Using PEX for hydronic and plumbing piping
Founded in 1894, Episcopal Homes in St. Paul, Minn., started out as a small rented home for four elderly women. Now, 121 years later, the senior housing organization offers a full range of care and continues to grow. It recently completed Midway Village, a $47 million ground-up expansion project that will serve nearly 200 additional residents and employ more than 100 new staff members, says President and CEO Marvin Plakut. The number of available housing units increased by 60% — from 287 to 455.
Midway Village is a seven-story, post-tension concrete engineered building with 168 units of senior housing in three residences. The Terrace at Iris Park has market-rate apartments with catered living services; Midway Pointe is a HUD 202 subsidized apartment community for low-income seniors; and The Gardens is a skilled nursing and memory care residence. The first floor of Midway Village is a center of amenities for all residents including fitness center, warm-water therapy pool, pub, salon, theater, business center, café and meeting rooms. It also houses Kinder Village, a child day care center with intergenerational programming.
The general contractor for this complex project was Minneapolis-based Benson-Orth Associates. Burnsville, Minn.-based R.T. Moore Co., MN, was selected to do the plumbing and mechanical work.
Established in 2007, R.T. Moore MN is headed by President Elizabeth Moore and has quickly grown to be a multistate mechanical contractor, working in six upper-Midwest states in the commercial and multifamily markets. The company — a women-owned, small business enterprise that is certified in HUD Section 3 construction — is a member of the Minnesota Plumbing-Heating-Cooling Contractors Association and the Minnesota Mechanical Contractors Association.
In spite of an especially severe winter, construction on Midway Village remained on schedule and was completed Nov. 1, 2014, when the first residents began to move in. Both the Terrace and Midway Pointe were fully leased on opening, and The Gardens is at 90% occupancy.
“When I asked about their selection of PEX for plumbing applications, R.T. Moore stated that the spec book permitted any combination of plumbing product types: CPVC, copper and PEX piping,” says Anne Kamiri, special projects coordinator for Episcopal Homes. “The project includes all types of piping in different parts of the building, depending on specific purposes and locations.”
Saving labor and materials
The project kicked off with the underground parking, underground rough-in, as well as sleeve layout with GPS working side-by-side with post-tension structural shoring and bracing as the building went up seven floors, notes Dean Kirchoff, lead mechanical project manager for R.T. Moore. Roughly 480 sleeves were installed per floor using Proset Systems’ sleeving system.
R.T. Moore used plastic pipe in many applications for this project, including 4,080 ft. of 1/2-in. to 2-in. Wirsbo hePEX for the hydronic heating system along with Uponor’s PEX support, which allows for plenum rating and increased hanger spacing. Also used were 32,060 ft. of 1/2-in. to 2-in. AquaPEX for the plumbing system and 2,200 1/2-in. to 2-in. ProPEX EP fittings.
Uponor products were selected for individual residential units as well as other parts of the building. “The labor- and material-savings of plastic pipe enabled us to bring the job in on budget,” Kirchoff, a Master Plumber and 30-year veteran in the plumbing and mechanical contracting industry, explains. “Using Uponor and PEX allowed us the flexibility to route the lines and minimize conflicts with other trades.” Reliability of the system and the company’s warranty of its piping system also were factors.
Additional products for the plumbing and heating systems include: a Canaris duplex, variable-speed pressure booster system for domestic water; 12 high-efficiency Elite HTP EFT 399,000 Btu boilers; an Evapco cooling tower; 23 Taco pumps with variable-frequency drives; 219 WaterFurnace water-source heat pumps; Greenheck makeup air units for the kitchens and a power roof ventilator exhaust system; Trane space heating and cooling rooftop units; fan coil units; a heat recovery unit; and a Dectron dehumidifier.
R.T. Moore selected Associated Mechanical Contractors out of Shakopee, Minn., to install the hydronic and HVAC system.
“The system is a condenser water closed-loop system set up with a dead band on the loop with the water temp between 76° F and 84°,” Kirchoff adds. “Within that range there is no mechanical equipment operating — no chiller or boilers. When the condenser water falls below 76°, the boiler system adds hot water to the system. When the condenser water gets above 84°, the cooling tower adds chilled water to the system. This allows the heat pumps to work within the dead-band range at the maximum efficiency.”
On multifamily projects, collaboration is very important, Kirchoff notes. “We had to work with all the different trades to schedule the tower crane, the skip and the inspections from all the agencies that were involved,” he says. “We were required to have weekly meetings with our three-week-look-ahead schedule and manpower requirements; this was all key to having a successful project.”
R.T. Moore was able to get in touch with Uponor early on to assist with the sizing and sleeve layout locations for each of the plumbing, condenser loop and condensate drainage systems. “We maximized the flexibility of the system design using multiport tees with PEX, thus decreasing the amount of joints in the system,” Kirchoff says. “We also installed risers from the first floor to the seventh floor, grouping the bathrooms and grouping the kitchens.”
While no major problems or complications arose during construction, the project’s various funding and inspection avenues made it a “complex” project, Kamiri notes. “It involved funding, regulations and inspections from a number of different entities including the city of St. Paul, the Minnesota Department of Health, and the U.S. Department of Housing and Urban Development,” she says. “Occasionally, changes had to be made in the field when required adjustments in one housing component of the project impacted other components.”
Training is key
Once Uponor products were brought to the jobsite, manufacturers representative Fourmation Sales of Rogers, Minn., provided training and certification of the crew.
“Hydronic heating is by far the most efficient way to transport heat energy,” says Dean Corrigan, principal at Fourmation. “Compared to copper piping systems, it features lower material cost, labor savings, similar hanger spacing, a more reliable fitting system, higher flow velocities and less noise. Also, expansion and contraction rates are nearly close to copper when using PEX pipe support. The pipe can be joined without the use of glues, solvents, flux, solder or open flame.”
In addition to onsite training, the rep agency provides training to engineers and contractors at its facility or the contractor’s shop. Uponor provides factory training at its facility in Apple Valley, Minn., which offers learning opportunities in basic and advanced hydronic heating and controls, residential and commercial radiant floor heating/cooling systems, snow/ice-melt systems, commercial hydronic distribution piping and plumbing piping systems, and residential fire sprinkler systems.
“Hydronic heating is most certainly a growth area for us,” says Tim LaDuke, outside sales for Fourmation. “Moving water is the most efficient way to convey thermal energy. It also offers a higher degree of comfort along with clean and quiet operation.”
Episcopal Homes is very satisfied with the final result. “This project was successful because of the experience of its contractors and their superior workmanship,” Kamiri says. “The contractors responded well to the high expectations and standards of Episcopal Homes. The project has received much praise and recognition from its community.”
Kirchoff adds: “We had a good team of players on the project and when you get a good team that is willing to work together, the whole project runs very smoothly.”
This article was originally titled, “Multifamily collaboration” in the September 2015 print edition of Plumbing & Mechanical.