MNA Constructors, L.L.C.

Facility HVAC Renovation and Repair

A full heating and cooling renovation and repair has been done in this facility consisting of replacing the existing chiller and boiler with five new high efficiency furnaces and DX cooling units. An outside air supply and heated Air Rotation Unit was also installed for the drill hall. The purpose of this HVAC upgrade is two fold: (1) replace the existing HVAC systems with new, more efficient equipment; and, (2) divide the building into full time employee zones and part time employee zones. Each zone is controlled by its own temperature sensor allowing uninhabited areas to be set at minimum temperatures during cool weather and maximum temperatures during warm weather. A DDC control system was installed to allow remote monitoring and temperature control from 88^th RRC headquarters in Ft. Snelling, MN.

Since this renovation required installing all new HVAC ductwork throughout the facility, all existing ceilings and associated lighting fixtures were removed and new ceilings with new light fixtures were installed. This included a large classroom and three office areas in addition to the hallways.  After the new ductwork, ceiling and lighting installations were completed, all walls were cleaned, patched and re-painted.

The old firing range was renovated to office space by providing a new suspended ceiling and new lighting, electrical, and communications facilities.

A new electrical feed and panel were installed, and the system electrical loads were balanced among the new and existing electrical panels.

Masonry Renovation and Window Replacement

The exterior of Building 139 on the Ft. Sheridan campus was completely renovated. Over 17,000 square feet of brick masonry was tuck pointed for maintenance, 20 double unit and 4 single unit steel frame windows were replaced and 4 pedestrian doors were replaced. A 19'x27' boiler room annex with a basement was demolished and filled.

For the masonry repair, all vertical and horizontal mortar joints in the exterior brick walls were ground to 5/8"depth and re-mortared with a trowel finish. Approximately 15% of the brick was spalled or stained and was replaced with salvaged brick of the same vintage. All window sills were removed and re-poured in place to form uniform openings for the replacement windows. All masonry surfaces were then acid washed and sealed.

The replacement windows were aluminum framed with an anodized finish and dual pane low e glass.  The replacement of the windows was ancillary to the project and less than 25% of the project cost.

A damaged brick structural column on the inside of the building was repaired and restored.

To accommodate the demolition of the boiler room, the natural gas service entrance was relocated and interior service piping re-plumbed.

Vehicle Exhaust System Repair

The requirement for this facility was to repair the existing vehicle exhaust system by installing a new vehicle exhaust system in each of 2 maintenance bays for the purpose of operating vehicle engines inside the building with the doors closed.  In addition, ASHRAE standards require that at least 1 ½ cfm of air be exhausted continuously from the maintenance facility. To compensate for all of this exhaust, one new, roof mounted, heated, make up air unit was mounted on the roof to replace the air exhausted from the building by the various combinations of exhaust fans that can be running at any one time.

Due to the large increase in electrical load a new underground electrical service was installed from the public utility primary to the maintenance building via a new 750KVA transformer replacing the 208V feed from the main building. A new 400 Amp electrical panel was installed to feed all of the existing load and the new three-phase load.

The bay lighting was upgraded by replacing the existing fixtures with efficient fluorescent fixtures. A new packaged terminal A/C unit was installed in the office area.