A business owner looks forward to the day when he can hand increasing amounts of responsibility over to his managers. For the comfort system installation in this latest “Home of Distinction,” Russ Donnici, president, Mechanical Air Service, did just that. He took a step back, and let his team take the reins on the installation of a geothermal system in a 12,600 sq.ft. home in Atherton, CA.
This project was handled solely by Mechanical Air Service’s second-generation management team of Matt Donnici, vice president of construction, and Scott Larson, vice president of service. Both men are International Ground Source Heat Pump Association (IGSHPA)-certified, and took full charge of the design of the geothermal system, equipment selection, installation, and commissioning.
“We call these ‘Homes of Distinction,’ because they’re large, with magnificent interiors; this home is no different,” says President Russ Donnici, who last won a Quality Home Comfort Award in 2008. The developer — MVA Construction Co. —spared no expense on the home. It’s a traditional French-style home that expands over four acres, in one of the highest priced real estate regions of the U.S. The team’s comfort design included accommodating a 1,150 sq. ft. pool house and swimming pool.
Giving total project control over to Matt and Scott was an example of Russ Donnici’s belief in letting managers manage. When Contracting Business.com interviewed Donnici in 2011 for his thoughts on manager excellence, he told us that both Matt and Scott — and his daughter, Chief Financial Officer Danielle Donnici Larson —possess absolute integrity and honesty, and solid decision-making skills.
“I had complete confidence in Matt and Scott. They’re both well-trained and motivated individuals, and a great team to work with,” he boasts.
Regarding the project development, it would soon become something bigger and better than originally imagined.
“This project was supposed to be a conventional HVAC system,” Russ adds. “However, Matt educated the client on the energy efficiencies and benefits of a geothermal system and the opportunity to become a ‘net zero’ energy home, one that produces all the power and hot water it needs through the use of ultra-high efficiency geothermal equipment, as well as solar photovoltaic (PV) for power and solar thermal for hot water. The home generates all its own power without the need of the utility grid.”
Team and Client See Eye-to-Eye
With that recommendation, the team was certainly on the same page with the homeowner, who has chosen to remain anonymous. He told the MAS team that the system had to be the highest efficiency on the market. Comfort, quiet, energy efficiency, as well as great indoor air quality (IAQ) were to be essential elements.
Dual Built-up System
The comfort system draws its heat from 30 wells drilled at 325-ft. The home’s ground loop is divided between the right side of the home, which uses the heat and cooling from 13 of the loops, and the left side, which uses 17 loops for the home and the swimming pool.
Two Grundfos Magna variable speed pumps are used, each with a flow meter and a motorized zone valve.
“This project was a great learning experience, due to the fact that some new ideas were tried, and were successful,” Matt Donnici explains.
“Normally, when we do geothermal jobs, we use a flow center with each unit. In this project, we designed a built-up system, with piping and variable speed pumps for higher efficiency. We often install variable speed pumps on radiant systems, but this was our second for a geothermal that went with a built-up system. With the variable speed pump system, the pump matches the load, so that when a valve opens on the right side of the house, that pump controls three units.
“When a geothermal unit turns on and opens its valve, the pump sees that pressure change and ramps up to compensate. When the valve closes, the pump ramps down. It provides greater energy savings in a more efficient operating system.
“A variable speed pump saves money, because electrical usage is less. In this home, it provides a better functioning system, based on my performance testing. If it were a single-speed pump it would be on full blast or off. This unit matches the load accurately.”
Six ClimateMaster Tranquility 27 two-stage, 4-ton geothermal units and one 2-ton units are the heart of the system.
The home’s systems were commissioned, including air balancing with a flow hood, and testing and recording static pressure and temperature splits. The entire geothermal water-to-water system was balanced using Caleffi circuit setters.
As a value-added service, the home was monitored and tested for carbon dioxide (CO2) levels, to verify ventilation efficiency. CO2 levels were measured using a Critical Environment Technologies YESAIR data logger, that also records temperature, humidity, and carbon monoxide.
In addition, the home was tested using an RAE Systems hand-held VOC detector capable of measuring total VOCs down to 1 part per billion.
Green System Design
Mechanical Air System’s goal in designing the home’s HVAC system was to integrate as many “green” energy related items as possible. The systems were engineered for maximum heat load, plus some reserve, which is expected during times when the homeowner would be entertaining guests. “I base load on average usage and client expectations,” Matt Donnici explains.
No energy penalty occurred, since the systems all have two-stage compressors and variable speed motors, and the extra capacity is in reserve until needed. In addition, the Crestron home automation thermostats were programmed with a 3.5F dead band between the first and second stages, instead of the normal differential. Each of the geothermal systems has an Aprilaire zone system, which serves 19 interior temperature zones.
The duct work and grille discharge air velocities were designed to maintain quiet operation. One airflow challenge Donnici and Larson faced was in engineering the airflow into the home’s theater. The solution was to oversize the registers and ductwork for noise reduction.
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All systems were equipped with Ultravation high intensity UV light systems for improved indoor air quality, and Honeywell electronic air cleaners. The intensity of the Ultravation UV light systems was tested with a radiometer for output verification. A laser particle counter, and a TSI Dust Trak aerosol monitor were used to determine the efficacy of the electronic air cleaners. There were no problems with the startup or commissioning of the systems.
“The plumbing in the U-shaped home was also split into two zones. I designed two solar thermal systems for the house. On the roof, on the right and left points of the ‘U’ are Heliodyne panels that go to a 120-gallon tank for each side of the home. The solar PV system by the electrician generates all the power needed for the home, resulting in a net-zero energy home” Donnici says.
With the Right Team, It’s Easy
When you have a great team, great things happen. This exclusive home now features a high level of exclusive comfort, thanks to Matt Donnici and Scott Larson. Their training and experience prepared them to meet the high efficiency requirements of their customer, and they moved forward with the confidence found in winners . . . especially in Contracting Business.com Quality Home Comfort Award winners.
PRODUCTS KEY TO SUCCESS
- Aprilaire 6404 zone panels
- Caleffi 3-in. hydro separators
- Caleffi circuit setters and zone valves
- Six ClimateMaster Tranquility 27 two-stage, 4-ton geothermal units; two, 2-stage units
- ClimateMaster Genesis geothermal water-to-water 5-ton geothermal unit for pool heating.
- Crestron home automation thermostats
- Critical Environment Technologies YESAIR meter
- Flatplate heat exchanger for pool
- Grundfos Magna 40-120 variable speed pumps for ground loop
- Heliodyne solar thermal hot water systems
- Honeywell F300 electronic air cleaners
- Ultravation UV light systems
- Mitsubishi Mr. Slim ductless split system for AV room
- York AM240AT fan coil with Tecumseh AKA946 condensing unit for wine room refrigeration.
- RAE Systems VOC detector