Connecticut contractor installs systems in tight new home
By John MacKenna
Every now and then a really interesting installation job comes along that gives a company a chance to do something spectacular.
TriTech Mechanical LLC, of Stamford, CT, is working on the leading edge of hydronics installation at a new construction project in Greenwich, CT, installing an Energy Kinetics Accel CS boiler to heat an unusual 4,500 square foot new construction home with in-floor radiant and hydro air.
The new home is built with exterior walls made of insulating concrete form (ICF) blocks, which provide exceptional insulation compared to other construction types, such as wood frame. ICF walls are made by stacking hollow foam ICF blocks that are reinforced with steel and stay in place to perform two functions: they serve as the form into which concrete is poured, and the provide layers of built-in foam insulation on the either side of the concrete. In this home the, ICF construction extends from the footings to the roof.
The resulting construction provides numerous advantages. The strength of the walls is great enough that ICF construction is recommended in areas prone to tornadoes, and the insulation level is high, which is an important consideration affecting the heating and cooling loads.
Another interesting feature of the Greenwich house is its radiant floors. The homeowner chose to use WarmBoard floor panels throughout. WarmBoard floors double as a subfloor and are preformed with grooves that simplify the placement of PEX radiant tubing.
TriTech co-owner Tony Tamburro loves an interesting job, and when an architect acquaintance sought his help for this unusual new home, he was happy to help. The homeowner was looking to complement the tight outer shell and radiant heating with super high-efficiency equipment that would deliver a combination of superb comfort and low year-round energy costs.
Tamburro is one of three owners of TriTech, which was founded 11 years ago. The company specializes in residential heating and cooling, and gets its fair share of high-end projects and customers.
The Energy Kinetics support team and Territory Manager Mark Santangelo are assisting Tamburro by doing a complete energy analysis on the home, considering the square footage, the insulation factors, the 12-foot ceiling heights, the window sizes and more. Energy Kinetics used its analysis to generate a heat load calculation and identify the correct boiler size. With the home’s well-insulated shell, the domestic hot water was the largest load factor and actually drove the boiler sizing. The Accel CS incorporates an outdoor temperature sensor and modulates its output between 50,000 and 200,0000 BTU. The system vents into a polypropylene chimney at about 150°F. The condensate line is outfitted with a neutralizer and drains into the home’s main waste line.
For this job, the wall-hung Energy Kinetics Accel CS powers the radiant floors, the hydro air and the domestic hot water. The Accel CS is a natural gas-fired condensing unit that achieves 95 percent efficiency with the help of the Hybrid Energy Recovery, which purges remaining heat in the boiler into a storage tank or heating zone. The boiler’s Energy Manager module is located behind a panel on the case and can be controlled with a set of buttons on the exterior. A technician can easily read the boiler water temperature, flue temperature and operational history and set the boiler curve.
The boiler feeds a manifold that directs heated water to the hydro air system, the domestic hot water and a buffer tank for the radiant systems. During heating season, the radiant buffer tank will maintains a temperature of 125°F to 130°F to support the radiant zones and prevent short cycling.
A Taco PC705 variable speed pump mixing control connected to an outdoor sensor manages the radiant system and varies the speeds of the injector circulator feeding the radiant zones to modulate temperatures. The radiant system uses a Taco Viridian high-efficiency pump with an ECM motor and changes speed based on the number of open zones. The piping is primary/secondary using closely spaced tees.
Tamburro builds his own manifolds on site using a T-Drill system. He says he loves the mechanical aspects of boilers and piping and is fascinated with all the gadgetry that works together behind the scenes, while the homeowner touches only the thermostat.
Tamburro finishes his hydronic projects with a signature touch that his customers really appreciate: He paints the piping close to the manifold in distinctive pattern, with the supply piping red and the return piping blue. Tritech also fabricates small storage boxes from sheet metal and hangs them near the machinery to store the user manuals and make TriTech’s contact information readily visible.
Tamburro also installed a Carrier Infinity system for the air conditioning and hydro air. It consists of three stacked units: the air conditioner coil, the air handler with an ECM blower, and the hydro air coil. TriTech mechanical fabricated the ductwork with a plasma cutter system.