The Scottco team was careful not to alter the St. Mary's school building's structural integrity, fire resistant properties and historical value.
The water source heat pump system provides sufficient cooling and heating capacity with individual temperature control for each room.
Noise levels had to surpass accepted standards, so as not to interfere with classroom study.
To fit the heating and cooling sytems within existing spaces, a garage/storage building was used as the mechnical room.
Cake test: the school building's roof provided plenty of room for the ventilation ductwork. The cooling tower was positioned near the building, below.
There's nothing quite like a walk through your old grade school. Images parade through one's memory, and make one long for a return to that simpler time, except for those nasty encounters with the class bully, or trips to the principal's office!
What many of us — depending on our age — do not cherish are the shivers or sweating brought about by the condition of the ancient school boiler or non-existent air conditioning.
St. Mary's Montessori Pre-School and Elementary School in Amarillo, TX, used to be like that, but not anymore. This 30,000 sq.ft. historical building was built in 1916. It had gone 89 years without central air conditioning, and was still using steam boilers and radiators for heat. So when Chad Cummings, project engineer for Amarillobased Scottco Plumbing-Heating-Air-Electrical Services came to visit, he knew the project would pose challenges unlike any he had faced before. This was a real "extra credit" job.
The assignment for the Scottco team — Cummings, special projects manager David Higgins, and company president, Brad Martin — was to bring the outdated system up to date, with little or no disruption of school activities, and give the students and faculty the comfort so conducive to productive learning and working environments.
Scottco and school administrators covered the ABCs of the project right from the start. The cost and timing of the work was a big concern.
"We discussed up front the significant challenges the school would face during the project," says Cummings.
"Other contractors hadn't mentioned the significant cost, and the challenges of meeting the ventilation requirements of a school building. We also advised them on architectural and carpentry needs, building code issues, and overall coordination."
To minimize costs, most of the equipment, piping, and ductwork were left exposed, and an existing storage building was converted to a mechanical room.
PVC pipe was used instead of copper, also in the interest of cost. The project was completed on a cost-plus basis, with a guaranteed maximum that fit within the school's budget.
A big challenge Scottco faced lay in the age and condition of the structure, as well as the available space, which conflicted with the need to make modifications for hangers and equipment mounts.
Communcation was essential, says Cummings, given the high profile quality of the project. An Air Conditioning Committee — formed out of the school's Faith in Action group — needed frequent updates and had to review the ongoing work.
"They were very receptive and approachable," recalls Cummings. "They had a representative who would show up at the drop of a hat if we had any questions."
Cummings says the most challenging aspect was having to do the work while school was in session. On the upside, school administrators agreed to close down half of each floor at any one time as needed.
However, because of the daily usage, and traffic between periods, the Scottco team had to transport their tools and materials to and from the working areas, either when school was out for the day, or when the students were not changing classes.
New Design for Today's Equipment
The system design challenges stemmed from the fact that in 1916, the boiler was the only heating element that had to be accommodated in the available space.
Due to the space imitations of the building, each location for the heat pumps had to be measured, and a unit selected that would provide the design capacity, yet still fit within the physical constraints of manufacturers' required service clearances.
"Each pipe and duct chase had to be carefully located so as not to disrupt the existing floor plan, yet not hinder the systems with excessive pressure drops due to elbows and offsets," says Cummings.
Next began a series of trial-and-error attempts at making the new system fit the existing space. Equipment, air devices, ductwork, and piping were sized and selected so that the system's noise level would be even better than "acceptable" levels. This was critical since the ductwork would be run below the ceiling in working classrooms.
Scottco adhered to American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) recommendations and local codes as they installed the ventilation air system. Life and safety features, such as fire dampers and smoke detectors, had to be designed to maintain the integrity of the building and not present any hazards due to the newly installed system.
Because the majority of the equipment, pipe and duct would be exposed, Scottco adhered to the highest level of installation quality. They also had to maintain the building's historical value. These were original hardwood floors and plaster walls. Therefore, each wall and floor penetration had to be carefully located and cut to prevent cracking and deterioration of the existing plaster wall and wood floors.
"Chrome escutcheons and decorative metal angles were used to enhance the appearance of these penetrations," explains Cummings, "and the joints on PVC piping were cautiously primed, glued, and wiped for a presentable finish, not typical of standard PVC joints."
All duct joints were sealed internally, so as not to have a messy sealant finish, and galvanizedhanger rack material was also cleaned off to make the systems seem less obtrusive.
Energy Efficiency Passes the Test
St. Mary's was built to be compatible with a water source heat pump system. With rooms on the north, south, east, west, and interior exposures, one unit would require cooling while another unit would require heating. Circulating the water allows the transfer of heat from one exposure to another, without needing supplemental cooling or heating from the cooling tower or boilers during the fall and spring seasons, which make up the largest portion of the school year.
"The water system is designed to only allow boiler heating when the water temperature falls below 60F, and tower cooling when the water temperature rises above 85F," explains Cummings.
"This allows the system to operate efficiently for a wide range of conditions without using supplemental heating or cooling."
IAQ Best in Class
Previously, the school teachers would just open the windows to make comfort adjustments. This allowed for outside air, but it also brought dust and allergens into the building.
The new system provides filtered ventilation air, with filters within each unit. This supplies cleaner air throughout the massive building, while still retaining a supply of fresh air.
After Commissioning, System Earns High Marks
The newly installed air and hyrdonic systems were tested and balanced to ensure adequate water and air distribution, and to verify proper operation. Each heat pump was also tested for water flow, airflow, heating, and cooling performance.
The new water source heat pump system now provides sufficient cooling and heating, with individual temperature control for each room. Students and staff can now focus on academics, without the distraction of drafty, uncomfortable conditions.
David Huseman, AC committee chairman for St. Mary's, reports the system is performing well, and operating costs are lower than expected.
"Scottco also installed it for less than we had budgeted for," says Huseman.
"We're happy with the way they went after the cost issues and worked to help us save some money. We're also happy with the way Scottco went about installing the system, and got it done without changing the historical flavor of the building. The design they proposed won the project for them."
Winner at a Glance:
COMPANY: Scottco Plumbing, Heating, Air, Electrical Services, Amarillo, TX
PROJECT NAME/LOCATION: St. Mary's Montessori Pre-School & Elementary School, Amarillo, TX
TOTAL COST: $530,000
KEY CUSTOMER CONTACT: Kevin Wallace, principal, St. Mary's School David Huseman, Chairman, AC Committee
NOMINATION SUBMITTED BY: Cara Hardin, Scottco marketing coordinator
THE PROJECT TEAM: Chad Cummings, engineer David Higgins, project manager Brad Martin, president
PRODUCTS KEY TO SUCCESS: