• Tag Archives Delta-T Circulation
  • Our Feature Article “BEYOND AFUE TOWARD HYDRONIC HEATING SYSTEM EFFICIENCY” Published In Plumbing Engineer, May 2016

    We are both humbled and pleased to confirm that our Feature Article “BEYOND AFUE TOWARD HYDRONIC HEATING SYSTEM EFFICIENCY” has been published in the eminent Trade Journal “Plumbing Engineer” in its May 2016 Issue.

    It documents our efforts to apply Delta-T ECM Circulators as Dedicated System Circulators in Hydronic Systems. Mercier Engineering is the INDUSTRY FIRST to do so, culminating a three (3) year development and field testing effort.

    We aspire that the Hydronics Industry and ultimately the Heating Consumer may benefit from our work.


  • 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”!


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

    Periodic discussions with Do-It-Yourselfers (DIY’s) prompt the subject of heating loops (radiation piping). In particular Steam-to-FHW Boiler Conversion inquiries inevitably ask “how do I pipe my old radiators if I want to keep them?” A good time to review distribution piping.

    We must preface by stating that traditional perimeter “fin tube” radiation loops are the simplest and most efficient means of heating a structure. They lessen piping lengths, head pressure (flow resistance), minimize material & labor costs and require less circulation (distribution) energy. Beware the contemporary plumber or heating installer who claims that all of his additional “pretty piping” and controls increase performance. To the contrary! Powered air handlers, cabinets and radiant heating loops all require additional hydronic and electrical energy.

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

    1. The Series Loop – The most common configuration. Supply 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 (or pair) feed to the mid-point of a series loop, supplying water to both halves and returning by individual pipes or a larger pipe, closing the loop to the boiler. A hydronically balanced circuit is necessary to minimize distribution energy.
    3. The Monoflo(w) Loop – A larger, closed piping loop that continually flows water. All radiation is teed off this “runway” loop to both of its ends, driven by a Monoflo Tee that pulls (moves) water through them by utilizing a “venturi effect” pipe tee.

    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 onLAZY 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(w) 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 through the required venturi tee fittings. But if you want nearly simultaneous delivery and even heating – this is it! Most often found on older baseboard or converted cast-iron radiator systems.

    There is additionally a seldom used TwoPipe, Reverse Return Method as a proven way to evenly supply larger radiators or other convectors. A dedicated supply pipe (manifold) is routed and branched to each convector. A similar, separate return pipe (manifold)  is likewise routed and branched to each and back to the boiler. Key is to return flow in the opposite direction to that of the supply, i.e. the first radiator supplied is the last to return. FIFO = “First In, Last Out”. This reasonably balances delivery and lowers head pressure in a properly proportioned, dedicated supply and return “pipe manifold” system.

    We finalize with the major current application for the Monoflo or Two-Pipe, Reverse Return System, converting Steam Radiators to FHW Heating. You MUST re-pipe every steam radiator into a separately piped supply and return, then drive them either with a Monoflo Distribution Loop or a Two-Pipe, Reverse Return System. These are the only effective ways to even out any large radiator-based zone. There’s a lot of water in those radiators! Pipe them into a Series or even a Split Loop and you will soon appreciate the term “lazy” heating. So, DIY Steam to FHW System Converters in particular take note! The result is well-balanced, even heating with less, 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 some 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. All in the quest for Simple, Durable and Efficient Hydronic (FHW) Heating.

    Last Edit: 05/28/2020 PDM, Sr.