• Tag Archives Hydronic
  • NOW A TRUE DELTA-T ECM HYDRONIC (FHW) HEATING APPLIANCE!

    Hydronic (FHW) heating system installations can be likened to creating something with a giant Erector Set™. As a kid, mine came with an electric motor enabling powered cars, airplanes, ferris wheels, etc. Days, weeks and months of childhood imagination and expression ensued. Great memories!

    Now as “big kids” hydronic heating system installations offer us a similar fulfillment of free expression. Within the limits of ultimate system functionality hydronic “artists” can seemingly paint their own canvas while getting paid for it! The question logically arises however as to where are the cost benefits of our efforts? We argue that heating guys are indeed losing direction, both technically and functionally. The adage “Old Dogs need to learn New Tricks” comes immediately to mind, regretfully also being one. It’s not only our innate trade resistance to change but not to think forward in applying what has preceded us ….. beginning with Physics 101!

    Gravity convection was the means of distributing heating water from the Roman Age onward. From the mid-1800’s to about 1930 it was “Queen” Gravity Hot Water along with “King” Steam. However gravity hot water systems required large boilers, piping and radiation sizes. They were slow to react, single-zoned and fuel hungry, whether burning wool, coal, oil or whatever.

    Introduction of the electric circulating pump changed hot water (hydronic) heating forever. Now multiple zones, rapid response through less intrusive radiation and powered burners do it all very conveniently. Gravity is still there, but we have necessarily learned to control it with flow check valves. Apart from the brief and unsuccessful introduction by American Standard of their “Ash Can” Gravity Boiler System in the late 1950’s (our nickname – we were Am-Std Installers back then) FHW has predominated. Circulators began by being placed on the (cooler) returns with flow checks on the (warmer) supplies to control convection. Then circulators moved to the supplies along with the valves. Boilers are now migrating from two-pass to three-pass or condensing types for greater efficiency. That’s arguably been it ….. until now!

    Enter the Delta-T (differential temperature) sensing and managing, ECM (electronic commutator motor) driven Variable Speed Circulator, specifically the Taco® VT2218-HY1-FC1A01 (Current Model). This latest iteration in Taco® Hydronic Distribution Technology is making its inevitable mark on radiant and other hydronic circuits. Its “smart” capabilities are many however, having five (5) selectable operating modes, but we are focused only upon the “DELTA-T MODE” within its appetizing menu.

    We have been experimenting for some years now with Taco®’s prior Delta-T’s and the current VT2218 ECM as a dedicated system circulator, beyond that denoted in Taco®’s Product Brochure. During this process we discovered and integrated differential temperature management with natural hydronic convection (gravity) for an optimized design with superlative results, again well beyond those claimed by Taco®. Multiple “Beta Site” installations have provided us with sufficient data and results to seek “Provisional” and now subsequent “Non-Provisional Intelligent Property Protection” on our:

    ENHANCED CONVECTION, DIFFERENTIAL TEMPERATURE MANAGED HYDRONIC HEATING APPLIANCE (Patents Pending, USA & Canada)

    Quite a mouthful indeed, but place the emphasis on APPLIANCE. You see, delta-t hydronic technology is not merely a “circulator swap” for radiation and energy efficiency gains. It offers additional opportunities in hydronic process integration and management as yet either unrecognized or underutilized. Our efforts fall on the latter, particularly when cooperating with “Mother Nature” by employing natural hydronic (gravity) convection to an operational advantage.

    Falling back upon and employing the principles of “non-powered” gravity heating we optimized a “contemporary” Delta-T ECM FHW System. Utilizing supply and return iron-piping “stacks” and compacted manifolding minimized distribution head losses. Combine these with the thermal storage capacity of mating to a cast-iron high-mass boiler enables a true, free-standing APPLIANCE. Its profile is contained within the boiler footprint plus about a foot of exhausting & piping space to the rear. Modular construction is a natural for hydronic elements as well as system wiring and controls. Module variations to suit particular site and application requirements logically follow.

    Taco® promotes energy reductions of up to 85% and 15% for electricity and fuel respectively by using their Delta-T ECM Circulator Product. We emphatically agree ….. and even more! Measurements on our multiple “Beta Sites” indicated a deviation that was not anticipated. Namely, upon the dedicated VT2218 system circulator achieving preset “delta-t” and stabilizing, the wattage displayed further deteriorated to approximately half this value along with some further speed reduction! A subsequent “Beta Site” circulator failure confirmed our suspicions. First, that failure event was not noticed for an estimated 2-3 days, and then only with a gradual decay in house temperature. The event was camouflaged by an integral Indirect Water Heater (IWH) based domestic hot water (DHW) delivery that was never affected!

    The circulator failure not only quantified the now measurable convection (gravity) heating effect witnessed, but qualified our overall near-boiler piping configuration, purposely designed with a de facto priority circuit for the IWH Option. The latter eliminates the need for that particular optional control feature. Further witnessed on our “Beta” circulator failure was boiler temperature operating near maximum. The Hydrolevel® 3250-Plus Aquastat on our Weil-McLain® UO Boiler logically incremented system temperature upward, attempting to satisfy prolonged zone demand(s). The higher supply/return temperatures and differentials further enhanced convection. The effective 700 pound plus thermal storage mass of our “appliance” also served to dampen the close-coupled IWH zone demands! It is reasonable to presume that the IWH thermal storage would also be “pumped down” during a burner failure, passively prolonging thermal decay.

    Radiation configuration and piping integrity are paramount to convection (gravity) heating effectiveness however. Drawing from over 40 years operation of our personal dual-fuel, fully no-power emergency capable hydronic heating system, we can attest to radiation attribute importance. Simple, well designed serial and split baseboard loops work best. De-aeration is absolutely necessary and system water pressure must be present. Taco® Zone Sentry Valves utilized in our design have a manual open-close feature that can be utilized to regain a heating level upon an actuator failure, as do current flow check valves. (NOTE: You can replace a failed Taco® actuator head on our appliance in 20 seconds – if ever a need!)

    Complimenting hydronic performance is our “Compact Steel Hydronic Header” (Patents Pending) that positions, orients and provides flexibility in both zone and return valve mounting with expansion capability. Placing Taco® Zone Sentries at their minimum (2-3/4″) spacing with wired harnessing eliminates the need of a significant valve or circulator relay expense ….. and with greater diagnostic and system functionality!

    Currently applying our manufacturing process expertise we are projecting the “economies of scale” provided in our construction. The physical modules of boiler, supply and return are configured for capacity/fuel and zone complement and inventoried. A natural and complimentary option of an Indirect Water Heater (IWH) for domestic hot water (DHW) generation falls into this methodology as well. Adding assembly fixtures, applied tools, wiring assy’s, etc. further contribute to appliance value.

    A Hydronic Heating “Appliance” changes everything. The historical loose-piece “process” of hydronic (FHW) installation now becomes a “product” installation of lesser content with higher, predictable system performance and costs. Not just having a stock product that readily configures to the specific requirement, but being available on demand to fulfill both routine and seasonal emergency failures is a valuable resource indeed. Appliance costs and performance are also guaranteed, with all components warranted by their U.S. Manufacturer(s) as with any contemporary installation.

    Our motto: “Simple, Durable and Efficient FHW Heating ….. Period!” sums it all up. Technology has finally caught up with hydronic heating, and it’s about time! The end game after all is providing real value to the consumer, is it not?

    Author’s Note: Updated 01/20/2018


  • SUBMISSION FOR NON-PROVISIONAL (UTILITY) PATENT PROTECTION

    BoilersOnDemand.com via its Principal, Paul D, Mercier, Sr., has filed for Non-Provisional Intelligent Property Protection (Utility Patent) in the United States of America and Canada on the: ENHANCED CONVECTION, DIFFERENTIAL TEMPERATURE MANAGED, HYDRONIC HEATING APPLIANCE.

    We deem this to be the first, truly integrated, free-standing, simple, durable Hydronic (FHW) Heating Appliance in the Market. Enabled by recent advances in Delta-T ECM Hydronic Distribution, the major elements of energy generation and distribution augmented by our optimization of natural convection (Gravity Heating) comprise the highest efficiency product available ….. bar none!

    A true “appliance”, merely coupling it to site utilities and radiation effects a completed hydronic (FHW) heating installation. Dramatic reductions in materials, labor & skill content, floor-space and maintenance have been realized. A truly “Value Engineered” product.

    Further detail will be made available on our web site www.BoilersOnDemand.com as we finalize our patenting process.


  • DELTA-T ECM HYDRONICS – Redefining “The Plumber’s Playground”

    Hydronic heating comprises warming water as a medium, moving and expending its energy to warm an environment. Thus we have boilers as heat generators and radiation to convert heated water into warmth. Between these we must distribute our medium via pipes, pumps, valves and controls to meet heating demands.

    Basic hydronic system design rules of course must apply, but by and large the final product interpretation has been left to the tradesman/installer. This individualization provides a very attractive latitude of self-expression. Like an artist painting on a new canvas individual skills, styling and practice all comprise the final “picture”, with the author’s “signature” applied. Based upon our field observations we have come to refer to hydronic distribution in particular as “The Plumber’s Playground”, and with no apologies offered.

    Unfortunately the Laws of Physics apply equally to hydronic system installations as to any other enterprise. Therefore that maze of pipes, valves, circulators, controls and wiring evidenced in a “plumbers playground”, no matter how pretty, daunting or impressive is unnecessarily complex, costly and under-performs. In fact any system installed within the past three years or more not employing Delta-T ECM Hydronic Distribution Technology specifically is woefully under-performing!

    The Heating Game has changed, led by the Taco® Delta-T ECM VT2218 Hydronic Circulator and its supporting Taco® Zone Sentry Valves. We refer to it as “The Hydronic Revolution”, as it truly is! These two (2) devices, properly applied, can and do dramatically simplify the complexity and content of a conventional hydronic heating system. Again, properly applied and supported by contemporary control systems provided by an “Intelligent” System Aquastat with idealized piping (plumbing) can further enhance performance, as our work has evidenced. Our development efforts and observations are reflected within the remainder of this presentation.

    The Delta-T ECM Variable Speed, Intelligent, Multi-Temperature-Sensing Circulator is a marvel of applied technology. Its ability to sense, measure and maintain a preset temperature differential in a hydronic circuit virtually optimizes heat transfer efficiency in a single, automatic step. Further being able to accommodate varying demands from multiple zones (circuits) virtually seamlessly as we have evidenced places it as the heart of any hydronic system. Using an automotive analogy we slogan that we are putting an ‘Automatic Transmission’ on a Boiler, but doing it hydronically.

    Now pair this Taco® Delta-T ECM Circulator with a compliment of their Zone Sentry® Zone Valves and you dramatically reduce energy consumption while gaining some further fuel efficiency. As Taco® promotes we are seeing distribution power consumption drops to 11-13 watts and in another instance to 8 watts during normal operation! Compare these with 80 watts for a single Taco® 007 and 21 watts each  for a Heat Motor Zone Valve. (The Zone Sentry® uses 11 watts, and then only in a brief actuator “charging cycle”.) Hydronic heating system power consumption is virtually never considered in design, but it should and furthermore must be!

    Piping is the pride of any plumber (ourselves included) yet in so being can become a detriment to system performance. To this point we offer that hydronic convection (the natural attribute of heated water to rise, and cooler fall) is not considered as a positive contribution to system performance, but an attribute to be controlled. As we have witnessed in our design effort however, natural convection is a measurable asset, particularly when configuring piping and placement to maximize its effect. Near-boiler piping, to employ the trade term, is crucial to maximizing hydronic performance. Compacted packaging of correct pipe sizing and layout close to the boiler displays great natural (non-powered) circulation that may not only supplement but also heat at reduced levels. We had an early Delta-T Circulator failure on one of our “beta” installations that was not discovered for an estimated 2-3 days! How’s that for convection — like “paddling your canoe with the current”.

    When you fully integrate the “intelligent” Delta-T ECM Circulator, Zone Valves and Aquastat with idealized convection you come to the conclusion that hydronic system installation is no longer a process, but functionally becomes an Appliance. Our resultant “package” is contained within its boiler footprint plus minimal rear piping space. A designer need only define system capacity, number of zones, fuel type and exhausting to define the “appliance”. Further, the application lends itself to modularization, and thus to versatility by default. Not only do we significantly reduce the material content of a system, but its labor content and installation time as well.

    Now there is both a trade and consumer option, a virtual Hydronic Heating Appliance with a fixed cost and defined, superlative performance. Our work to date has been developing a “Package Delta-T ECM Hydronic (Oil) Heating System” that achieves its higher performance by incorporating Delta-T ECM Hydronic Distribution Technology with a high-mass, lower operating temperature boiler for optimized performance. But also recognize that Delta-T ECM Circulation will work on any fueled hydronic application, putting an “automatic transmission” on ANY boiler. This obviously reduces the size, content and complexity of the “Plumber’s Playground”, but to a net performance advantage in doing so.

    To summarize, a “Hydronic Heating Appliance” is in our near future, defined by technology and necessitated by the market, like it or not. Its Performance Specification will virtually determine system performance, unlike the potpourri of present practice. Our publicized contributions are documented on our website www.BoilersOnDemand.com.  Please note that our current and following product offerings are under Intelligent Property Protection (Patent Pending). We look forward to “Boilers On Demand” in the new “Plumber’s Playground”.


  • “DELTA-T (ΔT) ECM HYDRONIC HEATING 101” PRESENTATION AVAILABLE

    We have formulated and make available a Power Point Presentation entitled “DELTA-T (ΔT) ECM HYDRONIC HEATING 101”.

    It details our development and application of the Taco® VT2218 Circulator as a Dedicated System Circulator creating a “Packaged Delta-T ECM Hydronic (FHW) Heating System” (Patent Pending).

    Contact us for additional details and arrangements.

    603-588-2333 or info@boilersondemand.com

     


  • DELTA-T ECM HYDRONIC DISTRIBUTION – Really “Raising The Bar”!

    Heating and moving water (hydronics) is recognized as the most efficient method of creating and distributing warming energy. From the Roman Baths to Gravity Piped Hot Water Systems of a century ago natural convection of heated water provided a simple, if seemingly temperamental solution.

    Adding pumps (circulators) to heating water distribution has forever improved comfort an flexibility. However, their application has been less than ideal, utilizing only fixed-speed/capacity circulators, typically poorly applied to residential heating in particular. Using a “one size fits all” approach and swapping sizes to effect results has been a thorn to the trade suppliers.

    Applying switchable, multi-speed circulators has provided an interim solution to poor matching options. Further, measuring actual circulator zone supply and return temperature differentials with an infrared thermometer while selecting speed(s) has provided a more efficient solution. It’s still a less-than-ideal result, with a cost premium.

    The Delta-T (Differential Temperature Sensing) Variable Speed Circulator has been around for some years now, providing the idealized solution to heating distribution flow management. It has arguably fallen far short of its potential, burdened by high initial cost, audible operational “whine” and low speed “growling”. Occasional high load torque stalls further contributed to its unknown nature.

    Enter the ECM (Electronically Commutated Motor), the latest iteration of the “intelligent” Delta-T Variable Speed Circulator. The “heir apparent” is whisper quiet yet powerful, dramatically reduces power consumption with no “torque stalls”, displays great functional data and at a palatable cost. Taco® Comfort Solutions of Cranston, RI also claims up to 15% fuel savings along with an 85% energy drop with their 00e Series VT2218 ECM Circulator, pictured.

    Author’s Note: We former High-Tech Process Engineers were applying “Stepper Motors”, the ECM predecessors to Machine & Process Control over 40 years ago. Finally, the Heating World is getting some real tools to work with!

    The Delta-T Circulator is and has always been marketed as an enhanced replacement for a fixed or multi-speed circulator. Have a zone performance issue? Substitute a Delta-T and “tweak” it in. Problem fixed, within the constraints of the zone design and a 3X cost premium of course. This latest (and supplier exclusive) Taco® VT2218 is being very well received, breaking the “Cost-Performance Stigma” of its predecessors and counterparts. We love it!

    VT2218+ZV ultra-oil-1 HTPSuperstor

    As “High-Tech” Process and Manufacturing Engineers with a Heating Discipline we (Mercier Engineering) have further projected the Taco® Delta-T ECM VT2218 as a Dedicated System Circulator, the acknowledged INDUSTRY FIRST to do so! Reviewing its Technical Specifications the VT2218 is ideally suited to residential/light-commercial heating system applications, given that operational attributes can be accommodated. These are namely:

    1. Providing uniform heating performance under normal multi-zone demands.
    2. Simultaneously servicing an Indirect Water Heater (IWH) to optimize both domestic hot water (DWH) and heating water generation.
    3. Prioritizing DHW generation within varying area heating demands.
    4. Accommodating differential temperature branching such as radiant zone(s).
    5. Satisfying both current and future (planned expansion) demands without an efficiency penalty.
    6. Providing beneficial System Service & Reliability projections.

    Over the past fifty (50) years we have installed and monitored “conventional” hydronic (FHW) heating systems, focusing on component selections, their performance and service levels. This continual qualification process has yielded a set of Premium American Components with “zero-fail” histories, at the expense of other NAFTA, Euro & Chinese products.

    Recognizing the potential of Delta-T Hydronics Distribution as previously noted, about five (5) years ago began a concerted effort to select and qualify the dedicated system circulator application. Our independent work using three (3) successive iterations of Taco® VDT, HEC and VT/00e Products has yielded not only a viable, but a superlative Packaged Delta-T ECM Hydronic Heating Appliance™. Its performance is principally based on our Proprietary Near-Boiler Piping System that constitutes the basis of our Non-Provisional Intellectual Property Protection Submission (Patents Pending – USA & Canada).

    So what began as an “evolutionary” effort to apply a newly available “tool” in the resultant has approached a “revolutionary” one. Our Packaged Delta-T ECM Hydronic Heating System™ is actually a FHW Heating Appliance, an industry first! Placing the Delta-T ECM Circulator into a full hydronic (FHW) heating system we slogan as “Putting an ‘Automatic Transmission’ on a Boiler”. Coupling “intelligent” Taco Zone Sentry® valving (pictured), a “high-mass” boiler (Weil-McLain UO – pictured) and an integrated IWH (HTP SSU45 – pictured) dramatically reduce complexity and idealize hydronic system performance.

    In our introduction we referenced the “natural convection” (gravity heating) used by the Romans, et al that prefaced our “modern” hydronics. Our optimized Delta-T ECM System exhibits exceptional gravity convection qualities, continuing heating upon circulator disablement or with zone valve manual operation. Short of a full electrical outage significant gravity convection heating continues, providing a useful fail-safe protection feature.

    Now let us really “Raise The Bar”. Here is performance data taken from two (2) similar “beta test sites” in our grouping.

    100,000 BTUH System, Oil-Fired, 3-Heating Zones + IWH

    Attribute “Conventional” System Delta-T Hydronic System Comments
    System Efficiency (Est.) 87% (Boiler Only) 90++% (Aggregate) Combined Hydronic Efficiencies
    Mean Operating Temperature > 145°F (Est.) 132-140°F (Observed) Normal Heating Operation
    Distribution Power 165 Watts (Est.) 11-12 Watts (Observed) Equates to Taco® Claims
    Distribution Fuel Efficiency  N/A – 15% Consumption Per Taco® Claims
    Natural Convection  Minimal to Moderate Very Significant (Observed) Very Installation Dependent
    System Footprint < 35 Sq. Ft. 12 Sq. Ft. (Actual) Very Installation Dependent
    Construction/Life Low-Mass C.I. or Stl. + Copper High-Mass C.I. & Stl. Only  10 to 20 vs. 30+ Yrs. (Est.)
    Complexity/Maintenance/Skill Higher/Annual/Specialized Low/Bi-Annual/Standard Standard Controls Only
    System Installed Cost (Est.) $10,000+ (Est.) $7,500 (Quoted) Southern NH Region

    This is the new “Bar Height”.

    We challenge ANY Tradesman or System Installer to raise it.

    To Summarize:

    1. Delta-T ECM Hydronic Distribution is singly the most significant and cost-effective contemporary heating advancement.
    2. This technology is applicable to any fueled hydronic heating system with substantial packaging and cost benefits.
    3. System configuration using a Dedicated Delta-T ECM Circulator further reduces physical and technical complexity while idealizing hydronic performance.
    4. Our Packaged Delta-T ECM Hydronic Heating System™ is the first, true Hydronic Heating Appliance, considering its intrinsic architecture, performance and as-installed economics.
    5. This is the new Standard of Measure in Hydronic Heating.

    Author’s Note: Updated 06/12/2017


  • THE DELTA-T ECM CIRCULATOR — The “Automatic Transmission” for Boilers

    After speaking on-site  with a local customer about his system, he inquired as to what else we were doing. A mistake on his part.

    Both of us having differing technical backgrounds I launched into an inspired dissertation of our application of Delta-T ECM Circulation to Residential FHW Heating Systems. Obviously very interested, a running Q & A exchange of increasing technical depth ensued to the point of my noting he was developing that “deer in the headlights” look of incomplete understanding.

    We engineering types have a terrible habit of technically overloading our audiences, not as an “ego-trip”, but to inform as effectively as possible — we think!

    Needing to salvage the situation I paused, desperately searching for that inspired “bolt of lightening” to strike and clarify the atmosphere. By seeming grace, it came immediately! “I’m putting Automatic Transmissions on Boilers.” Yeah”, he responded, “that makes complete sense. Good idea!” Our further conversation became an analogy of FHW Heating Systems to Automobiles, surprisingly clearing our technical disparages. To expound …..

    After all, hot water boilers and automobile engines are both truly “heat engines”. An automobile engine must convert as much fuel combustion energy into mechanical propulsion power as possible via pistons, crankshafts, etc. Less than 60% becomes useful power, the remainder is dissipated as waste heat. The hot water boiler on the other hand necessarily converts its fuel combustion energy directly into useful heat at up to 97% efficiency!

    The automobile uses a transmission to adapt its mechanical power to control vehicle propulsion. A variety of gears, pumps, valves, etc. are used to accomplish this. The hot water boiler conversely needs only to move heated water (via a pump) exactingly to ideally acclimate our heated areas and (optionally) our domestic hot water (DHW).

    The Delta-T ECM (Differential Temperature) Variable Speed Circulator (Pump) is that ideal “boiler transmission” that delivers heated water most efficiently to maintain our comfort. So efficiently does it do so as to reduce system fuel consumption by up to 15% and electrical consumption by up to 85% as documented by Taco, Inc. Published Testing Results.

    No longer is heating system efficiency measured solely (and inaccurately) by the Boiler AFUE (Annual Fuel Utilization Efficiency) Rating, but the aggregate of Boiler, Distribution and Radiation Efficiencies. There are THREE (3) Elements in a hydronic heating system! Just as in Sulky Racing, it’s the combination of the horse, the jockey and the buggy that wins races.

    Even more exciting  is the opportunity provided by the Delta-T ECM Circulator to most efficiently configure a FHW Heating System, which we have done very effectively. Refer to our other, recently published Delta-T Blogs on this site that detail our development, field testing and observations of our systems.

    Our “Packaged Delta-T ECM Hydronic Heating Appliance™” (Patents Pending) exhibits the following attributes in direct comparison to the typical “conventionally installed” system:

    1. Has a higher Combined Boiler AFUE and Delta-T ECM Distribution (System) Efficiency than achievable with any “conventional” system configuration.
    2. Consumes less fuel and electrical power than any equivalently sized system.
    3. Our Integrated Boiler/Indirect Water Heater System occupies 1/3 to 1/2 the floor-space of others.
    4. Our proprietary Fully-Iron & Cast near-boiler piping maximizes durability and distribution performance using fewer materials.
    5. Further combining a High-Mass Boiler with an All-Stainless Indirect Water Heater assures a dramatically projected economic life (30 years or more?).
    6. A truly universal, multi-fuelable Appliance. Just change the burner and not the system!
    7. Provides, Simple, Durable, Efficient and Cost-Effective FHW Heating.

    So yes, we do put “Automatic Transmissions” on Boilers!

    Author’s Note: Updated 07/23/2018


  • BEYOND AFUE’S – TOWARD REAL HYDRONIC (FHW) HEATING EFFICIENCY!

    For the past year Mercier Engineering has been immersed in developing and preparing for market it’s Packaged Delta-T Hydronic (FHW) Heating System™, based on our past heating experience projected into the new world of “Delta-T Circulation”. You may have noted our preoccupation with this technology in “The Heating Blog” on our www.boilersondemand.com  website. Time to “put our money where our mouth is”, so to speak. The results of our efforts we deem noteworthy and are initially reflected in this writing.

    As the titling of this blog purposely implies, we must get beyond weighing hydronic heating system efficiencies solely upon the boiler’s Annual Fuel Utilization Efficiency (AFUE) Rating.  It is only one of multiple elements in an operational formulation that is seldom if ever approached, even more poorly understood, and we allege almost universally misapplied. Strong words which must be tempered by the reality that there has been little market incentive to change our approach to serving the residential FHW heating market in particular; but we ultimately must adapt and change it for the consumer’s benefit.

    AFUE is a regulatory, laboratory testing procedure intended to establish an efficiency value for a hydronic (hot water generating) boiler under a defined operating sequence and conditions. It can be presumed that it executes this comparison very effectively, under its terms. However, what it does not measure from our observations is in practice very significant. Specifically these Non-AFUE Test Attributes are:

    1. There are no provisions for qualifying or measuring between-cycle “stand-by” or “idle-time” losses. This is the time between burner firing cycles when the boiler is prone to radiated energy and convective exhaust (flue) losses, presumed to be non-productive.
    2. Similarly, the testing is “steady-state” in execution, providing no qualification or quantification of individual boiler attributes that may contribute to site application efficiency.

    These test attribute observations have been borne out in field applications, where system performances have not correlated well, boiler-to-boiler or system-to-system. To further complicate this is the variability of physicals to each application, however subtle. The forums and blog sites are rife with these seemingly “apples-to-oranges” commentaries. Our developmental efforts may be able to provide some explanations.

    From our observations there are necessarily five (5) elements contributing to total system energy efficiency:

    1. The boiler (heat engine) energy conversion efficiency or AFUE.
    2. The physical attributes of the specific boiler complimentary to system operation.
    3. The energy required to move heated water through the distribution system (radiation).
    4. The effective matching of radiation elements to heating demand.
    5. The control algorithm(s) to match energy creation with varying system demands.

    Our initial efforts have been with oil-fired hydronic systems and is the focus of this document, with gas-fired and solid-fuel applications to follow as resources permit. However, much of this effort is applicable as the basis of other heating systems.

    Varying the output (energy creation rate) of any heating resource is paramount. This has been readily achieved in gas-fired boilers by “modulating” combustion with sophisticated valving and controls. Typically they adjust from 20 to 100% of capacity, from “idle” to “full speed” to use the automotive analogy. However, direct modulation of oil-fired systems is not feasible using current technologies. A fixed (capacity) firing rate via pressurized, nozzle induced fuel atomization is the norm. Therefore, the only option is to adjust the operating temperature of an oil-fired hydronic boiler via controls to compliment heating demand. This is reasonably well-managed with modern “cold-start” aquastats, external temperature sensors, etc.

    The prior unaddressed penalty to particularly residential hydronic systems has been the toll on equipment and electrical energy requirements of circulating heating water with fixed-speed circulators. They are notoriously and arguably universally misapplied and inefficient in practice. Reducing water temperatures merely aggravates the situation by prolonging circulator cycling.

    Fortunately technology has come to the rescue in the form of the “Delta-T” Circulator, now becoming very applicable and affordable to the residential/light commercial markets. The undisputed pioneer and flag-bearer in this market is the Taco Viridian VT2218 found at this link: http://flopro.taco-hvac.com/media/Viridian_VT2218_100-114.pdf  To use the quote “This changes everything” is not an exaggeration! The Viridian is in fact the second generation, replacing the entry product Taco “BumbleBee” found at this link: http://www.taco-hvac.com/uploads/FileLibrary/100-101.pdf We mention the “BumbleBee” only because it has rapidly become a “cult product” in the HVAC Community, somewhat akin to the “Trekkies”. It was our initial “new tool” in developing and thence refining our product(s). Like our brothers, we hate to see it go as we move to the refined and more sophisticated “Viridian”.

    Referring back to our five (5) elements to total system efficiency, Delta-T Circulation is number three (3) on the list but is deservedly and necessarily the foundation of any hydronic system improvement. Taco reports system Delta-T Circulator-only swaps yielding 15% fuel usage reductions. It is the keystone of our Packaged Delta-T Hydronic (FHW) Heating System™, and should be the first improvement to any system! We caution however that this will require substantial near-boiler system re-piping and your installer must be knowledgeable. It is discouraging to note how few of our fellow tradesmen are cognizant of Delta-T or have used it beyond a radiant heat loop. We “Old Dogs must learn new tricks”, and we have!

    The second element of import is the necessity to employ “Cold-Start” Boiler/Aquastat Hydronic Technology, which overlaps Nos. 2 and 5 in our list. We are unabashed in our praise of the Hydrolevel 3250-Plus “Fuel Smart” Aquastat, found at this link: http://www.hydrolevel.com/new/images/literature/sales_sheets/fuel_smart_hydrostat_sales_sheet.pdf   It is now standard equipment on all our Weil-McLain Ultra Oil Boilers, and none too soon! The inter-action of the 3250-Plus with the VT2218 Circulator’s operational software is paramount to total system performance, as we have learned.

    Note: “Cold-Start” Technology applies to “heat-only” boilers. DHW (Domestic Hot Water) must be effected by an external Indirect Water Heater or another dedicated appliance. We combine the Indirect Water Heater in our design for optimized Heat and DHW Generation.

    Element 3: Our development indicates individual boiler attributes are significant. Specifically,

    1. Boiler supply and return tap placements are crucial to system “packaging”, i.e. the ability to compactly (efficiently) structure near-boiler piping. (We can pipe into a space as close as 11″ from the chimney, with all piping and controls behind the boiler, yet readily accessible.)
    2. A very high boiler mass (weight) for its capacity, i.e. for both thermal damping and storage.
    3. Favorable exchanger flue passage routing and exhausting.
    4. Burner type to compliment its attributes.

    The noted attributes lead us to our “Boiler-of-Choice”, the Weil-McLain Ultra Oil Series with the Beckett NX Burner. Refer to this link for detail: http://www.weil-mclain.com/en/assets/pdf/Ultra%20Oil%20Brochure_8%20Pg_web1.pdf   We have had “conventional” system design and installation experience with this boiler for over ten years now, with only one “no heat” service call, a failed aquastat. Weil-McLain has since upgraded it to the Hydrolevel 3250-Plus, thank God!

    The Beckett NX Burner has been likewise flawless in operation. Literally a “plug and play”. Its dual vent typing capability (direct & chimney) has proven beneficial to problematic venting applications, especially when encountering “cold chimneys” in our northern climate. Fully exposed exterior chimneys are sure to give a rough startup without utilizing its pre-purging and pressure firing features.

    The key attribute to system performance outside of Delta-T Distribution has proven to be Thermal Mass (Storage) provided by the sheer robustness (weight) of the Weil-McLain UO Series High-Mass, Triple-Pass Boilers. They are “The Heavyweight Champions” by far and as a result exhibit lower mean boiler operating temperatures and very less frequent burner cycling.

    As a matter of policy we do not cite or criticize our competitors, but we must make a single attribute comparison to emphasize our point. The approximate block weights of the top hydronic (approx. 100KBTUH, 87% AFUE) oil boilers are:

    Manufacturer/ModelApprox. Ship Wt.
    less Tare (lbs.)
    % of HighestComments
    Buderus G115/G21537560%Adjusted for 100KBTUH
    Burnham MPO-IQ11545072%
    Weil-McLain UO-3625100%

    Author Note: Very noteworthy, the Weil-McLain is also disproportionately the lowest cost per pound (by nearly half) of the three. Just what is the consumer paying for, we wonder?

    Radiation (Element 4) efficiency is the remaining, but least controllable variable in a heating system. It is substantially outside the scope of our system application, yet there are some performance elements we can address.

    Existing hydronic radiation:

    1. Removal of unnecessary valving in zone supplies and returns. All zone control functions are integrated into our system package.
    2. Zone interconnections can be optimized by correct pipe sizing and routing. It confounds us as to why some plumbers use virtually no 45° fittings! You can use 3-4 of them vs. a 90° elbow for the same flow resistance, and you use only 70% of the pipe required for a 90° elbow routing.

    New hydronic radiation:

    The contemporary approach to radiation varies widely, from simple radiation loop(s) for zoned heated areas to individually heated rooms throughout. The more finite the control, the more piping, fittings and control valving, and the more hydronic distribution energy is required.

    Ironically, the same Delta-T Circulator Technology we employ to maximize our system performance has preceded us and become the darling in particularly radiant system applications. We have also employed them in these and they perform admirably. They reduce the energy requirements significantly but yet still camouflage the basic issue.

    If your concern is total energy consumption of a system, we would invite you to consider using less sophisticated radiation distribution schemes. A properly designed, installed and balanced series or split piping loop exudes simplicity and will likely be a lower installed cost. The KISS Principle applies — keep it simple ….. (Refer to our Heating Blog Library for additional detail.)

    To Summarize:

    1. Additional Boiler Attributes are important, beyond the AFUE Rating. In particular heat exchanger thermal mass (weight) will lengthen service life while minimizing repair costs. Burner attributes related to exhausting and tuning must also be considered.
    2. Delta-T Hydronic Distribution Technology is the key to improving any system’s energy performance, both for heating fuel and electrical power consumption.
    3. Inter-related “intelligent” controls determine system operational performance. They are currently the Hydrolevel 3250-Plus Boiler Aquastat and the Taco VT2218 Delta-T Circulator Logic.
    4. Near-boiler plumbing in particular affects system performance. This is maximized in our system piping configuration to include fail-safe “gravity convection”.
    5. Interconnection between our system zone access points and the existing must be executed with the goal of minimizing flow anomalies.
    6. Existing and/or new radiation installations must likewise be executed by idealizing flow conditions inasmuch as possible.

    References:
    We strongly recommend referring to Taco’s website: http://flopro.taco-hvac.com/deltat_resources.html and refer to the various Delta-T resources therein. There’s a volume of resources here that will properly inform you of this new technology and its place in your Hydronic (FHW) Heating System.

    Author’s Note: Hyperlinks updated 08/22/2017


  • WHAT IS A DELTA-T SYSTEM?

    A Forced Hot Water (FHW) Heating System is designed to efficiently provide energy distribution to heated areas. This is accomplished by combusting fuel in a boiler and moving the heated water through radiation to warm the desired environment.

    However, to accomplish this most efficiently requires:

    1. A high-efficiency appropriately sized and fired boiler.
    2. Properly proportioned and positioned radiation for each heated area.
    3. Idealized, simultaneous energy delivery of heated water to all radiation, irrespective of heating demand patterns.

    Practically however, none of these elements are absolutely correct, nor can they be. Boilers and radiation are almost never idealized for efficiency, but the third (energy distribution) is typically the most poorly executed of all. You must deliver heated water at an ideal rate for maximum heating transfer efficiency.

    Common distribution systems typically consist of:

    1. Dedicated circulators for each zone, or
    2. A common circulator with a zone valve for each zone.

    These configurations do not perform efficiently in practice, and in particular zone valves.

    “Delta-T” is a technical connotation. “Delta” (from the Greek letter ∆) is difference, or differential. “T” designates temperature. Thus Delta-T (∆T) is “differential temperature”.

    The Delta-T Continuously Variable Speed Circulator  employs temperature sensors attached to the boiler supply and returns points. It measures and maintains the ideal temperature differential by infinitely adjusting its water delivery rate (pump speed) to suit. Coupling with the new Low Energy, High Flow Zone Valves this technology maximizes the efficiency of any hydronic system with dramatically reduced electrical power consumption.

    VT2218+ZV

    Additionally, this system also smooths the performance of your existing radiation by typically eliminating hydronic whistle from over-sped, heating lag and imbalance from under-sped zones.

    No costly control system is necessary! The innate intelligence of the Delta-T Circulator teamed with the self-diagnostic capability of this new generation “Green” Zone Valve simplifies wiring, installation and diagnosis.

    It’s a Terrible System. Terribly Simple – Terribly Efficient!


  • THE CASE FOR SEPARATING HEATING INSTALLATION FROM SERVICE

    Our singular observation in over 50 years of hydronic (FHW) heating systems installation and service is this: Given any similar application, no two heating systems are configured the same, nor do they consequently service the same. Need they be? We argue that they definitely should be alike for both operational and service efficiencies.

    The impairment to maximizing hydronic efficiency and service lies within the heating market itself. Manufacturers supply components and installers apply them to the customer application employing their accrued experience. The obvious result is the installation variations we observe – “the good, the bad and the ugly” to apply the popular quotation.

    The problem is that even the good is not good enough efficiency-wise, and the installers get little help from their component suppliers, representatives and technical services in this regard. Specific to hydronic boilers, the “building block” of all FHW Systems, the manufacturer provides a generic installation guide with plumbing diagrams and wiring schematics that cover all the bases. No effort is given to efficient component sizing, placement or utilization. Much like an artist that is given a clean canvas with an image theme, the installer creates his own picture as he sees it.

    Ironically, there is an innate need for plumbing and heating guys to paint their own canvas. The daily tedium of fixing “leaks and squeaks” gets old very quickly. The opportunity to become creative by building a heating system on-site and making it look seemingly neat and pretty is a strong draw, not to mention a great payday as well. LEGO’s for Big Kids! Problem is, the customer pays for it up front, and continues to pay over the lifetime of the system in fuel, maintenance and operational costs, knowingly or not.

    From an engineer’s perspective the solution is quite simple, a designed and configured PRODUCT built specifically for the application. The quandary however is: How can you possibly accommodate so many applications and individual variations? There is seemingly an endless possibility of pipes, circulators, controls and valves to idealize an application. This has been the traditional dilemma — until recently. Technology to the rescue!

    Hydronic systems are undergoing a true design revolution with the development of “smart” circulators and zone valves. The combining of these reduces virtually any common residential or light commercial hydronic application to a single circulator and compliment of zone valves to suit. The resultant is a very efficient, flexible and yet simple system. We strongly recommend viewing our companion blog THE HYDRONIC REVOLUTION – THE INTELLIGENT DELTA-T CIRCULATOR FHW SYSTEM for further descriptive and technical details.

    Now to define a typical residential or light commercial system you only need to:

    1. Calculate the total heat loss of the structure.
    2. Specify a hydronic boiler and fuel type with suitable capacity.
    3. Select either a natural draft or forced exhaust venting.
    4. Qualify the use of an indirect water heater, if applicable.
    5. Determine the number of heating zones and their respective supply and return points.

    Note: These comments apply only to a Hydronic Boiler Packaged Product. Heating distribution compliments and completes the system, either as a new or in a replacement application.

    There are currently, to the best of our knowledge, no pre-built, assembled FHW Boiler Package Products applying the latest technologies, assembly methods, materials and logistics to support this emerging market. We are defining the attributes of this market to be providing:

    1. Hydronically optimized boiler package providing exceptional performance.
    2. Intelligent, ideal energy delivery and control.
    3. Complimentary supply zone distribution.
    4. Complimentary zone returns with service enhancements.
    5. Quick, simple on-site preparation and fitting.
    6. Ideally, availability on-demand.
    7. Expedient delivery to site, as required.

    Given the attributes and performance of this product, it will lend itself to service ease by any reasonably skilled personnel. The challenge remains to break the customer from the current norm of “one-stop shopping” for heating installation and service, the intent of this writing. It is only by providing and displaying the performance of such a product will we break the status quo — for the benefit of the consumer, and as an asset to the installer as well!

    We (Mercier Engineering) have participated concurrently in both high-technology manufacturing and the heating trades for over fifty years. An opportunity is now provided to us to participate in developing and marketing this Hydronic Boiler Product. Our career skill-set strongly compliments this task and thus we will be introducing a series of products to develop this emerging market.

    Please follow us on our website: www.BoilersOnDemand.com

    Our “Mission Statement” therein defines us and our goals..


  • FORCED HOT WATER (FHW) HEATING LOOPS – A BRIEF OVERVIEW

    Periodic discussions with Do-It-Yourselfers (DIY’s) prompts us to cover the subject of heating loops (radiation piping) frequently. These are particularly prompted by Steam-to-FHW Boiler Conversion inquiries that inevitably come to “how do I pipe my radiators if I want to use them?” A good time to review distribution piping.

    There are three (3) common variations of heating loops:

    1. The Series Loop – The most common configuration. Piping from one radiation element (baseboard, radiators, fan convectors, etc.) to another in a serial sequence and returning.
    2. The Split Loop (sometimes also called the Split Series Loop) – A larger pipe feeds to the middle of a series loop and supplies water to both halves, returning again by individual pipes or to a larger pipe, closing the loop to the boiler.
    3. The Monoflo(w) Loop – A larger, closed piping loop that continually flows water. Radiation is teed off this “runway” to both its ends, driven by a Monoflo Tee that pulls (moves) water through them by utilizing the “venturi effect”.

    The Series Loop is simple, but maybe too simple. How can you go wrong? Pipe from one radiation element to the next and close the loop from and to the boiler. Problem is, every fitting, foot and rise of pipe = resistance to flow. Resistance equals “head” that must be accommodated by properly sizing both piping and circulators to provide even heating. (You may want to also read our blog on “LAZY HEATING ZONES”.) The effects can be:

    1. Too small a circulator and/or piping size results in a “lazy” zone – temperature (heat) in the first heating element to the last can drop significantly, providing uneven heating.
    2. Install too large a circulator to overcome this and you risk “hydronic noise” created by over-speeding water. Take care to not create very long-piped zones as a practice.
    3. You inadvertently are loading your electric bill in either case. Longer circulation cycles in a “lazy” one or overpowering in the latter. Size and lay out zones properly.

    The Split Loop by nature is more efficient, requiring less power to move water and lessens the temperature (heat) differential across radiation significantly. It’s also a good way to get out of trouble with a poorly performing Series Loop – as long as it’s not too poorly configured. Strategically it’s also a good choice for future splitting into individual zones. Plan ahead.

    1. In new construction lay out your common feed(s) and return(s) so that you anticipate future lifestyle heating options.
    2. In old construction, re-pipe with feeds and returns to enhance current heating conditions while again anticipating future options.

    The Monoflo Loop is a technique that is currently seldom used due to cost. It takes a little more pipe (and time) to configure and requires a little more circulator to drive the venturi fittings, but if you want nearly simultaneous, even heating – this is it!

    Which brings us to the major current application for the Monoflo System, converting Steam Radiators to FHW Heating. Re-pipe every steam radiator into a two-pipe supply and return, and drive them with a Monoflo Distribution Loop. This is the only effective way to even out a radiator zone. There’s a lot of water in those radiators! Pipe them into a Series or even a Split Loop and you will appreciate the term “lazy” heating. DIY Steam to FHW System converters make note! The result is well-balanced, even heating with fewer, although more forceful circulator cycling.

    Know your heating loop options and do your technical homework related to pipe and circulator sizing for efficient distribution.

    Author’s Note: This discussion is predicated on contemporary fixed (single or multi-select) speed circulators. The hydronic distribution “ball game” has now totally changed with the introduction of Delta-T ECM Hydronic Circulation. It is applicable to both new and existing installations, providing dramatic electrical along with fuel consumption reductions. We are acknowledged application pioneers of this technology and have recently filed for Intelligent Property (Patent) Protection in the USA & Canada) on our ENHANCED CONVECTION, DIFFERENTIAL TEMPERATURE MANAGED, HYDRONIC HEATING APPLIANCE.

    Last Edit: 06/27/2017 pdm