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  • THE 2019 BOILER REPORT – Reading Between The Lines

    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 …..

     

     


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

    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 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 not 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. Underlying this however remained the natural gravity convection effect that had to be controlled using check-valving as noted 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. Integral instrumentation and operational data display of these circulators provide us with finite attribute identification and application control.

    The focus of our work has been to optimize this 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 “Delta-T ECM Hydronic Heating Appliance”. We claim optimization of natural gravity convection within our boiler, near-boiler distribution piping and distribution energy requirements using a 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 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” necessarily used high-mass cast-iron boilers to modulate heating supply, otherwise control was particularly difficult when using solid fuel firing as with wood or coal. With generous distribution piping sizes and radiation elements gravity convection worked fairly well, and with NO distribution power requirements!

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

    The advantage is in using natural gravity circulation in this contemporary upgrade. Today we have somehow lost the trade skills of enhancing gravity convection. No consideration is given to pitching, compacting and minimizing distribution piping in particular. Additional gains are available in radiation layout by using properly sized and configured 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 upon a 20° delta-t (adjustable) differential attainment. Compare this to 80 watts typical for each 16gpm fixed-speed circulator or 20 to 25 watts each for the equivalent delta-t or delta-p install. With delta-t you can witness the wattage steadily decay to half or less as natural convection contributes. We refer to this as “paddling your canoe with the current”.

    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 significantly less frequent and briefer than the system it replaced.

    A personal observation: This author has never replaced a “cold shot” cracked or magnetite impaired cast-iron boiler in over sixty 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 an old adage?

    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 twenty 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 excessive system distribution piping efforts as efficiency measures they are 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 ….. or performance?

    Perhaps it is time for an engineered “appliance” approach (as ours) to rein in this “Plumber’s Playground”.

    Updated 08/23/2019 P.D.M., Sr.


  • HEATING A CHURCH – Warming Up The Congregation

    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?

    Virtually all structures employ perimeter heating, i.e. placement of heating radiation or air registers around the exterior walls and usually somewhat positioned under windows where feasible. Heating radiation and heated air registers induce “convection” or natural rising and circulation of heated air by diffusing it with the cold air emanating from windows and exterior walls to eliminate 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.

     


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

    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 less than an ideal combustion product. It has contaminants included that reduce its operating efficiency, the primaries being nitrogen and sulfur combustion. 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 for.

    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 allowed that B20 Fuel has not yet been UL Approved, but obviously they are anticipating the inevitable. Our 60 years experience tells us that it is likely already here in degree.

    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 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 (20) 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, but 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.