• Tag Archives Heating Appliance
  • 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 inTaco®’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. TheHydrolevel® 3250-Plus Aquastat on our Weil-McLain® UO Boilerlogically 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


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

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

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

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

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

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

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

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

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

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

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


  • 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 while 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-fueled Appliance. Just change the burner —– 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


  • OUR UNPOWERED FORCED HOT WATER (FHW) GRAVITY HEATING SYSTEM

    Yes, we have an oil-wood (or coal) central heating system in our home that can fully function without ANY electrical power through outages and uses less power in normal operation as well. How? Gravity induced convection heating. It was initially installed in 1975 and been incrementally improved to date.

    We are unabashedly Weil-McLain Heating System Designers and Installers. This does not mean however that we kowtow to the heating fuel suppliers and pay-as-we-go! Living in rural, frosty New Hampshire our economic fuel options are limited to oil and wood only. (Propane is a substantial premium and Natural Gas is not available.) So it is not surprising that many of us use wood or a mix of fuels to survive economically. Therefore, wood, wood pellet, coal stoves and wood boilers.

    Particular evidence of this heating trend is the recent popularity of external wood boilers (Metal Storage Sheds with a smokestack sticking up out of them) that occupy many rural yards, next to a large woodpile. (Not to mention the well worn path from the house to the wood boiler!) As a facet of our enterprise we mention interfacing our Weil-McLain FHW Boilers and converting our Steam Boilers to accommodate them. Not surprisingly we get inquiries by sometimes frustrated users to assist in making the wood boiler work well with their central heating boiler. The stories can be a bit humorous, in fact.

    Let us first describe our subject system with the intent to provide you with the principles and applications we employed and from which you may benefit in your application(s).
    We have two (2) single-fuel boilers, centrally located in the basement level of a large split entry home that we built in 1970:

    1. A Weil-McLain Model 568 Oil-Fired Boiler, installed in 1995 and subsequently “tweaked” for performance.
    2. A 1935 Vintage National Heating Co. Economy No. 64 Wood Burner. Found, reconditioned and installed in 1975. A museum-piece that still runs very well.
    3. A 40 gallon “Hot Roc” Stone-lined Storage Tank coupled to the Old National that prevents a boil-off if it is overcharged with wood or used (carefully) for extra hot water (heating) storage.

    These boilers are commonly coupled to an overhead supply manifold and on-the-floor piping between return manifolds, physically separated by ten (10) feet. This layout provides for a simple, pure convection loop between them. NO CIRCULATOR IS REQUIRED!

    There are three (3) circulator driven heating zones off the Weil-McLain manifolds. These are FloChek Valved off the upper supply manifold with circulators on the return manifold.
    The two (2) upper (main) level Living and Bedroom Area Zones are of Split Loop Configuration (reference our recent subject blog for detail) and the lower level Office and Garage Loops are a Split Perimeter and Unit Heater configuration, respectively.

    Gravity Hot Water Central Heating has been around for over 150 years but was never too popular due to its restrictive design attributes. It is functionally a single zone, single level system where building characteristics allow. There is significant lag in response to a temperature change demand and if boiler control is not absolute, temperature control suffers as well. Nonetheless, where and when you can employ convective heating it can be beneficial from a distribution energy perspective (or a lack of it available).

    Our Split Loops are fed by 1” center tapped supplies and returns that feed conventional series 3/4” radiation loops on each halves. The loops are configured with conventional 1” FloChek, manually controllable seat, opening valves on the supply manifold taps. These FloChek Valves are always included in a hydronic (hot water) system to prevent natural continuous convective heating. If one fails you have continual heating in degree regardless of thermostat setting. Note: FloChek valves may also be incorporated within a supply side circulator.

    So we can use natural convective heating to our advantage. By employing a modest upward pitch to our Split Loop supply and return lines we augment gravity convection (hotter water rises, cooler water sinks) and opening the FloChek valves we have a “controllable” energy-free heating zone. The adjective “controllable” has to be qualified by trial and error settings over varying indoor and outdoor temperature demands.

    Let’s go through the four (4) Operational Modes available in our system:

    1. Powered, Oil-fired FHW “conventional” heating only.
    2. Powered, Oil and Wood-fired dual fuel heating.
    3. Powered Wood-fired heating only.
    4. Powerless Wood-fired heating.

    Powered, Oil-fired FHW “conventional” heating mode is conventional in all regards. There is an “open on rise” aquastat (adjustable) on the wood boiler that performs two (2) functions:

    1. Inhibits the oil burner boiler primary control when the wood boiler temperature setting is reached.
    2. Opens a motorized valve to enable the inter-boiler convection loop to operate.
      “Set it and forget it” applies.

    Powered, Oil and Wood-fired dual fuel heating is enabled when the wood boiler aquastat engages and disengages the oil burner and the convection loop valve as wood burning proceeds. There is a second aquastat on the wood boiler supply pipe that “closes on rise” as water temperature approaches the boiling point (set at 200F). It opens a zone valve that initiates a second close-coupled convective loop allowing room temperature (or above) water in the “Hot Roc” Tank to temper the boiler water temperature. So if you overfill the wood boiler and walk away there is no consequence. Works beautifully! This feature is referred to as a “Dumping Zone” – getting rid of the excess energy.

    Powered Wood-fired heating only operation is similar to the oil and wood mode excepting the oil burner is fully disabled by moving the wood boiler aquastat to its lowest setting nearing ambient room (and therefore water) temperature. We have another option on our particular oil burner primary control of a built-in switch-off feature. (A common switch could also be employed to open this wood boiler aquastat to primary control circuit.)

    Powerless Wood-fired heating is merely emulating the operation of the powered mode while adjusting FloChek Valves on your heating zones and maintaining your wood boiler temperature range. In fact you can strike a boiler charging pattern that can free you from full-time babysitting the “dragon”. Our Samson 5D (Expansion Slug Type) Boiler Controller will maintain a temperature setting reasonably well on the Old National excepting when you seriously overcharge the beast — then things start happening! When the pipes start banging you have to “expeditiously” open the “Dump Zone” Tank Valve manually to temper it down. You learn this lesson in a hurry!

    To summarize, we used the wood only mode (powered and powerless) continuously for nine (9) consecutive years, providing full-home corner to corner heating and providing our domestic hot water for our large family. (The summer season requires a little lifestyle scheduling.) Annual wood consumption was four (4) to four and a half (4-1/2) cords per year.

    Since that time our lifestyle changes have precluded wood-only operation, but it’s there if we need it. Evidencing a severe ice storm a couple years ago that crippled most of New England for over a week, it was a mere inconvenience to us.

    Unfortunately gravity convection heating has little applicability to the current external wood boiler rage. They require electrical power for operation. The internal wood boiler is another matter, such as is employed in our case. Hopefully some of our experience can be used in configuring your system or trimming a little operating cost from it.

    Author’s Update: 11/28/2020

    We have incorporated our gravity heating experience into what we believe to be the first, practical, efficient and affordable Pre-built “Delta-T ECM Hydronic (FHW) Heating APPLIANCE”. An extensive U.S. Patent 10,690,356 was issued to us on 06/23/2020 with all our Fourteen (14) Claims allowed. A Canadian Patent is to follow. Check it out at www.BoilersOnDemand.com.