• Tag Archives Distribution
  • 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 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


  • THE “DELTA-T” FHW HEATING ADVANTAGE

    Whether you’re replacing an existing boiler or installing a new Forced Hot Water (FHW) Heating System, the procedure is the same. A plumbing/heating guy moves in with a service truck full of parts and tools, a supply house truck arrives and drops the boiler and sundry parts. Then the game begins …..

    The old boiler (where applicable) is removed by whatever means required, the ensuing mess is cleaned up, and the new boiler is moved into the area. Locating and positioning the boiler is the first task and directly determines the effectiveness of the entire installation. The preferences, methods, materials and the heuristic judgement of the installer prevails. Thenceforth the building of the “Erector Set” continues, pipe by pipe, wire by wire, device by device until the task is finally completed. It’s a slow, costly and inefficient process …..

    All tradesmen develop their own methodologies, reflecting their pride and workmanship in the resultant. Unfortunately the customer pays a premium for this both initially and throughout the lifetime of his system ….. knowingly or not! We cynically refer to boiler installations as “The Plumber’s Playground”, that last vestige of “free expression” removing us from the daily tedium of “fixing leaks and squeaks”.

    Installing or replacing a boiler should be no different than a dishwasher or a water softener, with a few more pipes and wires attached ….. and it can be! Problem is we plumbing/heating guys (ourselves included) continually lag technology. We “Old Dogs have to learn New Tricks”, and brother we have!

    Recent technology now allows us to configure a FHW (Hydronic) Heating System as a true appliance! All heating system functions excepting radiation can now be integrated into a “packaged unit”, engineering it for peak performance and value in the process. “Delta-T” (Differential Temperature) Circulation Technology is truly an evolutionary and revolutionary improvement. Developed in the “high-tech” process world, it has now become both practical and economical as applied to Residential Hydronics (FHW Heating).

    Mercier Engineering via its website www.BoilersOnDemand.com is the introductory leader of Residential Delta-T Hydronic Heating. The question is not if Delta-T Circulation will out-distance conventional Fixed-Speed Circulation, but when. Evidence the following Pictorials and Details for comparison.

    Identically Configured Oil-Fired FHW Installations          

    Conventional Oil-Fired FHW System   “Delta-T” Oil-Fired FHW System
    Typical Plumber Boiler Install - 18 hrs DTO-100T2(Exp)H4-4X6

    Features Comparison Table

    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

    Notes:

    1. Estimated service lives are from our and our collaborating serviceman’s actual field experience.
    2. Fuel & Electrical Energy Performance per Taco, Inc. published testing data.

    Reviewing our Comparative System Photos will will confirm many of the suppositions in our “Features Comparison Table” above. The immediate impression is one of excessive plumbing and space consumption of the Conventional System. In fact the “Delta-T” System occupies 1/3 of the space, uses 1/2 of the near-boiler piping (with no copper), with only one (1) Circulator, fewer valves and fittings ….. and with optimized hydronic flow and distribution performance! Flow is so idealized in fact that under certain component fail modes “gravity induced circulation” will continue to provide heating at a reduced level! (Patent Pending)

    Arguably a high-mass (heavy) “Delta-T” System will outlast two (2) Conventional FHW Systems with a higher Hydronic Total System Efficiency at 1/3 the “life-cycle” cost.

    So when your potential FHW Heating System Installer comes calling, ask him first about “Delta-T” Circulation. If it draws a blank stare, send him home to call Taco, Inc. — and that another “Old Dog” told you to do so. After all, you the customers are deserving of all the “New Tricks”!


  • 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!


  • INTERIOR VS. OUTDOOR WOOD BOILER SYSTEMS — SOME OBSERVATIONS

    Having now maintained our own Interior, Integrated Wood & Oil Heating System since 1975 and more recently coupling Outdoor Wood Boilers to our Weil-McLain FHW Heating Systems,  we are motivated to pass on some of our observations.

    (Note hyperlinks within the document.)

    Disclaimer: We are exclusive Weil-McLain Heating Designers & Installers here in NH only (thus far). We do not nor have not specified, sold or initially installed any interior or outdoor “Solid Fuel” (Wood, Pellets, Coal, etc.) Boilers. Our participation has been to occasionally help out a customer integrate these products with our Weil-McLain Hydronic Heating Systems per our personal experience. Included has been converting Steam Boiler Systems to FHW and conjoining these systems.

    Note: We offer as an option full-size fittings (plugged) at our boiler supply and return points to integrate other boilers. Specify at ordering.

    The recent popularity of Outdoor Wood Boilers in particular has prompted many inquiries and discussions on our part. They seem however to neglect the interior-located solid fuel boiler in the scope of options. Each of these have distinctive attributes that both complement and complicate their integration and operational effectiveness.

    Inside or outside? That is the (first) question and may likely be answered by The Regulators (Zoning, Fire and Insurers). Specifically to wood/coal boilers:

    1. The Local Zoning Code will define permitted use and location parameters. (Outdoor Boilers are particularly vulnerable to NIMBY (Not In My Back Yard) and more specifically regulated.)
    2. The Fire Codes usually reference both, but are tough on Interior Boilers.
    3. Insurers (risk takers) then determine how much it is going to cost you to save money. Again, interior boilers take the major hit, especially if it is the primary energy source.

    Note: The delineation is between Gas/Oil-fired Power Burner Heating Systems and Solid-Fuel Fire (Coal/Wood, etc.) Systems. Insurers will usually bend for Automatic Stoker-fed Coal and Automatic Wood Pellet Systems with a two-week continuous-feed fuel storage supply. Check your local codes and insurers, however.

    At the risk of oversimplification and generalization we offer the following:

    TypeFlueLoop LengthLoop LossesStandby LossesEfficiency (Overall)
    InteriorReq'dShortLowLowModerate to High
    OutdoorN/ALongHighHighLow to Moderate

    Explanations:

    Flue:
    Any Interior Wood/Coal Heater REQUIRES A DEDICATED CHIMNEY FLUE! Flue quality must also be considered to support a continuous fuel fire. A “sometimes option” is to convert the primary powered burner (gas/oil) appliance to a “direct vent” device vs. the additional flue construction cost. Check it out.
    The Outdoor Wood/Coal Boiler has its own integral exhaust stack. However it is not unusual to see vertical stack added, sometimes up to 20 ft. to improve draft or smoke dissipation conditions.

    Loop Length:
    An Interior Wood/Coal Boiler can be readily be coupled to a FHW System, given flue location options. Interior Boilers are typically like-pressurized and therefore operationally compatible.

    An Outdoor Wood/Coal Boiler is typically “Zero Pressure” to simplify construction, ease of operation and complexity. This comes at a price with a continuously-powered, “high head” (flow resistance) system loop to the FHW System using a tough circulator. An in-line Heat Exchanger is required to mate the pair. Significant heat losses occur as well.

    Loop Losses:
    Interior Wood/Coal Boiler Loop Losses are typically dissipated to the ambient surrounding area and usually indirectly contribute to the heating of the structure.
    Outdoor Wood/Coal Boiler Interior Loop Losses are as prior, but Exterior Losses are very significant! (We have a system with over 400 feet of high quality, insulated two-pipe, buried down several feet. You can readily observe the reduced/absence-of-snow line path.) You must further isolate the “Zero-Pressure” Outdoor water from the interior “Pressurized” water using a “Plate-To-Plate” Heat Exchanger System with controls & circulators. This system contributes some heat to the ambient area, however.

    Standby Losses: (Defined as energy losses between heat demand cycles.)
    All Interior Boilers dissipate energy between cycles to the ambient and incur flue losses (heat up the chimney). The chassis and piping energy is generally accepted to be contributing to the heating environment positively excepting during the non-heating season.

    All Outdoor Boilers lose significant energy both from their chassis (never any snow on them) and their exterior service loop if circulation is not inhibited with demand. All this is lost energy by definition.

    Efficiency (Overall):
    Albeit being an empirical determination, the relative efficiencies of interior vs. outdoor boiler systems will be effectively higher due to their placements (in heat value areas) and reduced loop and standby losses. Thus the terminologies assigned and relationship to each other.

    Note: We are not addressing the Heat Generation Efficiencies of any boiler products in our discussion, these varying by configuration(s), but only their overall performance by type. Open the NH Climate Audit Calculator  (Excel Doc). It’s a useful tool to both qualify and quantify your options by “playing the numbers”. Our “trick” is to calculate the “Cost per Million BTU” for a selected fuel, then adjust other fuel costs to equal your selection MBTU value. Remember to adjust your fuel appliance efficiencies if known or use the defaults. The resultant is a great “apples to apples” economic comparator!

    Operational Observations:
    Further observations of field operation leads us to believe that many outdoor boiler users fire them virtually continuously, incurring very poor fuel utilization, during low heat demand periods. Perhaps there is a continuing need for DHW (Domestic Hot Water) Generation without a storage means provided, or an unwillingness to build a new fire.

    We have evidenced outdoor wood systems consuming 11 cords of wood that in our humble opinion should be consuming no more than 5 cords with an interior boiler, 45% of the outdoor unit. Granted this is a very heuristic and unqualified determination, but yet an indicative one.

    Whatever the case, if one presumes to maximize his fuel utilization the household must adapt to the characteristics of the solid fuel fired system. “Showers-On-Demand” will likely require a generously sized Indirect Water Heater (Super-insulated DHW Storage Tank) to accommodate this lifestyle. Otherwise an incremental or even seasonal fallback to the gas/oil-fired system may be necessitated, and desirable.

    There is a tendency of auxiliary wood/coal users to “over-engineer” their systems. A prolific use of circulators, relays and controls result. We would respectfully suggest that exploring the use of Taco® Delta-T ECM Circulator Technology  would benefit energy management. Further, employing Taco® Zone Sentry Valves with these permit some emergency (no power) gravity heating on interior boiler systems.

    Conclusions:

    1. Outdoor Wood Boilers appeal to users who have larger fuel demands, an abundant, low-cost supply of particularly cord wood, time and resources available to process it! (As we say: “Wood warms you twice!”) Higher equipment installation costs and poorer total fuel efficiency is a definite factor in their consideration.
    2. Outdoor Wood Boilers in particular require continuous electrical energy for combustion and distribution. No Power — No Heat! (Or it’s own a generator, too.)
    3. Interior Coal/Wood Boilers are operationally more desirable, but regulatory influences must be qualified and satisfied.
    4. Installed Costs of any dual-fuel system are substantial. To minimize this and achieve predictable performance, use of a qualified technical resource is recommended. Utilize a “system guy” and not just a “tech-sketch” provided by the boiler salesman.
    5. Not maintaining ideal and consistent heated water delivery in any system takes its toll on equipment, in particular circulators, through very long duty cycling.

    Our Personal System and Performance Data:

    Referencing our Blog on our personal system, we offer the following:

    1. Operating as an oil-only system between 1971-1975
      • Annual Fuel Oil Consumption: 475 Gallons x 140KBTU = 66.5MBTU/Yr @ 85% Efficiency = 56.5MBTU/Yr. Net Usable Energy
    2. Operated as a wood-only system between 1986-1995 (9 yrs.)
      • Annual Wood Fuel Consumption:  4-1/2 Cords average x 20MBTU/Cord = 90MBTU/Yr. @ 60% Efficiency = 54MBTU/Yr. Net Usable Energy
    3. Operating as a dual fuel system otherwise between 1975-1985 and 1995 to date. We have been using only a modest amount of wood in recent years, restricted by wood fuel costs and time constraints.

    2016/2017 Full Heating Season: 460 Gallons of Fuel and 1+ Cord of Wood + combustible paper & other waste, as available.  (Admittedly approximations.)
    10 Room Single Family Home, Built 1970, Heated Area: 2,016 Sq Ft
    3-1/2 Zone, Programmed T-Stats, Coupled FHW Oil and Wood Boilers. DHW Immersion Coil on Oil Boiler. Planned Upgrade: Large Indirect Water Heater (HTP SSU-80) for DHW to permit less low/no heating season boiler cycling. TBD.
    Annual Degree Days: 7,500 Average (SW NH)

    Comments:

    Dual-fuel and in particular interconnected FHW boiler systems offer a good heating option, given they be properly configured and operated. We have a long ways to go however to inform and guide customers in their economics, application and execution. It is our hope that this document is of some help toward this end.

    Author’s Note: Updated 10/13/2017


  • 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


  • “PLUMBING GUYS PLUMB, HEATING GUYS HEAT” — AN OBSERVATION

    You have doubtless noted the “Plumbing & Heating” Logos on Trade Vehicles. Both disciplines are related, specifically to FHW (Forced Hot Water – Hydronic) Heating Systems, but not necessarily synonymous. They share similar tools and some materials, but not the same techniques — and it shows!

    At the risk of categorization and classification we can readily identify with surety who installed your heating system, i.e. a plumber, your brother-in-law, a DIY (Do-It-Yourselfer) or a heating specialist. The levels of knowledge, application skills and techniques define the end product, and its net performance and efficiency. To quote the axiom “the devil is in the detail” certainly applies to this observation and how the details affect system operation, efficiency and maintenance.

    Ideally you want a FHW System that is finely tuned for performance, notably:

    1. The highest economically efficient energy producer (boiler)
    2. Hydronic components selected for operational efficiency and life cycle cost
    3. Circulation and radiation options complimenting your structure and lifestyle
    4. Complimentary, efficient DHW (Domestic Hot Water) Generation
    5. Optimized hydronic distribution (piping) and zoning

    Prefacing our remarks, do not do a thing until you know your aggregate needs for heating energy! There is no excuse or recovery for not knowing this up front. A Heat Loss Calculator (see other blogs) is not outside the capability of a homeowner or DIY’er, not to mention the professional. Also the Calculator is a great tool for playing energy improvement scenarios prior to making money decisions. Git-er-done!

    Boiler sizing is usually our first observed misapplication, virtually always too large for the current application. In fairness to the original installer and dating of an aging boiler, the existing structure and boiler inefficiencies were a factor as well, along with over-sizing practices at the time. Unfortunately the resultant of subsequent energy improvements and old indiscretions combine to make the boiler now substantially over-sized and an even greater stand-by loss energy robber. (See other blogs)

    Additionally there are the “plumber’s boilers”, as called in the trade. Same so-so boiler, same techniques for decades. Even this “old dog” has had to learn some “new tricks”. The new Triple-Pass (Oil) and Condensing (Gas) Boilers offer us very efficient new tools — with new rules!

    Near-Boiler Plumbing (includes the boiler and Distribution (Zone) piping) is the next focus area. Indicative poor practices are:

    1. Bushings in boiler supply and return outlets, reducing outlet piping sizes at the peril of high stress and corrosion prone fitting failures at the boiler. (We use Heavy Series Nipples and Reducing Elbows, Tees or Couplings to avoid this structural risk.) Such failures are so much fun!
    2. Continuously hard-piped (supply and return) manifolds, with too many fittings and no repair or boiler removal provisions. (More fun!)
    3. Extended length manifolds with high cantilevered loads (weights), sometimes anchored to the floor, wall(s) or overhead construction for support. (Here’s our “Compact Steel Hydronic Header” – Patents Pending that addresses this problem)
    4. Poor (or no) manifold flow proportioning.
    5. Lowered return manifold and piping.
    6. Lots of copper piping vs. iron.
    7. Misplaced, excessive or insufficient valving.
    8. Circulation and/or Zone Valve application and placement.

    The added Indirect Water Heater installation is virtually always “hacked”, i.e. however neatly installed it is thermally compromised. Too much, inappropriately sized, and somewhat under-insulated piping usually stretched from existing boiler manifolds contribute to unnecessary seasonal stand-by losses. (Our “Secret”: We “close-couple” Indirect Water Heaters directly to the first-off-the-boiler fittings to minimize heat loss. The system manifolds are unheated seasonally, save a little convective heating under the insulated riser piping.)

    The guy who has to service a boiler knows best where to place service components (water pressure regulator, circulators, valving, relays, service switch or clean-out accesses)! We position all of ours within an arm’s reach for servicing efficiency.

    A point to ponder: Every extra foot of piping, every elbow, foot of water head-height and gallon of water, through every fitting and valve consumes more energy to accomplish the heating task. Distribution efficiency is totally disregarded by every contemporary hydronic (FHW) heating system installer!

    Example: A past “boiler swap” in an apartment house yielded an excess of 35 feet of copper pipe lengths, many shorter “cuts”, fittings, etc. The new Triple-Pass Weil-McLain Ultra Oil Boiler fires @ 70% of the prior 30 year older Weil with new, appropriate wet-rotor circulators uses 40% less fuel and supplies endless DHW through an 80 Gal. Indirect Water Heater. Every little bit counts — and counts up!

    If it’s any consolation, many of the “old dog” plumbing guys are closing out their careers. Now we other “old dog” heating guys that are determined to continue adapting and applying our skills and experience using the new heating tools have our days in the sunlight. Problem is, we have a lot of consumer educating to do. Hope that jabbing our plumbing brothers a bit makes this ever more apparent.

    To emphasize this point look at our Enhanced Convection Delta-T ECM Hydronic (FHW) Heating Appliance – Patents Pending (USA & Canada) and our supporting website www.BoilersOnDemand.com.

    If our fellow “Plumbing & Heating” Tradesmen need assistance in efficiently applying the latest in hydronic distribution technology, perhaps we can help them ….. or you, the consumer directly with America’s First Hydronic (FHW) Heating APPLIANCE™!

    Updated 08/01/2018 P.D.M., Sr.