• Tag Archives 3250-Plus
  • 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


  • SIMPLE, DURABLE, EFFICIENT FHW HEATING ….. PERIOD!

    Our Motto is “Simple, Durable, Efficient FHW Heating ….. Period!”. Boilers On Demand LLC has achieved this seemingly noble objective by fully integrating Advanced Taco Delta-T ECM Hydronic Distribution Technology into Forced Hot Water (FHW) Heating . The unstated result of our “Convection Enhanced Delta-T ECM Hydronic Heating Appliance” (Patents Pending – USA & Canada) development is it being highly cost-effective as well. Can we “have it all”, so to speak? Let’s look at our effort in further detail …..

    Hydronic (FHW) Heating to the layman and consumer has always had a certain mystique, evidenced by witnessing a tradesman or plumber configuring a system, piece-by-piece into a seeming maze of piping and components. The results vary from the mundane to aesthetically impressive, but we must realistically note in fact that the hydronic performance of any system is less than ideal. The residential and light commercial heating markets in particular have not had the tools nor the general expertise to optimize a hydronic heating installation. Consequently the end user has suffered with an over-installed, under-performing, energy-consumptive system over its lifetime ….. knowingly or not!

    Note: We can’t excuse our like personal participation for now sixty (60) years in hydronic heating. Our guilt is shared ….. but no longer!

    Now a true “hydronic revolution” is upon us, not yet generally known and even less appreciated, nor applied. Hydronics have thankfully been somewhat forgiving to all of us applying it, but now there’s a new day, and a new benchmark.

    By explanation, there are three (3) basic elements to hydronic heating: Energy Creation, Distribution and Radiation. Put more simply:

    1. A Hydronic Boiler to create energy by burning a fuel, as efficiently as possible.
    2. Moving (distributing) heated water to points of use with “pipes and pumps” (circulators).
    3. Warming an environment by passing air over hot piping, as simply and effectively as possible.

    We have progressed quite well in creating and utilizing energy via boilers and radiation, but that is where it has stagnated far too long. Given the limitations of fixed or selectable speed circulators and valving we have managed without addressing the true potential of improving hydronic distribution efficiency to complete the heating equation. The intelligent, variable speed Delta-T (ΔT) ECM VT2218 00e Series Circulator by Taco Comfort Solutions® has changed it all ….. and none too soon!

    We have been experimenting with Taco® Variable Speed Delta-T VDT’s, “BumbleBees”, Viridians and now 00eSiries ECM Circulators for years, utilizing them as direct substitutes for their fixed-speed predecessors. They have worked particularly well as radiant zone circulators as our fellow tradesmen have also discovered. The Taco BumbleBee® in particular has gained trade notoriety both by its appearance and performance. However, our personal technical efforts have gone well beyond the obvious in pursuing a dedicated boiler system circulator application. It has neither been promoted nor seeming anticipated, yet its implications are very significant when achieved.

    Utilizing a Delta-T, and in particular an ECM (Electronically Commutated Motor) based circulator as a single, dedicated system hydronic “distributor” offers near-ideal efficiency potential. We slogan it as “putting an ‘Automatic Transmission’ on a boiler”. It greatly simplifies both near-boiler piping and control complexity, but must necessarily possess several operational attributes:

    1. First and foremost is reliability! A dedicated (single) system circulator failure is a potential “show-stopper” after all.
    2. Performance Flexibility. It must adapt to and accommodate all system energy demand patterns with minimal, if any effect.
    3. Accommodate an Indirect Water Heater as a prioritized and an incrementally higher energy demand accessory.
    4. Significantly improve system efficiency and performance while reducing energy requirements, both fuel and electric.

    Zone Valves are a necessary compliment to manage individual zone demands when using a single circulator. New generation valving and in particular the Taco Zone Sentry® Valve provide outstanding performance and value with self-diagnostics. The “Zone Sentry” in fact delivers three times the heating capacity of its popular “Heat Motor” predecessor, and uses dramatically less power. Combine these with its physical packaging attributes the “Zone Sentry” provides a unique configuration opportunity further addressed in this writing.

    The hydronic distribution function is composed of two elements:

    1. “Near-boiler piping” as generally referred includes circulators, valves, air elimination and expansion devices that prepare and present heated water or “hydronic energy” to points-of-use.
    2. Distribution piping that extends and presents this heated water energy to radiation components.

    We offer that considering these two distribution tasks without differentiation or distinction is fundamentally flawed, and yet is standard trade practice. As initially stated, Delta-T Distribution Technology changes this assumption, and dramatically! Consolidating hydronic flow within a single, intelligent system level circulator packaged with complimentary, intelligent zone valves packages into a true, efficient FHW Heating Appliance. Further, “hydronic convection” (gravity heating), the natural attribute of heated water to rise and convect within distribution piping is idealized as well. Witness the need to install “flow-check” valves in conventional systems piping, into circulators or using properly sited zone valves to control convection (gravity) heating. By incorporating natural convection total circulation energy is measurably reduced beyond that of Delta-T. A simple analogy would be “like paddling your canoe with the current, rather than against it”.

    Hydronic convection performance is at the core of our Proprietary Near Boiler Piping System. Included as a standard, recommended option for idealized system and DHW (domestic hot water) creation efficiency is an Indirect Water Heater (the HTP SuperStor Ultra Series). Close-coupled within our near-boiler piping, its integrated supply architecture becomes a physical, gravity flowing extension of boiler capacity, particularly in circulator fail-mode operation. Yes, we had a “fluke” 1st Generation Taco Viridian® VT2218 failure on our “Beta #3” site that was not discovered for an estimated 2-3 days of heating operation. DHW generation was never affected!

    Ideally complimenting our hydronic system is the highest-mass boiler for its rated output (the Weil-McLain UO Series), extending system energy storage capacity and potential fail-mode convection performance. Its supply and return rear porting compliment near-boiler piping by compactly and efficiently packaging all hydronics within its footprint plus an approximate 1 ft. rear piping and exhausting space. Adding the Indirect Water Heater uses under 12 sq. ft. of combined space, up to 2/3 less than a typical currently installed system while reducing system valving and near-boiler piping by up to 1/2. Integrating with domestic all-steel piping, malleable fittings and brass/bronze valving compose a free-standing system architecture of innately superb strength, chemical resistance and field proven longevity.

    Now applying our paralleled “High-Tech” Manufacturing Process expertise to Hydronic Heating, we have modularized, value engineered, methodized and tooled our Delta-T ECM Hydronic Heating Appliance to include several additional components in our Intellectual Property Protection (Patent Pending) Submission. Our cooperating customers on multiple “Beta Sites” are also providing us valuable data to optimize our system design and performance with the goal of providing an unbeatable cost-performance product.

    Taco Comfort Solutions® publishes that its Delta-T ECM VT2218 00e Series Circulator provides up to 15% fuel and 85% electrical power reductions in applications. We certainly concur! Our dedicated VT2218 system circulators are using 8-13 Watts in heating maintenance mode. Cold system warmups begin at 25-35 Watts (half the rated power) then reducing toward acclimation temperatures.

    At the extreme of our experience is our “Beta #1″ Site upgrade, badly mis-piped with three hidden, seriously undersized 1/2” radiation zone supplies & returns that exhibit high head pressures (obviously). A pre-existing integral IWH is also under-sized piped, adding to delivery issues. Yet, this system cold starts @ 65 Watts, decreases rapidly to 35 Watts, then slowly acclimates to 22-25 Watts running. (A single Taco® 007 draws up to 80 Watts by comparison. It had four operating three heating and the IWH zones.)

    Additionally by using the High-Mass Weil-McLain UO Series (Oil) Boiler(s) we see system operating temperatures lowering to 132-140º F, regulated by its integral Hydrolevel “Fuel Smart” HydroStat® 3250-Plus Aquastat. System demands are readily “cushioned” by the thermal mass provided in the total system architecture. It responded very positively to the prior noted prototype system circulator failure, ramping up system temperature toward maximum with zone duty cycle duration detection & response, maintaining radiation heating in degree. Boiler burner cycles are infrequent and brief, further reducing equipment maintenance levels while extending system operating life.

    We have more recently offered the appliance-specific Carlin EZ-PRO Gas (NG&LP) vs. the Beckett NX Oil Burner in the Weil-McLain UO Boiler. Now it’s a Universal Hydronic (FHW) Heating Appliance! Change fuels ….. swap the burner only!

    Total Hydronic  (FHW) Heating System Efficiency is  the AGGREGATE  of Boiler AFUE, Delta-T ECM Hydronic Distribution & Radiation Efficiency Gains! We further claim that the reduced operating system temperatures and hence stand-by losses of the very high mass Weil-McLain UO Boiler further increase overall efficiency. Thus we can confidently claim the highest efficiency heating system available!

    System Comparison

    “Conventional” FHW Heating System         vs.         The Delta-T ECM Hydronic System

     

    Identically Specified 100KBTUH, 2-Heating Zone + IWH, Oil-Fired Systems

     

    Attribute"Conventional" System"Delta-T" SystemComments
    Boiler TypeWelded Steel Plate (Example Unit)Cast Iron "Triple-Pass"15 years +/- vs. 30 Years +
    Boiler Weight270 Lbs.625 Lbs.Very High Mass - Durability
    Oil Burner TypeVarious OfferedBeckett NX (Pressure-Fired)Flexible, stable operation
    Gas Burner TypeFixed, Appliance-SpecificCarlin EZ-PRO (NG/LP) (Pressure-Fired)Appliance-Specific Interchange
    CirculationMultiple Fixed Speed Circulators onlyA Delta-T Variable Circulator w/ Intelligent Zone Valves>/ 15% Fuel Savings
    >/ 85% Electrical Savings
    Piping/FittingsCopper (Typically)All Iron & Cast ConstructionSuperior Strength/Durability
    Indirect Water HeaterVarious Mfrs. & TypesAll Stainless Steel OnlyA Lifetime of Service
    Floor Space UtilizationInstaller-dependentOptimized Package DesignMinimum Space Requirement
    Energy PerformanceInstaller-dependentOptimized Energy DesignPeaked Hydronic Efficiency
    Component SourcesU.S./Foreign Mix (Typical)"All-American" (US/Canada)Quality and Serviceability
    Installed Cost (Oil example shown)"Over $10,000" (Oil, as shown)$7,000 (Oil, as shown)Price, Performance, Value

    To Summarize:

    Taco® Delta-T ECM Hydronic Distribution changes everything! The “Plumber’s Playground” of conventional, inefficient hydronic distribution piping “free expression” is gone as well! We must now look at Hydronic (FHW) Heating in totality, no longer as a an aggregation and assemblage of parts by personal preference. Technology has provided we heating guys with some new working tools. Let’s learn how to use and apply them well!

     Author’s Note: Updated 10/01/2018


  • 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