• RELINING A CHIMNEY – Do Your Homework First!

    Posted on by Paul Mercier

    Our post is motivated by recent instances of poor chimney relining and their effects on heating system operation. It seems that some installers are gaming or ill-advising consumers with poor installation practices. Again you, the customer should set the requirements, not the provider!

    There is no substitute for consumer education, and let us preface by merely stating: Your chimney must match or exceed the boiler or furnace manufacturer’s specification. Their requirement will always be found in your appliance manufacturer’s Installation Manual. With few exceptions (obsolescence?) these are available on manufacturer websites. Occasionally a tradesman’s account may be necessary or require a direct contact.

    The first question to resolve is that your chimney actually needs relining. This is a question to be resolved with a competent Home Inspector. There may be a further economic value adder to your real estate to consider. Do not assume that updating a heating appliance should necessitate a relining. A newer generation boiler for example will typically exhaust a lower temperature and volume of combustion products.

    Presuming a relining is in order, the diameter (or it’s effective sectional area – length x width) requirement of your appliance must be determined and specified. Your existing flue may in fact be larger than necessary, but again specify your required diameter or cross-sectional area.

    There are two (2) common materials used as chimney liners, stone refractory tile and stainless steel. The former is typically used in new masonry construction, but can be retrofitted into and old chimney where downsizing to accommodate it with filler is available. Corrugated, flexible, round stainless steel liner is currently the most popular and to abuse the terminology a “quick & dirty” fix, albeit somewhat pricey. It is also vulnerable to cost-cutting and shoddy practices.

    Let’s explore recent examples to qualify our observations and statements:

    Case 1: A Public Weatherization Program Installation

    Seven (7) years ago this home was retrofitted with a Weil-McLain WTGO-3 Boiler with a 7″ Exhaust Flue and 8″ Dia. Chimney Requirement. At the same time the chimney was relined with a 6″ Dia. Stainless Steel Liner. The Boiler Flue Piping was then “frenched”, i.e. slit, tapered and forced into the 6″ Liner extension and sheet metal screwed to secure. It must be added that the original chimney was unlined, 12″ square brick construction. The chimney clean-out was removed and the base filled with scrabble and mortared to just below the flue outlet. The larger initial flue cavity permitted the bending of the 6″ Liner to act as the flue outlet as well.  A chimney-top weather cap was installed (reducing draft) to eliminate rain & snow from running down the chimney and then into the Galvanized (rusting) 7″ Exhaust Flue Pipe.

    Upon firing, despite a burner 15 second “pre-purge” cycle, the flue Barometric Damper inverts with a bang, expelling an amount of flue product into the basement area, but quickly recovers to positive draft as the chimney liner warms.  Firing the boiler with the service port open similarly delivers a blast of flue gases. The liner bend is accumulating fly ash, reducing draft as well.

    The Agency stands by its Qualification Test Results. The Statute of Limitations has expired.

    Case 2: Another 6″ Dia. Chimney Relining – Weil-McLain 368 Boiler with 7″ Exhaust Flue

    Here we go again! Same Town, a few streets away. Same installer? Wish we knew …..

    We were solicited for a planned, immediate boiler replacement. Customer lamented that existing boiler was rumbling and pulsating, running erratically since a chimney relining. Can’t imagine why ….

    Installed a Weil-McLain UO-3 with a Pressure-Fired Beckett NX Oil Burner, 6″ Exhaust Flue. “Runs like a top” …..

    Case 3: Our Duplex WGO-6, 400KBTUH Installation – Municipal Facility – Relined Chimney

    Existing 12″ x 12″ Brick Chimney was relined with a 12″ Dia. Stainless Steel Corrugated Liner to suit system requirement. The installer expressed frustration with the “scrape fit” install, then fitting into a 12″ Stainless Tee flue outlet, etc. Has an appropriate Chimney Weather Cap installed and has performed flawlessly for over six years.

    There are more than a few variables to consider in relining a chimney, if necessary. We have purposefully presented a trio of cases that exhibit a worst, a fixable and a proper case to show a progression of conditions to consider for your application.

    We are not Chimney Liner Installers, but we like yourselves have to specify them, live with them, or fix them. Always work from your appliance, current or planned to determine your requirements. You can get a little stretch by pressure-firing, particularly with oil, but doing it right wins every time.

    09/10/2020 P.D.M., Sr.

     

     


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  • HYDRONIC (FHW) HEATING OPTIMIZED – “Going Back To Nature?”

    Posted on by Paul Mercier

    A primary tenet of Industrial Engineering is: To properly justify a process change you first optimize the existing process, then define the proposed process and make your CBA’s (Cost-Benefit-Analyses) for both. From weighing these you will then derive your best course of action. Speaking from painful experience as a Manufacturing Process Engineer, you will make this mistake only once. Somewhere in a dark corner of a semiconductor facility (or hopefully a scrap pile) lies my personal ill-advised, sophisticated process equipment humiliation!

    The makings of similar embarrassments are appearing within the hydronics heating industry. Hydronic component suppliers can be placed into three primary groups: boiler, distribution and radiation providers. They correspond to the three basic elements of the hydronic heating process. Component suppliers define the scope and applications of their products within a heating system, but that’s all. History and physics now become excellent teachers.

     A century ago there were two competing water-based energy heating methods, Gravity Hot Water and Steam. Both were based upon the natural (gravitational) convection attribute of water in the liquid or the vapor state, respectively. Energy distribution from a boiler to radiation required no external energy, only variation of the fuel supply ….. more heat, more fuel. Powered burners and thermostats were added for control. Pumps (circulators) doomed gravity water by adding zone management while reducing costs. Thus the modern hydronic heating system evolved.

    I’ve had the benefit of “playing with pipes”, beginning as a teenager within our family heating business for over 65 years while pursuing a paralleled hi-tech engineering career. (You can’t raise ten kids even on an engineering day job.) So while doing hydronic work “on the side”, so to speak, hydronic evolution followed me. My “engineering hat” always questioned why natural convection shouldn’t be an asset rather than a flow-checked nuisance. The old “gravities” were so simple!

    Post-engineering “non-retirement” provided time to aggressively play with hydronics. My “motor head” also makes me analogize heating systems with automobiles, i.e. the boiler being a pure “heat engine” with air, fuel and ignition for example. So when the delta-t circulator came along, there’s the “automatic transmission”. Now what can we do with the drive-line (distribution)? Can we re-evolve the Model T Ford car as a hydronic “Model Delta-T Appliance” by incorporating natural gravity convection into delta-t distribution? Well, we can and we have …..

    The old Gravity Heating System featured a large boiler, proportioned larger piping and radiation, typically all cast iron and pipe. They were skillfully defined and installed, used no distribution energy and lasted almost indefinitely, a tough act to follow. Its modern contemporary uses a much smaller (albeit more efficient) boiler, features multiple, circulated zones with smaller piping and radiation. Arguably it trades off fuel efficiency and comfort convenience for some increased distribution energy and “sophistication”.

    The sophistication referred is almost entirely within the distribution element of hydronic heating systematization.This is the consequence of a component-driven marketplace, as prior mentioned. The contemporary build-in-place method of system installations relegates hydronic interconnection of boiler to radiation in particular as “The Plumber’s Playground” wherein there are few rules and little consequence. Every system differs in a similar application, and therefore all perform differently in practice.

    If the objective is to provide overall hydronic system energy efficiency including electrical power consumption, freelancing must be both qualified and quantified in practice. Redefining near-boiler piping to optimize natural (gravity) convection with the boiler and integrating a delta-t circulator to refine hydronic delivery dramatically reduces distribution material and energy usage. Our now-patented “appliance” exhibits a typical 8 to 13 Watts total distribution energy usage while heating, over 90% reduction depending upon the contemporary configuration. Coupled with a high-mass, cast-iron boiler to enhance gravity operation, it also exhibits a thirty-plus year economic and operating life, twice or more that of low-mass, condensing units.

    Further gravity convection enhancement is available within the appliance-to-zone interconnects. The “level & square, pipes everywhere” approach does not fly in a gravity world. Minimized, pitched piping to simple series and split perimeter radiation loops are ideal. Full port valving if necessary and fewest 90° fittings further contribute to minimizing head pressures and thus distribution energy consumption. It won’t win a beauty contest, but it will win the race.

    Our 2,700 sq. ft. personally built (1970) raised ranch home has been our gravity test stand. An indoor wood boiler was convection-coupled to the cast-iron, flow-checked supply and circulator returned 3-zone “oiler” back in 1975. Multi-mode, multi-fuel operation also permitted completely unpowered, manually adjusted flow check wood gravity convection heating. As an example some years ago up here in “Frostbite Falls, NH” we were powerless from a severe ice storm for 10 days. A mere inconvenience for us ….. just feed it wood and adjust the valves.

    We currently have a series of up to six-year installed appliance “Beta Sites” that have now aggregated over twenty-five years service with no system-related calls! Two oil-contamination incidents did occur and last year a power line short-circuit blew out every control on a system. Our appliance is comprised of all standard, domestic trade components, so it was restored within the day.

    Our “appliance economics” haven’t been mentioned but are profound. Very significant complexity, material/labor content reduction and extended operating life vs. traditional architecture eclipse contemporary materials and methods. This observation was similarly but subtly affirmed in the 2019 Annual Boiler Report by several contributors opining that in effect it’s still hard to beat the economics of a well designed and installed cast iron boiler system. Their commentary and our natural (gravity) convection appliance development experience confirm that the existing, i.e. the “pre-condensing” process has yet to be optimized, to our potential peril. But try to find trade journalism and process development efforts to the contrary!

    So, is history due to repeat? That is, will a hydronic “Model Delta-T” displace this industry’s “Carriage Makers”, or will there be yet another technical “skeleton” in my closet?


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  • OIL HYDRONIC HEATING IS CHEAPEST – For The “Smart” Consumer

    Posted on by Paul Mercier

    The assumption is that natural gas heating is historically cheaper than fuel oil, witnessed by the continuing conversion rate of oil to gas. The arguments forwarded are several, most notably that “natural gas (and propane) burn cleaner”, are “less expensive” than oil and therefore “more efficient”. All of these points are true in some context, but what is excluded has become significant to the discussion. Namely, heating system efficiencies and fuel cost differentials are narrowing the gap. Exactly how and by how much are the issues.

    An old New England adage comes to mind: “You can either raise the roof or lower the floor” to gain more space. Applied to heating you increase the efficiency of your appliance or lower the cost of your fuel ….. or do both, as we will contend.

    First, let’s begin by “raising the roof” of heating energy creation efficiency. Here again, hydronic (hot water) boiler efficiencies have increased significantly with AFUE Rating increases of over 10% for gases and half or less that for fuel oil. Good numbers at present are 95% AFUE for gas and 87% AFUE for oil “top end” appliances. More specifically these are Condensing Gas and Triple-Pass Oil Boilers, respectively. Now let’s get in a little deeper.

    There are three basic elements in any hydronic heating system:

    1. Heating water (a boiler),
    2. Moving heated water (distribution), then
    3. Heating the environment (radiation).

    The contemporary presumption is that the Boiler DOE %AFUE Rating defines heating system efficiency. This is patently untrue on its face. Distribution and radiation efficiencies must be considered to determine an aggregate value. Radiation by type and deployment also affect distribution configuration and complexity. The ensuing “middle ground” between the boiler and radiation we cynically denote as “The Plumber’s Playground”. Herein appears a relative maze of pipes, fittings, circulators, controls and wiring connecting A to B with artistic “free expression”. Thus that new, “pretty piped”, complex heating system despite saving some fuel is an electrical energy hog and a serviceman’s “friend”.

    A hundred years ago we had the Gravity Hot Water Heating System. It was utterly simple, had no moving parts and was operated by manually regulating a fire under the boiler. Powered coal stokers, oil or gas burners were later added with a room thermostat for automatic heating. It was abandoned upon introduction of the hot water circulator and zone valves for installation and operational flexibility and remains with improvements to date. However the natural (gravity) convection attributes of yore are present in degree within “modern” hydronic systems and must necessarily controlled with check-valving.

    Recent introduction of the Delta-T ECM Hydronic Circulator prompted and enabled us to effectively recreate a Neo-Gravity Hydronic Heating Appliance. Functionally it is akin to “putting an ‘Automatic Transmission’ on a Boiler”. Hydronic distribution energy is typically reduced by over 90% of contemporaries. Convective flow is finitely controlled by the Delta-T ECM Circulator like “paddling a canoe with the current” ….. virtually effortless! Coupling to a high-mass, cast-iron boiler to reduce burner cycling and system operating temperature increases boiler AFUE substantially, depending upon the site radiation and heating demands. These claims are substantiated within our U.S.P.T.O. Patent Submission, now affirmed by a recent Notice of Allowance. Canada to follow. Check out our website www.BoilersOnDemand.com for details.

    So, first upgrade your aging, less efficient boiler to a post-modern, high-mass, delta-t ecm distribution appliance, such as ours.

    Second, let’s “lower the floor” by changing your fuel oil buying habits! The “dirty little secret” is that you have options, many options. You don’t just keep buying from “Good Old Joe” because he’s nice and “takes good care of me”. Or pick an oil dealer out of the phone book, your neighbor recommends, or whatever. Not unlike automobile “gas station hopping” the oil dealers have a back door pricing system too, called Consumer Fuel Oil Co-Operatives. They typically aggregate fuel demands of their memberships and solicit seasonal quotations for heating fuel. To give a comparison, we and our participating customers have realized a 25 to 40% reduction over retail pricing in our area (S.W.N.H.) throughout this 2019-2020 Heating Season, for a $25 Annual Fee! Smarten up folks!

    Now, let’s dispel the notion that natural gas fuel is cheaper than oil, using our one-two strategy as detailed above.

    All heating fuels are rated by their “Cost Per Million BTU” as displayed in the NH Climate Audit Heating Cost Calculator, our personal choice of many available. We have used this calculator continuously since 2016 during our appliance development. In all but one winter cycle oil has been a cheaper heating fuel than natural gas. Oil has also eclipsed all other fuels listed for the past two years. This apparent natural gas discrepancy with oil must be first be explained.

    Natural gas and electricity are “distributed” fuels, i.e. they are necessarily delivered through pipes or wires to the point of use. Distribution and service charges are necessarily applied to these fuels, typically regulated by a State Utilities Commission. Therefore your actual bill is fuel cost plus delivery charges. Dividing the fuel cost into your total bill defines your Service Burden, expressed as multiplier of 1.x to 2.x. Our local multiplier is typically just over 2 at present. Therefore the Natural Gas Cost Per Million BTU must be multiplied by your Service Burden to obtain your true fuel cost.

    Oil and LP (Propane) on the other hand are liquid “delivered” fuels. You pay upon delivery and they are dropped into your oil or gas tank or as gas bottles in your yard. Similarly with the solid fuels: coal, wood & wood pellets. No additional charges apply. This distinction is very important.

    Playing with the Heating Cost Calculator, let’s load in 87% for oil & 95% for both natural gas & propane per prior. Load in $1.586 per gallon (our current “Co-Op Price) for oil & press “Recalculate”. Now using a side calculator multiply your natural gas price of 8.74 by your Service Burden. If its currently over 1.505 oil wins. (BTW – Pity that poor propane guy!)

    If you want to extend your heating calculator play time, increment the item cost values for coal, wood & wood pellets until you equate each to $13.15 Per MBTU. This is the item pricing equivalent to oil heating. Great stuff to needle your neighbor who’s “saving money” while trying to keep warm with solid fuels. Of course avoid that Old Yankee that cuts all his own wood “for nuthin” and massages his woodpile year ’round. “Heats ya twice, ya know.”

    It must be added that Condensing Gas Appliances are significantly costlier to install with reduced economic lives than cast-iron boilers.

    The Heating Blog on our website offers a wide array of related heating subject articles.


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  • THE 2019 BOILER REPORT – Reading Between The Lines

    Posted on by Paul Mercier

    Trade Journals are currently publishing the Annual Boiler Report for 2019. It is lengthy, detailed and provides tradesmen insight into both Industry Development and Regulatory Trends. Content and commentary is typically provided by Sales, Marketing and Product Managers of the various Boiler Manufacturers.

    Of particular note is the trend toward larger, commercial grade condensing gas systems and focus on advanced fire-tube heat exchanger designs. These new products are also being highly sensor-instrumented with interface optioning to IoT and Building Energy Management Systems. Further, industry focus appears to be upon gas-fired market development with no direct mention of oil throughout. However the inferences within the specific participant content need extraction and commentary.

    Industry Regulation of the Boiler Industry via DOE AFUE Requirements both current and projected are significant, well defined and discussed. Again the focus is wholly upon the Gas Appliance Market and the incremental impacts between 2020 and 2023, as interpreted. DOE has yet to become specific on Commercial Boiler AFUE’s and implementation points, but “residential gas boilers must have an AFUE of 90 percent or greater in all applications”. The new boiler efficiency standard will become effective in 2021.

    In this new world there will be effectively little gas-fired cast-iron in particular and with predictable consequence. This point is well reinforced in the report by comment of a major boiler manufacturer that “many customers are still looking for the long-term dependability of cast iron. When you really factor in everything from the cost of the boiler, installation cost, maintenance costs and life expectancies, cast iron is still a very sound choice”. Weil-McLain also weighs in: “Our legacy cast-iron lines have set the standard for performance and longevity with our high-efficiency lines continuing to lead the industry in innovation, operating fuel efficiency and ease of installation and maintenance”. Are we “throwing out the baby with the bath water”, to employ the old adage? The effect is to supplant in our view with a potentially less durable, but more sophisticated and costlier product. The marketplace will ultimately decide.

    “Products that can connect to a smart device and be monitored remotely is a heightened demand in the heating industry.” This is self-evident in the commercial sector and upscale housing where loss prevention can be outweighed by the added technology costs. In our personal experience the Wi-Fi Thermostat has widely infiltrated our residential consumer base. Witness a mid-winter night call from a customer in Pearl Harbor, Hawaii that his N.H. ski cottage had a temperature drop issue ….. using his cell phone and Wi-Fi Thermostat. To another we provided our oil boiler system with temperature sensor provisions to winter freeze-inhibit his outdoor wood boiler while he annually holidayed with family in the south. Consumers are becoming a savvy bunch and consequentially arrive at cost-effective system application solutions. This is well reinforced by a Boiler Report commentary that “adoption of new technology takes longer in the heating industry than in many other industries” ….. excepting “cool” customers?

    Technological boiler design inception is being tempered by the critical shortage of skilled trade personnel. “A large population of contractors are starting to reach retirement age and a much younger group is starting to enter the field.” Integrating gas boiler system elements such as hydronic expansion, circulation (internal and external), zone and system controls into their products is widespread in reducing installed costs and installation times. A major manufacturer states “we have opted to expotentially increase the number of training events both here at our facility and at locations throughout the country”. Our personal 60-plus year observation: residential heating installers in particular have never kept up with industry technology and it promises to not get better ….. technology far outpaces its proper application in the trades.

    Interwoven in the Boiler Report is commentary on “ours vs. theirs” offerings by boiler types, and most specifically the gas “Comb-Boilers” and their limitations. “One of the major drawbacks of a combination boiler is that you can only use one of the functions at a time, which can cause potentially uncomfortable situation for a homeowner.” This provider further advises of his “revolutionary design that allows for true simultaneous domestic and heating functionality”. This and other discussion support our field observation that misapplication of boiler designs to applications is evident in both gas and oil heating. Contemporary residential distribution piping practices in particular emphasize aesthetics vs. technical correctness. Witness the recent trade supplier “photo contests” to provide the prettiest workmanship installations. Nothing new ….. technology is misunderstood and hence misapplied.

    A common boiler provider’s theme is “design-for-manufacture” as we manufacturing engineers refer to obtain “economies-of-scale”. “We have components prebuilt within the factory.” The particular comment of “parts standardization across all manufacturer lines” may aid the individual boiler supplier, but there are very few common sensory and control parts in the emerging condensing gas industry in total. A Gas Heating Serviceman in a rural area (typically LP-Propane) cannot possibly stock nor have ready Trade Distributor access to boiler manufacturer-specific service parts. The customer is too often left cold ….. and angry! In fact it is difficult to find propane service by other than a Factory Technician, if that is even available. In the maturation process, the industry as a whole must address technical standardization and service issues ….. or stall.

    Underlying all these points noted from The 2019 Boiler Report is a more profound one ….. addressing the entire hydronic system installation methodology from a total system efficiency perspective. Other than providing a “Boiler Installation Guide” with generic piping and wiring installation diagrams therein, the residential heating industry ignores aggregate system efficiencies. The boiler (heating) industry sells components ….. not systems. The integration of distribution and control elements into new condensing gas offerings is commendable, yet a small beginning. Emergence of efficiency-optimized boiler/distribution gas or oil heating appliances at minimum are required. The system elements are there, but their evolution into particularly residential heating appliances will be painfully and historically slow …..

     

     


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  • WHAT IS A GRAVITY HEATING SYSTEM? – Gravity Convection Heating Revisited

    Posted on by Paul Mercier

    The three (3) basic elements of hydronic heating are heat generation (boiler), distribution of energy (pumps) and conversion to area warmth (radiation). Of these hydronic distribution is typically the least understood, generally misapplied and desperately needs revisiting!

    What is a Gravity Heating System? A century ago all water-based hydronic heating (hot water and steam) employed the natural gravity attributes of heated water and water vapor (steam) to distribute energy. NO DISTRIBUTION ENERGY WAS REQUIRED! These were effectively single-zone systems that could only be modulated by varying the energy input of the boiler and the radiation outputs using register dampers or steam radiator vents, respectively. Natural (gravity) convection of heated water underlies all hydronic distribution, yet is never considered in contemporary practice. So, check-valving is installed to negate its less desired effects.

    The introduction of electric circulation pumps in the 1920’s enabled forced hot water heating (FHW) and changed hydronics forever. Gone was the large, pitched piping and radiators, replaced with zoned heating and finned radiation. The heating market never looked back, and justifiably so. Lost however was “free” natural gravity convection effect that now had to be also controlled by using check-valving within the system.

    Early electric circulation pumps (circulators) were large, power consumptive and constructed of discrete components, i.e. motor to coupling to pump. We “old-timers” have vivid memories of failed couplings of varied types, seized and leaking pumps and smoked motors. The advent of wet-rotor circulators was like manna from heaven, reducing circulator issues with greater longevity and reduced power consumption benefits.

    Now the evolution and introduction of particularly Delta-T (differential temperature sensing) ECM Circulators projects hydronic distribution management to an entirely new level. The inherent integral instrumentation features and operational data display of delta-t circulators also provide us with finite attribute identification and application control.

    The focus of our work has been to optimize the innate, but hidden contribution of natural gravity convection as both a distribution energy saver and a selective fail-mode feature in hydronic heating. As such the Delta-T ECM Circulator has been the crucial tool in the development of our “Neo-Gravity Delta-T ECM Hydronic (FHW) Heating Appliance™” (U.S. Patent 10,690,356, Canada to follow). We claim optimization of natural gravity convection within our boiler, near-boiler distribution piping with distribution energy requirements using a single, dedicated Delta-T ECM Appliance Circulator. Citing an automotive analogy, we refer to it as “putting an Automatic Transmission on a Boiler™”. This intelligent, variable speed circulator is effectively a hydronic CVT (Continuously Variable-Speed Transmission) in practice.

    Let’s go back again to that old gravity hot water heating system of a century ago. By comparison, contemporary hydronic heating systems have smaller piping with multiple zones for heating flexibility. The old “gravities” employed high-mass cast-iron boilers with larger piping to modulate heating supply, otherwise control was particularly difficult when using solid fuel firing such as with wood or coal. Generous boiler sizing, distribution piping sizes and radiation elements gravity convection worked fairly well, and again with NO distribution power requirements!

    Properly piping a contemporary FHW system using a dedicated “Delta-T Mode” system circulator with complimentary low-energy ball-type zone valves vs. flow-checks yield great results! Transpose this configuration onto the old gravity system layout and you functionally emulate its performance as depicted in the following figures.

    The advantage is in applying natural gravity circulation to the contemporary upgrade. We have seemingly lost all trade skills in managing or enhancing gravity convection. No consideration is ever given to pitching, compacting and minimizing distribution piping in particular. Additional gains are available in radiation layout by using properly sized and configured perimeter series and/or split radiation loops. The 45° elbow fitting as an example saves 30% of piping and reduces head pressure significantly over a 90° elbow run. All this increased pipe volume and head pressure reduces the natural gravitational convection effect, not to mention increasing materials, labor and lifetime operating costs of the system.

    Our Delta-T Mode Circulator measures this head effect well via its wattage indicator. All of our single, dedicated system circulator Beta Site installs to date exhibit an 8 to 13 watt distribution power consumption with typical 4 GPM flow upon a 20° delta-t (adjustable) differential attainment. Compare this to 80 watts typical for each 16 gpm fixed-speed circulator or even 20 to 25 watts each for the new delta-p installs. With delta-t stabilization you can then witness circulation wattage steadily decay to half or less as natural convection contributes. We refer to this effect akin to “paddling your canoe with the current”. Takes a lot less effort ….. and power!

    A secondary effect of gravity convection seems to be radiation heating profile modification, smoothing demand amplitude variation and increasing comfort. Some of the extended fuel savings we observe and the delta-t manufacturer claims seem to be due largely to this radiation profiling effect. Another contributor is the lowered system operating temperature effect of using a very high mass cast-iron boiler vs. contemporary low-mass units. Burner operation cycles are also significantly less frequent than the systems they replace, increasing component lives and lowering maintenance costs.

    A personal cast-iron boiler observation: This author has never replaced a “cold shot” cracked or magnetite impaired cast-iron boiler in over sixty-five years of hydronic and steam installations! Perhaps a discussion for another day, but have we also “thrown the baby (cast-iron boiler) out with the bath water” to cite the old adage? Commentary in the recent 2019 Annual Boiler Report would seem to support our contention. Read our “reading between the lines” blog on this report.

    Finally, the combination of higher boiler thermal mass with enhanced gravity convection extends selective fail-mode heating continuity substantially. Recently and four years prior our Beta Site #3 experienced a fail-safe circulator interruption. The latter an over-current condition from a voltage surge “fail-safed” its operation. In both instances the condition was not discovered for an estimated 2 to 3 days, despite significant heating demand. Neither living area heating nor indirect DHW generation were affected. Second level heating reduction was eventually noted, as it was prior. The customer called and we reset the power switch over the phone to resolve. It is also noteworthy that we have had no system related service calls in over thirty aggregated operating years on our multiple Appliance Beta Sites!

    In closing, the contemporary excesses and misapplication of hydronic distribution are troubling to this author. If tradesmen are promoting their prolific  system distribution piping efforts as efficiency measures they are most sorely misdirected and possibly even deceitful. Witnessing customers proudly showcasing excessively installed systems or trade supplier contests for the “prettiest system” installation pics are also particularly disconcerting. Trade practices and hence consumer perceptions need challenging. Are we selling parts and labor ….. or performance?

    Perhaps it is time for our engineered “appliance” approach to rein in “The Plumber’s Playground©”.

    Updated 11/28/2020 P.D.M., Sr.


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  • HEATING A CHURCH – Warming Up The Congregation

    Posted on by Paul Mercier

    Heating a church is seemingly always a challenge. Whether it’s the structure’s physical attributes, the climate variations, the occupancy schedule and warmup demands, no two are alike nor can they be treated as such.

    Oh, to turn back the clock a few centuries when most churches including the Great Cathedrals of Europe were unheated! Shivering through a lengthy sermon must have certainly tested the faithful. However, we have become sensitive to our comfort in modern times including group participation in religious activity. “Passing the plate” to pay the fuel (heating or cooling) bill is particularly noteworthy to the congregation and usually a topic of comment.

    The scope of our discussion will be limited to and focus upon improved heating of a church (or similar structure) via enhanced air handling. In our experience most congregations have focused on cooling enhancement by adding ceiling cooling fans and employ them to more aggressively circulate air with or without air conditioning. Now revisit a church during the heating cycle ….. and the fans are still! Why?

    Heated air warms people, and eventually the structure. Seat yourself on a cold pew bench or metal chair when it seems that the air around you is reasonably warm and you will get the message. Add the practice of doing temperature setbacks between occupancy to conserve fuel (customary in churches and meeting places) and you aggravate the warmup process. Some of this can be alleviated with the use of Programmable and WiFi Thermostats, but even these cannot address the underlying issues of efficient heated air distribution, our topic.

    As simple and as obvious as it may seem, heated air rises! Any contained structure, heated or unheated, exhibits a higher temperature at its top vs. its base. Whether it’s a fully “vaulted” cathedral or an arctic igloo, the effect is measurable. No complaints from the choir loft in a cathedral, by the way! An extreme can be found in a high-bay warehouse where seasonal upper temperatures can reach above 140°F, an immediate personnel health endangerment. It must therefore become obvious that we must turn on the fan(s) to advantage the heating situation, but how and when?

    Most structures employ perimeter heating, i.e. placement of heating radiation or air registers around the exterior walls and usually positioned under windows where feasible. Heating radiation and heated air registers induce “convection” or natural rising and circulation of heated air, diffusing it with cold air emanating from windows and exterior walls to minimize their cooling effects. This heated and “mixed” air rises toward the centered ceiling or higher “cathedral ceiling” area creating natural convection and diffusion. Depending upon the individual structure attributes and aggressiveness of the radiation delivery there is always a level of lamination at the center/peak that can be advantaged by forcing it downward to mix and accelerate the heating process. The following pictorial is offered:

    Figures 1 & 2 above depict natural temperature lamination and convective flow of a perimeter-heated structure.

    Heating elements are purposefully placed against lower exterior walls to induce thermal convection while diffusing (mixing) with cooler air off the exterior walls for greater comfort. However, lighter heated air rises and accumulates at the ceiling levels, stratifying the air mass above. Cooling uppermost air gradually sinks and diffuses with lower, forming a midway convective path as depicted. Natural convection is never complete and the structure’s air mass is always significantly graduated temperature-wise from bottom to top.  The “vaulted” or “cathedral” ceiling in Figure 2 accentuates this condition, as coloring depicts. We must use forced convection (blowers or fans) to advantage ourselves.

    Our contention can be readily proven by switching on your present summer cooling fan(s), rotating to force air downward and adjusting until a modest air movement is felt. Turn on your heating thermostat and you will note a significantly quicker time-to-temperature resultant. The initially laminated air mass is diffused and then mixes with newly heated air to approach a more uniformly heated air mass. Ideally you should leave the fans on during the occupancy period, irregardless of thermostat demand cycling. It should be obvious that if circulation as described is not attainable, fan resizing and positioning may be necessary.

    Fan operation should be integrated into the heating system to maximize utilization and efficiency. The techniques must differ to suit each basic system type.

    1. Boiler-based Forced Hot Water (Hydronic) or Steam Systems are relatively simple to integrate. Trace the supply line from the top of the boiler outlet to the radiators or baseboard in the fan-located heating area.

    a. Place a heat-sensing “strap on”, “close on rise” aquastat such as the appropriate Honeywell 4006, 6006 Series on this supply line. Re-wire the power feed to the fans through the aquastat.

    b. Set the aquastat at 120°F as a starting point. Adjust in operation to suit. The lower the set point the longer pre-heat and post-heat fan operation to initially diffuse and then maintain comfort levels during cycling.

    2. HVAC Systems require a little more sophistication. Consult with a qualified technician to ascertain the proper strategy for lowering and lengthening system air delivery rates and timing.

    Note that an alternative control method is using a kick-space heater thermostat to switch a power relay such as a Honeywell RA89A (or other). Unfortunately the kick-space thermostats are typically available only in 110ºF (Low Option) 0r 130°F (Standard). However they can also be directly wired into an HVAC System, depending upon type. Commercial variants are available in different temperature settings as may be required.

    Using the prior technique another expedient is available. Purchase a common 24/7 Day Cycle Timer to dry switch the Honeywell RA89A Power Relay directly via its T-T (Thermostat) Terminals. Program the timer to approximate the 24/7 occupancy periods. Not as efficient, since intermediate heating cycles are not accommodated, but comfortable for the congregation. 

    Air lamination is an atmospheric attribute that must be addressed in all heating and cooling applications. Our scenarios apply not only to churches but assembly halls, public buildings and selective residential applications. In the end it’s cooperating with Mother Nature rather than fighting her.

     


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  • BIOHEAT® – “What shade of green” energy?

    Posted on by Paul Mercier

    Bioheat® is a blend of synthetic and distilled petroleum compounds being marketed as a “green fuel” alternative to traditional #2 Heating Oil. Functionally it is nearly identical to its transportation fuel equivalent, biodiesel. The two have been historically interchanged as a diesel fuel under controlled conditions, to the chagrin of regulators. Hence heating oil is dyed red to distinguish it from its “twin” and prosecute users to recover the taxes avoided.

    Bioheat® is currently labeled as B2, B5, B20 and B100, indicating the maximum percentage of synthetic “bio-material” content in each. You may be receiving B2 or possibly B5 without identification or knowledge, but the effects, both positive and negative, must be noted.

    Heating fuel oil is a less than ideal combustion product. It has contaminants included that reduce its operating efficiency, the primaries being nitrogen and sulfur. The “Specific Heat” of nitrogen effectively “steals” heat, reducing the combustion temperature. Sulfur generates less desirable combustion byproducts in sulfurous oxides that reduce atmospheric quality. Thus these “bio-products” are marketed as having a lowered sulfur content to improve our air quality. However, sulfur has a very desirable attribute that must be compensated.

    Sulfur is a natural lubricant that enables simplified design and operation of pump pressurized transportation and heating fuel delivery systems. Low-sulfur fuels reduce lubricity with predictable results ….. ask any older diesel trucker! We had a GMC P-30 Service Van at the time that “biodiesel” was being introduced. Our fuel supplier did not advise his customers of the change. One fill-up was all it took ….. a ruined fuel distributor and injector pump. We scrapped the vehicle!

    With the introduction of Bioheat® there is the presumption that the heating trade will incur similar introductory pains to biodiesel. This week we received a “New Product Notice” from The Beckett Corporation, the preeminent Heating Oil Burner Manufacturer, of a “Bioheat® Retrofit Kit” for their standard burners. They emphasize that B20 Fuel Grade Or higher) has still not yet been UL Approved, but their field issues prompt a fix for up to B20 only!

    Bioheat® and Biodiesel Fuels feature low sulfur content as promoted. They do not publicize reduced lubricity, nor the corrosive effect upon copper, nor the “cleansing effect” upon fuel storage and transmission components. The “Bioheat® Retrofit Kit” includes a new Suntec® Stainless Steel Fuel Pump and a Stainless Steel Pressure Delivery Line. What it does not address is the release and packing into all filters of fuel tank and line debris by its chemical “scrubbing”. To quantify the monetary impact we quoted the “Kit” with our Trade Supplier. In our New England Area we estimate a $250+ billing, installed. If it doesn’t get installed prior to the fuel changeover, a series of unexpected service events are predictable.

    Further suspicion must be directed to the lesser concentration cleansing effect of Bioheat® such as B2 to B5, not currently regulated. Older fuel tanks and systems in particular are susceptible to sludge accumulation that will be affected by any bio-concentration. The resultant will be accelerated sludge accumulation in both oil tank filters, supply lines, fuel pump screens, pressure lines and ultimately nozzle screens to operational failures. It falls to we trade servicemen to both advise our customers and monitor its effect on their system(s).

    All biofuel products directly address sulfur combustion products and their atmospheric degradation, a noble and necessary cause! However our emerging experience with a heating variation begs clarification of its effects and quantification of its costs. Our signalling the “Bioheat® Retrofit Kit” and its implications are only the beginning. Reviewing much of the available material from Bioheat® Promoters and suppliers, there is no economic impact, positive or negative, offered other than being “green”.

    The disallowing of any impact below B20 as stated in our view bears qualification.  Our development experience of The Delta-T ECM Hydronic (FHW) Heating Appliance (Patents Pending) has highlighted fuel quality and delivery as THE reliability factor in system operation. Our multiple “Beta Sites” are approaching twenty-five (25) system-years of aggregate, flawless system operation, marred by two (2) incidents of contaminated fuel delivery stoppages. Both were on replacement installations with prior existent oil tanks. We employ a Beckett NX (Low NOX) Burner exclusively. Unfortunately we cannot correlate these with a biofuel content, only that one incident was due to a mid-winter fuel drop issue. It becomes logically apparent that any biofuel content would have exasperated the situation. Our direct experiences have piqued our interest and commentary.

    To summarize Bioheat®:

    1. Bioheat® is a beneficial, environmentally “Green Fuel”.

    2. Its introduction and use bears operational and economic scrutiny, as it did with Biodiesel.

    3. The Consumer Economic Impact has not been quantified. The market deserves real numbers!

    4. Trade Personnel need to recognize its possible effects and adjust service maintenance to suit.

    Updated 01/19/2020 P.D.M., Sr.

     


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  • “THE HANDY HEADER™” – Building Block to Hydronic Distribution Efficiency

    Posted on by Paul Mercier

    Boilers On Demand LLC announces “The Handy Header™”, entitled “THE COMPACT STEEL HYDRONIC HEADER” within our Patent Submission. It is the first of several proprietary devices that contribute to the documented performance of our first, true Delta-T ECM Hydronic (Forced Hot Water) Heating Appliance (U.S. Patent 10,690,356 – Canada to follow).

    The “Compact Steel Hydronic Header” is a redefinition of the common welded steel-piped boiler header, optimized for hydronic performance and utilitarian value. Design compaction reduces the size and material content of current headers by approximately 40 percent while increasing hydronic distribution (flow) efficiency proportionally at minimum.

    Designed specifically to minimally space and orient Taco® “Zone Sentry” Valves, it supersedes the need for a Valve or Circulator Relay Panel on our Delta-T ECM Circulator-based systems. It has similar value on “conventional” heating system installations, however we are initially offering The Handy Header™ System only on our proprietary “Neo-Gravity Hydronic Heating Appliance” products.

    The “Compact Steel Hydronic Header” is the “building block” for a series of logical derivatives as follow:

    1. The Compact Header – The Base

    2. Zone Valve Assembly (Pre-Built)

    3. Hydronic Distributor (Pre-Built)

    4. Miscellaneous Applications

    The Compact Steel Header System is utilized on both our Modular Supply and Return Assemblies, configured to the Client Application.

    The Delta-T ECM Hydronic Distributor (our naming) is uniquely applicable within our larger, Multi-Boiler Systems. A series of these can be branched off the System Supply Log to suit extended installation requirements.

    Additional device announcements will follow upon prior qualification.

    Refer to our website BoilersOnDemand.com for additional details.

    Updated: 07/01/2020 P.D.M., Sr.


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  • USPTO NOTICE OF PATENT PUBLICATION – Paul D. Mercier, Sr.

    Posted on by Paul Mercier

    Pursuant to United States Patent & Trademark Office Regulations our Patent Submission entitled “ENHANCED CONVECTION, DIFFERENTIAL TEMPERATURE MANAGED, HYDRONIC HEATING APPLIANCE” is now posted for public access and viewing.

    A copy of the published application can be obtained at the following link, http://appft.uspto.gov/netahtml/PTO/srchnum.html.  Type in the publication number 20170299200.  Click “Search”, a link is presented to the published application, simply click on this link to access the published application html format.  To view the application as published click on the blue “Images” button at the top of the page.  Please note you will need an appropriate TIFF reader in order to view these images.

    We believe this to be the first, truly self-contained Delta-T ECM Hydronic Distribution enabled Heating APPLIANCE. It dramatically alters the installation of hydronic (FHW) heating systems as a free-standing, modular construction, application specific device. The installation task is reduced to merely positioning our Appliance and extending interconnect piping & wiring as necessary. Skill levels, installation and operational costs are significantly reduced with predictable system performance resulting. Interchangeable gas or oil firing options ….. same appliance!

    The proprietary items that support our claims beyond any contemporary hydronic heating installation are:

    1. Near-boiler piping configuration permits a “packaged” device, optimizing natural hydronic (gravity) convection with de facto Indirect Water Heater service prioritization.
    2. High-mass Boiler and Indirect Water Heater thermal capacities enable prolonged convection heating continuity under failed circulator or power burner conditions.
    3. Lowered system temperature operation and reduced burner cycling times for increased efficiency, extended system life with lower operating costs.
    4. All high-mass cast iron, steel, brass & bronze construction provides prolonged, natural chemical corrosion and thermal shocking resistance vs. all contemporaries.
    5. Proprietary components and assemblies enhance appliance operation and performance.
    6. A “Design for Manufacture” Appliance provides optimum consumer value.

    “Simple, Durable, Efficient FHW Heating ….. Period!”

    Within our Patent Submission are references to “derivatives” attendant to our product(s). These are being announced as our testing and sourcing is completed. Check our website for updates.

    Follow these links to our Product Sales Brochure and our website for additional detail.

    Author Note: Updated 12/14/2018


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  • BOILERS ON DEMAND LLC

    Posted on by Paul Mercier

    Be advised that as of April 10, 2017 Boilers On Demand is registered in the State of New Hampshire as a Limited Liability Corporation. We are classified as a “Manufacturer, Heating Equipment (non-FHA)”.

    Our mission is to provide our “ENHANCED CONVECTION, DIFFERENTIAL TEMPERATURE MANAGED, HYDRONIC HEATING APPLIANCE” (U.S. Patent 10,690,356 – Canada to follow) to the Residential Hydronic (FHW) Heating Market. We are naming our primary product the “Neo-Gravity Hydronic Heating Appliance™”.

    Fully integrating Delta-T ECM Hydronic Distribution Technology by Taco Comfort Solutions® with our proprietary near-boiler piping system enables a functional Hydronic (FHW) Heating Appliance. Further incorporating our lengthy experience with Natural Hydronic (Gravity) Heating built upon a Weil-McLain® UO Series (very) High-Mass, Triple-Pass Boiler provides a simple, durable and efficient heating system.

    Our modular, application-specific appliance capability provides the heating market with a value engineered alternative to the contemporary loose-piece, build-on-site trade practices. The predictable price-performance of a multi-fuel capable “Made In America” appliance is particularly attractive to the heating consumer.

    We are currently marketing our product via our dedicated website www.BoilersOnDemand.com to Fuel Dealers, Tradesmen, Contractors, Installers and Consumers within the USA and Canada. Extensive planning, installation and maintenance resources are currently available on our website along with a deliverable Power Point Presentation on our technological effort.

    There is now a real alternative in the Residential Heating Market and we encourage you as a consumer or trade participant to explore “What is a Gravity Heating System?”.

    Updated 08/29/2020 P.D.M., Sr.


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