human Services Building with full air exchange being used.
While there is a potential some of the courthouse's 100 percent backup system might be used for a future courthouse addition, Linner recommended the county gain more cold weather experience with the existing health and human services design before deciding whether to spend $16,000 to $20,000 in materials and labor to exchange the existing 60 percent capacity boilers for 100 percent.
In response to concerns over Health and Human Services Building boilers running frequently, Linner said boilers that run often maintain a constant temperature and avoid tube expansion and contraction, which, in turn, would shorten the boiler life.
He reported water hammering in one boiler turned out to be plastic material, which evidently was in the boiler when it was delivered. The plastic created air pockets, causing the hammering, he said.
That boiler was flushed. The problem ceased.
Linner recommended in the future the county run boiler systems through a test before employees occupy a new building or addition.
At the Health and Human Services Building, human services employees moved temporarily into the addition in October, so their existing space could be remodeled.
They moved back into their original space, and health services employees moved into the addition in November from a separate building, so that move could be completed before winter.
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