• Tag Archives Steam
  • 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.

     


  • CONVERTING A STEAM HEATING SYSTEM TO HOT WATER – THE WHYS AND HOWS

    Steam Heating Systems were the Cadillac of heating options for residential applications for about a century. Pricey, tending to be a bit fuel-thirsty (regardless of the fuel used), they were extremely simple, durable and provided a superbly comfortable heated environment. Economics have gradually forced steam heating into the commercial and industrial process realms alone. So where do you go with that residential steam system? It depends upon your goals.

    When do you stay with steam rather than change over to hot water or some other heating form?

    1. If you have a nice, period home that suits your needs excepting to lighten up on your wallet a bit, just upgrade the boiler to a modern, high efficiency unit. Older boilers typically are large, with open heating passages to suit both wood or coal fires that when upgraded to gas or oil result in very poor fuel efficiencies. Presuming the system piping and radiators are serviceable there is little incentive to change over the entire system. (Steam heating distribution is arguably more efficient than hot water!)
    2. Similarly, if you like those decorative radiators that warm your hands, food, dry clothes on, etc. and take up less footprint and wall space than hot water baseboard, think again.
    3. If you plan an addition or heated area extension and envision running steam piping everywhere to heat it, there is the little known and utilized steam boiler “bottom water” forced hot water heating option. Circulating the lower water below the steaming chamber (top of the boiler) provides extended heating system flexibility. Furthermore, forced hot water extends capability to attics, garages and additions with baseboard, Unit Heaters (fan forced radiators) and Air Handlers (a ducted FHA Furnace with an internal radiator that heats your hot air vs. using a gas or oil fuel source). You must however convert zero-pressure steam water into approx. 15PSI heating water for circulation to new radiation. A correct plate-to-plate heat exchanger is required and circulation both from the boiler and to radiation added. A separate water supply source and an expansion capability must be provided for the pressurized heating water circuit as well. Note: Remember to size your now “two-state energy” Steam/Hot Water Boiler accordingly.

    There is an interesting “middle ground” where you can convert your existing, newer steam boiler to hot water operation while keeping those aesthetic steam radiators. You must however replace all the old steam system piping in doing so. Steam radiators work well with hot water, but at moderately reduced heating (temperature) capacity. More importantly is the higher water volume content of steam radiators and how to supply them properly for even distribution.

    Referring to our separate blog on FHW Heating Loops, you can’t pipe cast iron steam radiators in series and get even heating! Even a split loop will not work but for a couple of radiators at best.  The only effective option is the mono-flow loop system, branched for each radiator. All will require increased piping and circulator capacity.

    Despite the challenges, converting steam radiation provides some attractive opportunities, heating-wise.

    1. You maintain your prior heated area aesthetics and functionality with few perceptible changes.
    2. You can now re-pipe and “zone” the prior area with multiple thermostats, even down to individual room level if you desire.
    3. Obviously you can add additional heated areas (zones) as well.

    Fully converting a steam boiler to hot water operation and then replacing or adding all heating distribution components is the last and most complete option. Scenarios:

    1. You have an excellent steam boiler with an economic incentive in mind. If you just wish to swap this unit out for your existing, inefficient or failed FHW Boiler as a one-for-one, be careful. Make certain that the conversion components and labor (as applicable) justify the changeover.
    2. Changing your existing, older steam boiler to FHW in our view is questionable. You are trading off operational efficiency against upgrade costs.
    3. Steam Boilers typically and Weil-McLain Steamers (our expertise) in particular have several advantages over their sister Hot Water Boilers. The front and rear sections are notably heavier and bulkier, containing more cast iron and water that can contribute to durability and theoretically capacity. Can’t speak for other manufacturers, but the Weils are heavier and tougher. Check their Specifications. Also if you are using a DHW Coil (immersion coil in the boiler to generate your domestic hot water), steam boiler coil(s) have nominally higher capacities and larger (Weil-McLain) boilers sometimes have two coils, or provisions for them for greater DHW capacity delivery. Check.

    A recent phenomenon is the Outside Wood Boiler. You know, that thing that sits beside a house that looks like a Metal Garden Shed with a Smoke Pipe sticking up out of it and a woodpile alongside. They are typically owned by rural folks that have a great wood supply and don’t mind tripping through the snow to keep themselves warm. These boilers are also “zero pressure” systems. They must be adapted to a pressurized FHW System through a Plate-to-Plate Heat Exchanger, utilizing circulators and controls. (You must maintain constant electric service to these systems or it can get exciting and cold, or both.)

    Coupling an Outside Wood Boiler to a Steam System is dubious at best. The only deliverables in this scenario are preheated boiler water that must be then fired and converted into steam by the central boiler, but which can also provide DHW through its internal coil (if equipped) or by an Indirect Water Heater (Insulated DHW Storage Tank) as an option. It just doesn’t make sense except to generate a lot of Domestic Hot Water. Therefore, in order to utilize the Outside Wood Boiler effectively you must do a complete steam boiler conversion (or a hot water boiler substitution) with the appropriate scenarios as previously detailed. There is no “easy road to glory” on this one.

    So procedural, to convert a steam boiler to forced hot water operation you must:

    1. De-plumb all iron and other piping right to the boiler. It must be “bare” as we say.
    2. Remove all of the electric components and associated wiring.
    3. Remove the Boiler Jacket (usually sheet metal) and place aside for reassembly.
    4. First, locate and substitute a 30 PSI (FHW) Pressure Relief Valve for the 15PSI (Steam) Valve. VERY IMPORTANT! Forget, and you’ll get wet — and surprised!
    5. Remove the Water Sight Glass, LWCO (Low Water Cut Off), Pressure Switch, etc. (Clean off the front of the boiler, in other words.) Dope and plug all affected boiler taps.
    6. Check Immersion Coil (DHW) Gasket(s) and Blanker Plates for leaks. Fix them.
    7. The smart guy plugs, fills the boiler and pressurizes it to 30 PSI (until the Relief Valve opens) and then checks for ANY LEAKS! Remember, steam boilers operate at about 0.5 to 5 PSI in use. You may have sectional leaking issues and not see them at that pressure. Sectional leaks between boiler castings are usually catastrophic. Stop and rethink your options. But, assuming it passes …..
    8. Find the manufacturer’s boiler piping diagram and locate the preferred aquastat front tapping and insert the appropriate “Spud Well” to receive the aquastat.
    9. Reassemble the boiler jacket and provide the opening for the Aquastat “Spud Well”.
    10. From the Manufacturer’s Hot Water Boiler Manual, identify the control components and hardware necessary to refit. Present this info to your Qualified Heating Engineer or Technician.

    Pay particular attention that your Master Aquastat selection compliments your application. There are several operational options available and should be qualified prior to final selection. Our preferred is the Hydrolevel “Fuel Smart” 3250-Plus Aquastatwith “Electro-Well” for all conversions.

    You now have a tight boiler ready to reconfigure for your application. Your further risk is minimal, save a hot operation leak(s) that may or may not be seal-able. Now consult and utilize a knowledgeable source.

    Be mindful that in converting any steam system to forced hot water you reduce the capacity of that system by 10% or more, if that is a consideration. Steam operates at a significantly higher system temperature in its vapor state than can be safely achieved with heating water safely below its boiling point.

    It may be implied from the above that we discourage steam to hot water boiler conversions. We have done it very successfully, once with an almost new Weil-McLain Gold Steamer and we’ve never been back. Do your homework!

    The option of acquiring a near-new FHW boiler instead of converting your steamer, particularly with the preponderance of on-going fuel conversions can also make very good sense.

    Hope this has helped you assess your particular situation.

    Updated: 11/28/2018 pdm


  • TAMING YOUR STEAM SYSTEM – THE “HARTFORD LOOP” AND EQUALIZER PIPING

    In our preceding blog we addressed the subject “Plumbing Guys Plumb, Heating Guys Heat” to emphasize the need to employ complimentary skills in heating installations.

    Ironically, within a week of publishing we received a call from a new client complaining of “loud banging and water spurting out of the radiators” in a home they were to rent. A complimentary assessment and surprise followed that prompts this follow-up article.

    Apparently ten years ago a new, small, but adequate “plumber’s” steam boiler was installed to replace the original, large coal or wood boiler in the old farmhouse. The plumber exhibited good workmanship in “stretching the pipes” using copper and fittings to connect the new boiler, but obviously had no comprehension of steam heating, didn’t refer to the supplied Installation Manual requirements — or both. Explanation.

    Old Steam Heating Systems featured large water capacity boilers likely originally fired by coal, wood, etc. and necessitated by the continuous, lower temperature fires they utilized. The radiators, properly sized and positioned, provided nice, efficient, humidified and comfortable heating with that little hiss of venting steam. These boilers however were terribly inefficient, requiring firing attendance and water replenishment while consuming large quantities of cheap fuel.

    Conversely, new high-efficiency, intermittent and higher temperature fired (gas or oil) boilers are necessarily much smaller to provide the same output. Therein lies the problem. A ten-gallon boiler now replaces a fifty-gallon unit. All this size and water dampened and regulated the steam output of the “Old Dragons”. Now control has to be introduced to compliment these smaller “steamers”. (Also see our “Upgrading Your Steamer” Blog.)

    Every Steam Boiler Manufacturer in his “Installation Instructions” Manual details a boiler piping configuration known as “The Hartford Loop” and Equalizer Piping, whether so-called or not. Named after the Hartford Insurance Company that funded its development, it tames the modern steamers by preventing the overheated, split and sometimes exploding boilers resulting. Rather than expounding upon the Hartford Loop and Equalizer we refer you to an excellent article on MasterPlumbers.com entitled “What you should know about Hartford Loops” by Dan Holohan. It is well written and thorough.

    Now back to our misbehaving steamer. Walking into the home, it sounded like “The Anvil Chorus” being played by atonal blacksmiths with three-pound hammers both in the basement and on the radiators. Hot water spewed out of all the radiator steam vents even to the second level and all the floors were subsequently blackened by stains near them. Downstairs the boiler was surging steam internally, forcing condensate (hot water) up the supply pipes and back-flushing into the returns. Flash evaporation caused by driving steam through hot water created a cacophony of sonic noise throughout the basement. No water level was detectable in the boiler sight glass. The automatic water feeder and low water detector had apparently been fooled (thankfully) into overfilling and nearly flooding the boiler. This is the only thing that has saved this boiler (thus far) from destruction. (These sleepless tenants are the third in the past six months in this place — can’t imagine why!)

    This is undoubtedly the worst plumber-error installation we have seen to date. Most are more subtle with lesser impacts. It serves though to emphasize that utilizing appropriate resources is paramount to successful and ultimately safe heating system installation and operation.

    Steam system questions seem to predominate in our inquiries. There obviously is a deficiency of skills and understanding of steam heating, even within the heating trade itself. Hydronic (FHW) Heating has long ago overtaken Steam as a heating medium, whether wholly justified or not.

    Specifically addressing your steam heating system installation and operation, question the aggravations that may arise such as noise, water consumption, piping leaks, heating uniformity and fuel consumption. Anything beyond warm, comfortable heating with that little hiss from the radiators is abnormal. Enjoy your steam heating benefits!


  • STOP BABYSITTING YOUR STEAMER — UPGRADE IT!

    If there is anything to promote about a steam heating system is its absolute simplicity, reliability and durability. How many 50 to 100 year old boilers have we pulled that looked half that age and indeed much less? Can’t remember ever replacing a radiator. Fix a cracked fitting once in a great while (usually from someone banging into a radiator), pack a valve stem that is hissing. Usually it is replacing radiator vents that were hit, breaking the mounting stem or that have become stuck over years and the radiator doesn’t operate properly.

    Otherwise it is problems arising from bad water supplies and longer-term neglect that ultimately are the Achilles Heel of “Steamers”. Sludge and sedimentation accumulates untreated and then plugs particularly the return lines and obstructs boiler controls, and in particular affecting water level control.

    By definition, a “Steamer” consumes some water in making steam that must be both incrementally replaced and regulated in doing so. This can be done manually or automatically. The “old timers”, both residential and commercial steamers were replenished manually, hence the occupation “boiler tender” or “fireman”. Fortunately few manual examples remain, but there is yet an issue of reliability that must be addressed with “automatic” water feeders. Specifically the Float Style vs. the Electronic Immersion Sensor Style.

    An undetected and unregulated low water condition under a heat demand condition is the death knell of a steam boiler. Every failed steam boiler we have replaced, some as low as five years old has been “cooked” in heating jargon. The burner kept firing with low water until the top of the boiler castings glow red, then warp, seals fail and finally the unmistakable acrid smell of hot cast iron. This is always catastrophic and the first thing we look for is the reddish, rust orange color and dusting on the top castings. More importantly is why does this always occur with a supposedly “automatic” water feeder, specifically a “float style” feeder?

    The “float style” feeder is easy to recognize, typically an external, black casting extending from the boiler near the water sight glass that indicates boiler water level. Note also that there is also a handle on or very near the device with an open pipe or port used to move water through the float chamber, flushing out sediment and residue. This is a much overlooked feature and maintenance requirement of a steam boiler. READ THE MANUAL — IT MUST BE DONE PERIODICALLY AS STATED! Unfortunately if the feeder is ultimately flushed, even then regularly, the damage may have already been done by the prior negligence. The sure test is to shut off the boiler water feed, drain down the boiler using the boiler drain at the bottom of the boiler until the low water switch cuts off the burner circuit. Refill the boiler “automatically” and verify its functionality. Then repeat the test.

    Alternatively speaking, an Electronic Immersion Probe Low Water Cutoff is a “no-contest” option. Not only does it note low water, interrupting burner operation but can provide additional features, depending upon the individual model such as accurate foaming compensation, “settled down” water level delay measurement before and during operation, water feeder control and control external alarms. On the minus side the immersion probe should be periodically cleaned per the manufacturer’s recommendation. This can be readily done on your service cycle when the technician checks boiler water condition. Note: Many manufacturers now provide the Float vs. Electronic Low Water Cutoff Option in new boiler offerings. There are two (2) major cutoff suppliers, Honeywell and Hydrolevel, the latter being our personal preference. They can and should be upgraded to minimize boiler damage potential.

    Along with this must be considered the external “Automatic Water Feeder” itself. There are again several functional variations offered, ranging from a “dumb” turn-on-turn-off valve to more sophisticated programmable devices that can adapt to any system water usage, condensate return patterns and elimination of the resulting potential boiler “flooding” conditions. We obviously prefer the latter type. It compensates for all conditions during installation and eliminates any unnecessary future service calls. Our personal preference again is the Hydrolevel VTX Series Automatic Water Feeders.

    In conclusion:

    1. If you’re upgrading by simply replacing a steam boiler, specify an Electronic Low Water Cutoff System.
    2. If your existing boiler has a “float style” cutoff — retrofit it to an Electronic Low Water Cutoff System.
    3. In either case, also consider a Programmable Automatic Water Feeder.

    Save the gambling for Las Vegas.


  • WHAT TO DO WITH THE OLD STEAM HEATING SYSTEM? RUNS WELL, BUT THIRSTY!

    In the 1800’s steam was king! It ran the trains, industries, ships, heated the largest buildings and the finest homes. Steam heating continued in this respect into the early 1900’s to even smaller homes, providing distinctive styling and comfort to the American Lifestyle.

    Those beautiful Victorians, updated Colonials, Southern Manors, Seaside Mansions and latter day Bungalows were all heated by steam as the method of choice. They featured ornate radiation and huge central boilers fired by coal, cotton waste, corncobs, peat moss or wood — and lots of it!

    The age of cheap energy has passed and so seemingly the Age of Steam Heating ….. but not so fast! There is an old adage of “throwing the baby out with the bath water”, cautioning us to not dispose of the good to rid us of the bad. This aptly applies to steam heating in our opinion.

    The simplicity and comfort level of steam heating is unarguable. Those well placed, aesthetic and space efficient radiators emit both heat with a light hiss of escaping steam simultaneously heating AND humidifying our air. Room temperature can be reduced somewhat without a comfort penalty. To duplicate this environment requires mechanical creation using power humidifiers or more complicated HVAC Systems. (That’s also why common homes had a tub of water on the heating stove.)

    Three usage factors affect steam heating:

    1. Fuel efficiency. Those old steamers have heat exchanger passages and flue pipes intended for large, continuous combustion, low temperature fires that are the polar opposites of small passage, high temperature oil or gas fired systems.
    2. Installation or repair cost. Residential steamfitting is one of those fading (and therefore expensive) arts, it seems.
    3. Flexibility. Those big iron pipes don’t stretch or move readily. Extending a system seems formidable.

    Not so fast, again!

    You may have noticed that virtually nothing ever happens to the radiators and piping in your system — the distribution side of things. Yes, a radiator vent may stick so it can’t be adjusted. So you unscrew it (with the steam turned down) and replace it. A valve stem leaks, so you tighten or pack it. Unlike hydronic systems, no gurgling, noisy, tinny registers, circulators, relays or vents to go bad. Steam provides the absolute in physical non-mechanical distribution simplicity, efficiency and durability. This is the “baby” in our analogy.

    The “bath water” is that beast of a boiler — the dinosaur. This is where virtually all of the efficiency gains are to be had (plus a little smart usage). Additionally, this is where the third factor (flexibility) must be introduced and discussed in common.

    A steam boiler is like putting a partially-filled pot of water on the stove with a perforated cover over it to let steam escape in a controlled manner. When you turn on the stove the water rose in temperature until it generated steam. If you don’t need steam the water in the pot is still hot in degree and usable heat. There are therefore two usable components in a steam boiler — hot water and steam. As in past steam systems you can employ the hot water component to provide domestic hot water and additional forced hot water zone heating. So if you want to stretch your steam system to heat the garage or that added room, it’s available.

    That big iron hulk down there was designed with complimentary, rather large distribution piping. Hopefully at some point or through your efforts heat loss of the building has been improved. You don’t need the distribution size as a result. This is not necessarily a detriment, however. What is more important is to not under size the replacement boiler and it’s steaming time.

    As you create steam in a boiler, the boiler water level is reduced as steam rises throughout the distribution (pipes & radiators). Steam is condensed in the radiators giving heat, and this condensate (now as hot water) cools, slowly trickling back to the boiler. If you generate a lot of steam rapidly from a too small boiler, the water level drops quickly. The low water indicator feeds a quantity of new water into the boiler by design. Then the eventual returning surge of condensate “floods” the boiler, reducing or limiting its ability to create steam (heat). Make-up water management can be important.

    Worse, in the smaller boiler scenario there is also the danger of overheating the boiler to the extent that thermal shocking can be induced by replacement water, damaging the boiler.

    There are tricks to reduce these scenarios, but there is one guideline that works every time:

    Boiler Weight (Size) and Water Capacity = Performance Efficiency with Longer Boiler Life (Just look at the unit you are replacing.)

    We invite you therefore to compare the weights and capacities of Weil-McLain Steam Boilers with all of its competitors.

    If you are still determined to be rid of the old steam system in entirety, so be it. But save back those radiators. Don’t give your installer an extra payday.