RPA Tech Report: Smart and super-efficient
The kids are getting out of school, vacations are being planned and construction should be in full swing. Unfortunately, full swing today is not what it has been in prior years. New construction is down and there is still an overbuilt market with empty homes waiting for owners. Yet this year seems to be slightly better than the past four years.
The bright spots in residential construction are the replacement and remodel markets. With homeowners deciding to stay where they are, interest rates remaining at all-time lows and unemployment stabilizing a bit, many opportunities still exist to install green technologies such as high-efficiency heating systems.
An under-used opportunity for end users and the associated professionals involved in a project are utility rebates available in communities across the country. You can find a listing of utility rebates at http://energy.gov/savings. These are funds taken from every residential and commercial customer each month. These are the very incentives needed to upgrade old systems with new, high-efficiency equipment and systems. It’s your money, take advantage of it.
A comprehensive database of federal, state, local and utility incentives for installing renewable energy systems and energy-efficient equipment can be found at www.dsireusa.org.
Speaking of equipment, never in history has the United States had this amount of high-efficiency technology available in the marketplace!
Smart boilers, pumpsBoilers have become smarter, more flexible and super-efficient. The design issues of the first generation’s energy-efficient models have been massaged so they operate in a wider application base. The first-generation mod/con boilers suffered from flow-restricted design that produced a direct conflict between the stated efficiency and the true operating efficiency.
The first mod/con boilers that showed up on our shores were of a very low water content design. These boilers had a modulating burner design, but if the designer/installer did not perfectly match the lowest turndown point with the smallest amount of demand by the system, the boiler would short-cycle, causing a host of problems.
Beyond the most obvious issue - damage to the boiler from this cycling - those early high-efficiency boilers did not return the efficiencies that were expected. What was gained in thermal efficiency was lost in operational efficiency. The newest generation of boilers has begun to add more mass to the heat exchange, allowing for a wider use of the boiler in the high-efficiency, low-temperature systems of today.
It is a compromise between the “good ole” cast-iron unit that lasted for decades and the new condensing designs of today. These boilers are the perfect unit for multizone radiant and traditional hydronic systems.
Variable-speed pumps have finally taken hold in a wide variety of hydronic designs. Once only offered in commercial applications, the mini versions of their bigger brothers allow a number of options while at the same time operate far more efficiently than ever before. These pumps, in conjunction with the new medium-mass condensing boilers, offer endless new design possibilities.
These new smart pumps have come to market because of a demand in the market. In the past we would see dozens of small circulators handling each zone of a radiant system. Though an impressive system if installed correctly, it was very expensive to operate and eventually service.
Modern systems now allow for a single pump modulating through its pump curve, matching its flow based on the demand in the system. Quiet operation, energy efficiency, a smaller piping system and an overall lower installed cost make these new pumps a perfect addition to today’s hydronic systems.
These are just two of the overall components in a modern hydronic system. And though they have been out for a while now, they are just starting to be recognized for their flexibility in a wider variety of installation designs, resulting in a simplified and more competitive hydronic/radiant package for home and business owners.
Showcase your radiant workYou may know that the Radiant Professionals Alliance conducts a competition each year that recognizes exemplary effort and hard work within the industry - the System Design Showcase. If you are an RPA member, I encourage you to consider submitting one of your projects this year in one or more of six different categories. Your peers will perform private, structured judging via a secure “members-only” section of the RPA website.
Winners are to be announced at the RPA’s Annual System Design Showcase Reception, Sept. 18, in Chicago during the RPA’s Annual Membership Meeting and Conference.
I am looking forward to seeing the innovative and exceptional radiant projects our members have installed. Whether simple, complex, new or retrofit, we hope you will share them.