Homes on Providence’s historic East Side often come with an enviable address, lovely views and antiquated heating systems. Such was the case last year with a 12,000-sq.-ft. home on the East Side with a view overlooking the state capitol. A new buyer decided to completely renovate the home and install a new HVAC system using Read more
Radiant
Homes on Providence’s historic East Side often come with an enviable address, lovely views and antiquated heating systems. Such was the case last year with a 12,000-sq.-ft. home on the East Side with a view overlooking the state capitol. A new buyer decided to completely renovate the home and install a new HVAC system using state-of-the-art technologies including geothermal, in-floor radiant and hydro-air.
Going with Geothermal
TJ’s Plumbing and Heating, Inc., Attleboro, Mass., a firm with expertise in designing and installing geothermal, radiant and solar thermal systems, was the HVAC contractor awarded the contract by the owner, in conjunction with the home renovation contractor, Parker Construction of East Providence, R.I., which specializes in custom luxury homes. Tim Cutler, owner of TJ’s, has been doing geothermal installations for around 10 years, mostly for high-end homes, both new construction and retrofits, and he has seen a 30% growth in his firm’s business stemming directly from geothermal.
With an aged heating system fired by an oil-fired steam boiler, coupled with the new owner’s desire not to have any HVAC equipment situated outside the home for aesthetic reasons, TJ’s challenge was to deliver the ultimate comfort system without compromising the home’s integrity. To accomplish this task they provided a design-build alternative energy system for both heating and cooling, attaining a comfortable indoor environment year-round with a water-to-water geothermal system as the centerpiece of the home energy system.
According to Cutler, vertical bore holes work best in New England’s rocky soil. With sufficient property available for drilling six 550-ft. bore holes for the geothermal system, TJ’s selected and installed three Bosch-FHP 6-ton, two-stage water-to-water TW071 Series heat pumps in the home’s mechanical room. TW Series units feature a two-stage scroll compressor and floating base pan for quiet, high efficiency performance. Unless peak capacity is required, the units can run at roughly two-thirds capacity, at significantly higher efficiencies than other geothermal heat pumps. For backup heat and domestic hot water needs, TJ’s installed a Viessmann gas-fired condensing boiler.
The home has a total eight bathrooms on three floors, and to keep its floors warm underfoot, as well providing in-floor heat for most of the first floor, TJ’s installed a Viega radiant heat system. The firm also installed seven zones of hydro-air using chilled water for cooling and 120° design water temperature for heating. Custom designed sheet metal was used to fit into the home without compromising the home’s integrity or elegance.
Ensuring high indoor air quality
To ensure the highest IAQ and to also provide radon removal, TJ’s installed a Zehnder ComfoAir 350 unit to constantly change the home’s indoor air. This system works continuously to extract moist, stale air from wet rooms (kitchen, bathrooms, utility rooms and closets) and supply fresh, filtered air to habitable rooms. Up to 90% of the heat in the extracted air, which would otherwise be exhausted outside the home, is recovered by the heat exchanger in the ComfoAir unit to temper incoming supply air. To manually increase airflow if needed, TJ’s installed a wall-mounted Zehnder control.
The Federal tax credit’s importance
Since the home’s completion and occupancy last fall, TJ’s reports that the geothermal system has operated as designed and has fully met the client’s expectations. In addition to the concerns about energy efficiency savings and environmental considerations, a driving factor for many of TJ’s geothermal clients is the 30% federal tax credit, a credit that Cutler, and the geothermal industry, would like to see continued beyond 2016.
Project Details:
General Contractor: Parker Construction, East Providence, RI
HVAC: TJ’s Plumbing and Heating, Attleboro, MA
Geothermal Well Driller: Skillings & Sons, Amherst, MA
Interior Designer: Scarborough Phillips Design, West Warwick, RI
Wholesaler: Delta T, Warwick, RI
Bosch Thermotechnology and TJ’s Plumbing and Heating supplied information for this case study. Tim Cutler, owner of TJ’s, is an Accredited Bosch Contractor. He is also IGSHPA and NATE Geo certified.
For Residential & Light Commercial Buildings Heatspring Learning Institute, in partnership with the Biomass Thermal Energy Council and John Siegenthaler, will soon launch a new “lite” version of their 10-week online course: Hydronic-Based Biomass Heating Systems. The new course will focus specifically on residential and light commercial building systems that use high efficiency / low Read more
For Residential & Light Commercial Buildings
Heatspring Learning Institute, in partnership with the Biomass Thermal Energy Council and John Siegenthaler, will soon launch a new “lite” version of their 10-week online course: Hydronic-Based Biomass Heating Systems. The new course will focus specifically on residential and light commercial building systems that use high efficiency / low emission wood gasification and pellet-fired boilers. The course is designed to be completed in one week, and provides 7 AIA continuing education hours.
This self-paced course focuses on system design. It shows how to use modern hydronic heating technology to enhance the performance characteristics of wood gasification and pellet-fired boilers, while providing safe, efficient operation, as well as unsurpassed comfort.
It covers fuel sources, energy cost comparisons, boiler sizing and selection, venting, thermal storage, auxiliary heat source integration, control concepts, and low temperature hydronic distribution systems. It pulls these design elements together into several complete and fully documented combisystem designs.
Students can ask post questions to John Siegenthaler on a facebook style bulletin board. They can also interact with other students, download PDF files of all course materials for future reference, and test their level of understanding.
After completing this course, heating professionals will be equipped with the knowledge needed to design and install efficient, safe, and reliable heating systems fueled by an abundant and fully renewable fuel source.
The course begins on May 11, 2015, For more information please visit:
LEESBURG, Va. —REHAU announces the launch of its new web application, REHAU Radiant Calculator, designed to provide contractors and wholesalers with a quick material estimate for different types of radiant heating installation methods. Intended for use by hydronics experts already familiar with sizing pumps, boilers, controls and manifolds, the calculator estimates the requirements for Read more
LEESBURG, Va. —REHAU announces the launch of its new web application, REHAU Radiant Calculator, designed to provide contractors and wholesalers with a quick material estimate for different types of radiant heating installation methods.
Intended for use by hydronics experts already familiar with sizing pumps, boilers, controls and manifolds, the calculator estimates the requirements for REHAU radiant floor heating pipe and installation materials based on simple heated area inputs. Features include an intuitive, easy-to-use interface, English (IP) and metric (SI) units, instant calculations and both print and email outputs. In addition, the calculator automatically scales for use on both mobile and desktop devices.
“We developed the REHAU Radiant Calculator to provide our customers with a faster, more convenient way of obtaining a radiant materials estimate,” said Steve Rohrbaugh, applications engineer, building solutions. “Instead of looking up the material factors and manually calculating material requirements, contractors and wholesalers can now have their answer in less than a minute using a smart phone,” he said.
To use the app, simply select the installation method and enter data for a quick material estimate. REHAU Radiant Calculator is available at http://radiantcalculator.rehau.com. Customers who require a project quote are encouraged to use REHAU LoopCAD® software or to request a radiant design from REHAU or one of the company’s channel partners.
For additional information on REHAU’s complete line of radiant heating solutions, contact: REHAU, 1501 Edwards Ferry Rd., N.E., Leesburg, Va., 20176. E-mail: rehau.mailbox@rehau.com. Web site: http://na.rehau.com/heating.
Wichita, Kan. — Viega announces two radiant training seminars in 2015 for design-build contractors and engineers. Viega, in collaboration with the Center for the Built Environment (CBE), at University of California, Berkeley, is holding the one-day training courses, titled, “Energy and Comfort Performance of Radiant Slab Systems.” The courses are co-presented by Fred Bauman, a Read more
Wichita, Kan. — Viega announces two radiant training seminars in 2015 for design-build contractors and engineers.
Viega, in collaboration with the Center for the Built Environment (CBE), at University of California, Berkeley, is holding the one-day training courses, titled, “Energy and Comfort Performance of Radiant Slab Systems.” The courses are co-presented by Fred Bauman, a prominent scientist at CBE, and Jason McKinnon, director of training, Viega.
Jason McKinnon
Viega recently announced a partnership with the CBE. Educating the industry on new and more efficient technologies for commercial integrated hydronics systems was one of the initial goals of the association between the two organizations.
The radiant training seminars are scheduled for May 13, 2015 in Washington D.C. and November 3, 2015 in San Francisco. The seminars will teach how radiant systems work, heat transfer fundamentals, energy use and thermal comfort in comparison to conventional all-air systems. Project examples and design guidance will also be covered.
“These radiant seminars provide a wealth of industry knowledge,” said Mark Parent, director of product management, Viega. “There is a lack of industry knowledge when it comes to radiant heating and cooling. Our hope is to help educate the industry on newer and more efficient technologies when designing commercial integrated hydronics systems.”
CBE is leading a research program on advanced integrated systems with a focus on radiant slab cooling, also known as thermally activated building systems (TABS). CBE recently accepted a $3 million grant over the next three years on radiant slab systems to research methods for optimizing radiant systems for energy efficiency and comfort.
Viega provides the most versatile radiant heating and cooling systems in the industry. Suitable for residential, commercial or industrial applications, Viega ProRadiant heating and cooling solutions include ViegaPEX™ Barrier tubing, Viega FostaPEX® tubing, Viega PEX Press fittings, manifolds, controls, mixing stations, sensors, mats, panels, tracks and plates.
For more information or to register for one of Viega’s radiant seminars, visit: Viega.us/training.
https://youtu.be/z8Yn7YcfbUk While real estate sales have improved across the country, growth has chiefly been seen in the mid-range market. Homes in the 1,200 to 2,500-square-foot range are spending less time with a realtor’s sign in the front yard. But new home construction has lagged, especially in the custom home business. Few people know this Read more
https://youtu.be/z8Yn7YcfbUk
While real estate sales have improved across the country, growth has chiefly been seen in the mid-range market. Homes in the 1,200 to 2,500-square-foot range are spending less time with a realtor’s sign in the front yard.
Jim Hedden owns George’s P&H, a company his father founded in 1959.
But new home construction has lagged, especially in the custom home business. Few people know this better than trade pros who provide the more luxurious options. In New Jersey, Jim Hedden is among those feeling the crunch.
“Most of our new construction business is in homes between 9,000 and 13,000 square feet, with a few towards 25,000,” said Hedden, who own George’s Plumbing and Heating Inc. His father started the company in Clinton, New Jersey in 1959. “That market slid hard in 2008 and hasn’t picked up recently, even though things are improving with the construction of average homes.”
Hedden uses a tekmar system to control lead-lag, multiple boiler applications.
But the company is still healthy, due in part to their widely varying residential retrofit work. Hedden also attributes their success to changes he’s made to become more competitive when those rare high-end jobs arise. “Any way I can shave expenses without sacrificing quality is a must,” said Hedden.
Controls add value
“Price point is definitely an important part of making a sale, but the other part of it — especially with the big homes — is what I can offer that other guys may not,” said Hedden. “Zone responsiveness and efficiency don’t often go hand in hand with a low installation price. There is firing efficiency, system efficiency and seasonal efficiency, to mention a few of the ‘efficiencies’. The price of installation and the effect it has on the price of maintenance need always be considered.”
Hedden has found that using indoor temperature feedback, as well as outdoor reset, is the ultimate combination for comfort and efficiency.
About two decades ago when radiant heat was re-emerging in the U.S., and long before broad use of condensing boilers was being discussed here, Hedden was among the many installers trying to find the best way to keep return temperatures above 140°F, thus eliminating the possibility of condensation within the traditional non-condensing boilers.
At the time, he used a tekmar-controlled variable speed injection pump (working like an automotive transmission) to both temper supply water going to the in-floor loops and change the water temperature in correlation to the outdoor air temperature (outdoor reset). Using a boiler’s thermistor to retain minimum water temperature, it made both high- and low-mass radiant systems work seamlessly with non-condensing boilers.
Hedden followed the evolution of the tekmar control system and is still using it today. In this post-mod-con, outdoor reset, indoor feedback world, he’s found almost limitless use for the controls – especially in the hi-end residential market he prefers to work in.
“Today’s ability to modulate a boiler down to supply a specific temperature changes the rules, as does variable speed injection pumping, but we still do some jobs that use proportional mixing valves for in-floor zones,” said Hedden. “But it’s not just about radiant anymore. We’ll use tekmar for virtually everything; commercial and residential.”
“Many control systems cater to — and do a great job — on specific space heating or DHW demands, but do not address the entire hydronic system,” said Hedden. “While managing multiple boilers [lead-lag and rotate], changing the boiler water temperature differential and synchronizing space heating zone ‘calls’ to reduce boiler firing cycles, as well as including outdoor air temperature reset tempered by indoor air temperature feedback — parallel shift of the reset curve — tekmar provides for a complete DHW and heating and cooling system package.”
“It can even vary the amount of priority time that DHW has over space heating zones depending on the outdoor ambient temperature,” Hedden continued. “If it’s especially cold outside, the DHW system might get only 10 minutes of priority.”
Still busy
“If keeping the trucks out on the job is the goal, there’s no substitute for being able to complete a variety of work,” continued Hedden. “Do it competitively, with good pricing and offerings that the next guy doesn’t have, and you’ll stay busy.”
One strange job that George’s P+H completed recently included a 450-sq.-ft. addition with radiant in-slab heating. Oddly, the boiler was a steam unit. Instead of telling the homeowner that he couldn’t keep his steam boiler and have in-floor heat — as three other mechanical professionals did — Hedden improved on an old trick he’d learned years before.
“We drilled and tapped the existing steam boiler below the water line, and pumped the hot water through a coil on a 40-gallon indirect tank,” explained Hedden. “A second circulator moved pressurized from the tank, through the floor.”
To assure that floor temperatures were optimal, he used a tekmar temperature differential controller with an outdoor sensor, and a sensor in the tank. The outdoor sensor acted as a reset. The two pumps act independently to provide the correct supply temperature and flow rate for the floor.
“We get creative when we need to, but we’ll stay busy regardless of the market,” said Hedden. So far, he’s right on both accounts.