Heating Help

good call

@ May 21, 2013 3:18 PM in The good old days and a Boiler Explosion

I had no idea either. What a great ad.

Christian!

@ May 21, 2013 2:06 PM in whatever happened to the development of a steam assoc.?

It's great to see you back!

I had drafted an email to you to catch up, and maybe give you a heads up on this thread, but didn't have time to make it brief enough, but I see that won't be necessary.

We've missed your eloquent, almost lyrical postings. But time does have a way of getting away, doesn't it?

I agree. An Ohio chapter would be of inestimable value to the association!

The good old days and a Boiler Explosion

@ May 20, 2013 12:35 AM in The good old days and a Boiler Explosion

From November 21, 1929.

Here's the link to the photo at a favorite website of mine, shorpy.com, Click on the picture for a very high res photo.

http://www.shorpy.com/node/15005

And an article in the Dunkirk (!) Evening Observer about it. Expand the image and the article is near the bottom of the fourth column.

http://newspaperarchive.com/dunkirk-evening-observer/1929-11-21

Which provides a reminder of the benefit of modern controls and also what evening newspapers were for.

Good question, Gerry.

@ May 19, 2013 6:58 PM in whatever happened to the development of a steam assoc.?

between you, Frank, Gordo, Dave, and a handful of others who do not necessarily post here frequently anymore or at all, there exists a significant preponderance of evidence that the steam heating medium can be both installed and operated in a very cost effective way. The choices of system styles is much broader than conventional wisdom suggests, and clear examples of low energy use also defy conventional wisdom.

My claim that boilers that actually boil and the generation of latent heat, etc requires a second look at the relationship between what is generally believed about combustion efficiency and systemic efficiency is falling on deaf ears, with the possible exception of present company. Judging and designing a system reliant on latent heat from the prevailing viewpoint of those who deal exclusively with systems that don't, puts us at an automatic disadvantage in my view. Especially in regard to keeping unoccupied spaces heated, a luxury that the future may not find sensible.

It has been claimed by a few detractors that our collective "anecdotal" evidence is not "real" evidence because, somehow, without the blessing of one "official authority" or another, "anecdotal" is a synonym for "false."

My dictionary must be different from theirs. Certainly devising a simple way to do what Steamhead has suggested a million times, that is, an "apples to apples" comparison of modern, right-sized steam heating systems in actual new construction. Officially. Whatever that means these days.

The minitube system in an older home with mediocre insulation should raise some attention and create some paradigm-questioning due to its remarkably low operating cost, let alone its lower installation cost due to its fundamentally small tubing size and simplicity.

The orifice vapor system with multistage boilers and firing rates for load matching in similar construction as above should raise some attention and create some paradigm-questioning due to its low operating cost and the fact that this is achieved with a "heritage" heating system.

But I can understand. A brick wall of institutional indifference can be very frustrating.

Philosophically speaking, I absolutely don't understand why, in a world of 7 billion people and a nation of 330 Million people and a much larger number of heating systems installed as compared to a hundred years ago or whenever, Why is there such a push towards monoculture of everything particularly in the choice of forced air and a similar monoculture in hydronic heating? Is it true that in an era where I would think we should have and field test more and varied choices that we're being boxed into a few choices of mega-culturally acceptable ways of heating our homes?

And that these choices are being further narrowed and enforced by the prevailing forces in the industry and their influence on regulators in government? And why must this new conformism to a particular form be so viciously enforced, especially by otherwise nice people?

I used to think we had friends here from the hydronic side of the fence, and from those who understand the merit of elegantly designed systems that perform beautifully without high complexity; that operate with low energy use but without a level of complexity that brings into question their sustainability or long term serviceability.

Our work in steam heat proves to me that it's a natural and legitimate counterpart to the momentum in the direction of increased complexity especially in the face of the nature and risk of rapid obsolescence before true life cycle energy savings may be realized.

I now suspect that our honesty in our revelatory observations is questioned, or worse, dismissed. I don't know if it is mere groupthink, or what. I won't question their motivations any more than I expect mine to be questioned.

But I thought we were all after the same thing. Economy, comfort, and the joy of creating such systems. Some of us steam types have proven to our own and clients' satisfaction that steam will serve economically with greater flexibility, simplicity and superior life-cycles. That it is a superior long term solution for a large number of circumstances.

And somehow this isn't news.

If a Steam Heating Association for the advocacy of the latest and best practices fails to get off the ground, I suspect it will be due to industry indifference. If it means that steam heating is suffocated at a time where the world needs it to be reborn, it won't be because of its real strengths or shortcomings.

It will be for reasons and motivations I simply can not understand.

sweating the details makes for pleasurable long term ownership

@ May 19, 2013 5:31 PM in This Week's Steamer Replacement

Great point about the boiler drains. Wimpy stuff.

I like to be able to "blow down" a boiler. "Dribble down" is just not a real alternative!

#5

@ May 19, 2013 5:17 PM in I have noticed more and more shotty work

All good requirements,

but

"#5- ISOLATION & ACCESSIBILITY- every component must be capable of being removed with out draining entire system . . ."

Good heavens, this is my biggest pet peeve. Well, that and badly piped steam boilers (which are everywhere).

Looked at a church with 5 large B&G flanged circulators. Boiler room piping all welded. NO valves anywhere. Can't isolate zone from zone or boiler from all zones. Need to replace a pump seal? PRV? Gage? Total drain down. Ugh. System is hybrid monoflo and parallel feed/ return. It took 6 hours to bleed the system!

They don't want to hear about putting in proper isolation, of course.

But back to intermittently occupied institutional settings

@ May 19, 2013 4:48 PM in What is the most effective heating system for Schools & Intermittent use buildings?

Setback is controversial only because each person presents one hard and fast rule for absolutely every situation.

This is a perfect illustration as to why HVAC is so much more complicated than it first appears. Consider 1) every construction type, thermal mass, insulation, height of structure versus its footprint, air exchange rate, etc; 2) heating medium i.e., hot air, water low mass, water high mass, water low temp radiant, water high temp convective, steam high mass cast iron, steam low mass convector, steam unit heater with blower, steam unit heater with blower as preheat to fresh air; 3) radiant heat surface available (none for hot air, a lot for low temp HW), emitter surface temperature, mass of interior surfaces (hard plaster vs drywall, or wood vs concrete), and resulting Mean Radiant Temperature viewed from the likely location of occupants, 4) heating system heat supply characteristics, i.e., single stage, multistage, modulating, multiple heat source (e.g. heat pumps with auxiliary heating elements); 5) number of zones involved; 6) occupancy characteristics.

7) Add to this the fact that assuming that it is statistically impossible to state that when a space has more than one occupant, that all occupants will perceive the same level of comfort!

So what specific setback temperature should be used?

Steam in an older structure that is of limited and predictable occupancy, is still the grand master of extraordinarily deep setbacks so long as boiler output can be matched to the real demands placed on radiators and convectors situated in a very cold space. Steam load under these conditions can be much, much greater than you could ever expect, which is precisely why it can recover so fast in institutional settings where boiler redundancy is common and very, very useful under these conditions. Besides, if there is a slight lag in Mean Radiant Temperature as people are arriving from outdoors for the school day, I've never noticed it because of the contrast of being outdoors first. Regardless, steam was made for just this kind of situation.

This is not the same as waking up from a deep slumber waiting for the house to warm up, where a cold toilet seat becomes an unforgivable shock to the senses! I'm sticking to intermittent institutional occupancy on this one.
---
Every other situation? I just tell people to take about a 25 or 30 degree day (or maybe 1/3 to 1/2 design temp in your area), turn the heat way down, and wait for an hour or so. In most older residences, you'll find that there's a sharp drop in temp first then a gradual drop thereafter, and even a point where the temp holds steady for a long time before dropping again.

The sharp drop is typical convective and radiant heat loss being uncompensated for. But that long period of steady temp is where your thermal mass comes into play. You probably don't want to loose that in a home with typical residential heating systems. So that becomes your starting point setback temp. Most any system should be able to recover from that without heroics. You conserve the heat in the thermal mass, but stop replenishing the heat that escapes quickly.

This is the best method I've found for determining a "coarse" temperature setback. It tells you a lot about the building. You fine tune from there based on the heating system's characteristics. And for temperature extremes? Especially those beyond design temp? For garden variety thermostats, I personally just cancel the setback and hold the temp a couple degrees below the normal occupied setpoint to limit the temp differential and then wait for that weather front to pass!

H.B. Smith

@ May 19, 2013 3:24 PM in One or Two pipe? Nice Radiator

That's an H.B. Smith radiator. It's related in style to their "x-ray" but is a little different. I've only seen that one once, in 1915 or so home about a mile from me in Lakewood, Ohio. That particular system is hot water. Very cool!

Ah. Found an old cell phone photo. You could orient them so many ways.

The Grand Master of Intermittent Heating is. . .

@ May 13, 2013 1:04 PM in What is the most effective heating system for Schools & Intermittent use buildings?

steam.

Intermittent operation, as found in older schools or churches, is steam's best territory, IMO. Remember that heir typical set backs were not merely "deep," but "OFF." Coal went out, and would be refired early in the morning. A modern steam boiler plant should (and often does) do precisely the same thing, but with some options for freeze protection.

There's nothing like supplying NO heat to a building with NO occupancy!

In NE Ohio, where I am, most schools' replaced coal with oil and/or gas boilers and are intentionally operated the same way. Well, they should be. One I'm familiar with uses older Hayes-Cleveland controls to modulate the firing rates and stage the boilers based on steam pressure feedback from the system. Around here, the rooms are all controlled with pneumatic modulating room thermostats. And vacuum return pumps on the condensate side. So should yours.

Maintenance or custodial staff arrives and hits the "GO" button and turns on the pneumatic thermostat air pump, and the system ramps up and fires at a rate and number of boilers required to develop a steam pressure consistent with the design of the system. Once the minimum firing rate is held for a specified time, the whole shebang shuts down until someone hits the "GO" button again, usually the next morning. Shutdown could occur awhile before students leave.

But how can this be, if the radiators, convectors, and ventilator/convector units are not unusually large, and why is there no concern for freezing of the heating lines? And how can a building with so much thermal mass heat up in 45 minutes?

First thing to remember is that any medium with a phase change and a huge latent heat capacity is going to act totally differently than one that doesn't. Don't let the fact that HW and steam both have boilers and radiators of some sort to lead you to think about them in the same way. And the need to get an intermittently heated building up to temp FAST requires a very athletic approach to heat distribution giving advantage to something that is both lighter than air and very intense. Every medium has advantages and disadvantages no matter what anyone says. In this application steam has a leg up on the others. Know where its advantages are and utilize them. Otherwise you're wasting a lot of potential and fuel.

So. . .

There are a few things I've learned about steam heating over the years that may shed some much needed light on how it best works:

• Steam is a dynamic heating medium due to both the vast quantity of heat required for phase change (with a 0 degree delta T in the process) and the volumetric change associated with it (about 1700 times). Refrigeration isn't a bad background for a steam heating engineer or tech. It gives you an idea how radically the amount of total heat transferred can vary (without temperature change!) due to ambient conditions, unlike water, air, or a box of rocks that you can use to merely shuttle heat around by warming it "here" and moving it "there."

• Temperature is not the same thing as heat transferred. A steam rad, convector, fan coil, etc. can condense A LOT more steam (and transfer A LOT more heat) into a cold room than a warm one, even if there's no temperature difference between the radiators of the respective rooms. The volume of steam drawn into each will be radically different, however.

• As steam flows through the mains it will dynamically change distribution patterns to favor a heat emitter in colder room(s) and/or one with the greater CFM of air flow through it, WITHOUT THE AID OF ANY ACTIVE CONTROLS WHATSOEVER. You really have to witness it in a larger building to appreciate it.

• Steam will heat up piping and radiation to full saturation temperature on contact, releasing latent heat and then "disappear" as a medium, leaving in its wake a trace of water, nearly a thousand times the heat one would expect from that mass of water and a powerful localized vacuum at the point of condensation. The localized vacuum created by the collapse of steam literally draws more steam from the supply. And this internal dynamic effectively "aims" the heat directly at the inner walls of the exchanger for highly effective heat transfer.

• Steam will heat up piping and radiation sequentially with a clear temperature line of demarcation at the leading edge of the steam "front." Steam mains must thus be considered as true manifolds and be treated accordingly with very fast venting and good insulation if any hope of even and timely heat distribution is to be realized.

• A steam heat exchanger can maintain full saturation temperature across its entire surface with virtually no temperature drop across it. Therefore, nearly 100% of total heat delivered to steam heat exchanger is transferred to the room air AND a steam heat exchanger can deliver more heat than forced hot water at the same temperature.

• Since virtually all heat delivered to the radiator is in the form of latent heat, actual heat loss along return lines is extraordinarily small as a proportion of that delivered to the conditioned space, even if the condensate return temps approach the steam temperature.

• Steam boilers are simultaneously evaporators and compressors. Radiators are simultaneously condensers and vacuum pumps. Therefore, their capacities need to match, and to match dynamically throughout the heating cycle. Matching can be accomplished with either a powerful boiler or boilerss that can be proportionally throttled, or by proportionally throttling (orificed radiator inlets or calibrated vents) on the condenser end of the equation. Preferably both. Obviously, room thermostats will quickly alter demand seen by the boiler, Responsive firing rates are a great match.

• Steam piping need not be large and heavy any more than hot water heating lines need to be large or air ducts need to be large. Steam need not be delivered to large radiators any more than forced hot water needs to be delivered to large radiators. So if there's supposed to be a vacuum return pump on the system, use it.

• Steam radiators, convectors, etc. can be a small fraction of the size required for forced HW to achieve the same heat transfer and mean radiant temperature of an exterior wall, etc. With small piping and small internal volume heat exchangers, the I=B=R steam pick up factor is unnecessary. For example, the SelecTemp system of steam heating, which used small refrigeration copper throughout, as revitalized by Gerry Gill and a few others here as "mini tube" steam heating, the boiler can be sized for the heat loss of the structure and not the radiation.

Other considerations that affect total fuel use:

• Since temperature and heat are not the same things exactly, stack temps on a boiler generating a medium with tremendous latent heat density (steam from water) are not precisely equivalent indicators of systemic efficiency as with those reheating a static, non-phase changing heating medium.

• Stack losses on gas or oil boilers can be MUCH higher than expected if fed into a cavernous chimney designed for very high excess air coal burners. Therefore, direct vent devices very often exhibit lower fuel consumption that's mistakenly attributed to their DOE or AFUE ratings. Proper draft management is a must.

• DOE heating capacity or I=B=R steam ratings as related to fuel input does NOT prove that steam systems are therefore 50% efficient, as I've heard some say.

And finally :

• There's nothing "green" about heating unoccupied buildings!

So getting back to old steam heated schools. Yeah they have a team of big boilers, but they only need run simultaneously at the beginning of the morning. And the heat should be off for all but about 8 hours per school day. Literally shut them down for weekends and holidays. At 6:30 Monday morning start pneumatic compressor, initiate the firing sequence, make sure the vacuum return pumps are ready to go, etc. By 8:00 AM it'll be 72 degrees in the classrooms. The boilers should soon be down to one boiler modulating on demand. The system should be off by about 2:00 PM, a little sooner on moderate days, a little longer on cold days.

If it's so brutally cold then the system won't shut down an that's a good thing since it probably could never make up that kind of temperature swing. ODR steam controls for non-intermittently heated buildings predict this and cancel set backs in unusually severe conditions. But most of the time you will enjoy huge temperature recoveries in no time and remember, once the steam all condenses, there's no water to freeze in the ventilator coils. Sounds efficient to me.

Wow!

@ May 11, 2013 7:51 PM in Hot Water to Steam Conversion

We had discussed that option a couple years ago in terms of converting or "downsizing" big single pipe systems!

And you would be just the person to try it since, well, it's not like we're loaded with new mini tube systems.

That's wonderful how well it works.

Air handler

@ April 26, 2013 11:23 AM in General Electric Air Conditioner

Air handlers like that could have been set up for general heating, or merely for reheat of chilled air or cool outdoor air. Restricted inlet pipe sizes would indicate reaheat or tempering (at least in my experience) A generously sized supply line would suggest general heat capability. A clue would be if there are sizable radiators in every room. If so, the coil is probably set up for reheat/tempering.

The importance lies in figuring the steam consumption of that coil.

If everything works right now, then measure the exiting air temperature of the air handler with the steam coil activated.

Then measure the diameter of the blower, and note the horsepower of the motor. From there, we can make some inferences as to the CFM of air being moved. This all assumes that there's no rating plate of any kind.

With specifics on CFM, inlet air temp and outlet air temp, there's a lovely formula on this site somewhere that will give you a pounds of steam per hour condensed by the coil. I should have it committed to memory, but when the mental fog rolls in, well. . .

One other thought is that if there's a properly sized air conditioning condenser unit connected to this, then note how many tons the compressor is. You can figure about 400 CFM per ton of A/C. Then that's your blower capacity. At least close enough for boiler sizing.

here: "CFM times Delta T (air, in degrees F) divided by 800. That gives pounds per hour steam. PPH= Sq Ft EDR divided by 4"

as posted in this thread- http://dev.heatinghelp.com/forum-thread/75962/Steam-coils-HELP#p810357

outstanding point!

@ February 25, 2013 5:29 PM in 2 boiler setup issues

I think many people just assume that all the problems that they associate with steam heat are really problems associated with a system that continues to operate reasonably well while malfunctioning!

MTC and owner's pocketbook

@ February 25, 2013 12:16 AM in 2 boiler setup issues

MTC said,

"The owner almost certainly wouldn't have gone for buying new controls for them, so I had to come up with a solution."

===

Now, some things pay for themselves over other options. New sequencing controls might do just that. On the other hand, Brainstorming and thinking about simple ways to get decent improvements in system operation are worth considering. As Yogi Berra once said, "You can observe a lot just by watching."

I think MTC is doing the right thing by carefully observing the actual operation of the system. A lovely PID controller installed by someone who hasn't analyzed the actual system operation could be wasting everyone's time and money.

Obviously, availing oneself of a more sophisticated boiler operation logic is preferred. But only if it is applied correctly. Myself, burner modulation is a must, but I rarely get that either. An intelligent work-around can be something to behold if the person/people paying the bills are penny wise and pound foolish. If they are hopelessly cheap (and I don't mean poor- I help them out the best I can) then I fire them as my client!

Should the building owner want to spring for one, a Heat-Timer SQ could be considered. I have some experience with this control, but have only used it in a 1.5 - 2.5 psig system with a couple of steamers with lo-hi-lo power burners. It utilizes PID logic, but can also compensate for oversized systems. It will resolve to fractions of 1 PSI, and even vacuum, if you use the lowest possible (15psi) sensor. You can program just about every parameter of system operation.

Should the budgetary situation change or if the building owner can be convinced that such a control can improve comfort and efficiency if properly installed and programmed based on the system's actual characteristic behavior, then it's the way to go.

http://www.heat-timer.com/zhFiles/ProductDocument/manuals/SQElite8S059076B.pdf

yes

@ February 24, 2013 3:57 PM in 2 boiler setup issues

You've got the idea! If that works to adequately prevent a lot of cycling on the 2nd boiler, go with it!

Your way also prevents the system from sending false feedback to the boilers due to bad venting. In other words, if the venting is inadequate, the system can reach the cut off pressure of the 2nd boiler early in the cycle because two boilers can expand a lot of steam into the system, perhaps faster than vents can let the air out. Should one boiler permanently shut down because of this, rather than genuine steam circulation, then you may as well have not started the 2nd boiler to begin with.

As for myself, I tend to write notes on tags for anyone and everyone getting anywhere near the boiler to see, explaining what's adjusted and why. So if I get hit by a wayward chunk of asteroid, at least the steam system will remain unmolested. Since I started doing that, no one's ever touched anything and it seems the clients like it well enough that they keep me on. And I haven't been hit by an asteroid yet!

Do you think

@ February 23, 2013 11:56 PM in 2 boiler setup issues

Do you think the first boiler could handle the load if the 2nd boiler was allowed to drop out completely after the pick up load is satisfied?

Without modulating burners, you're just going to have a lot of short cycling on the second boiler once the pressure starts to rise.

It seems to me (without further details) that boiler 1 is a bit short of handling the pickup load and therefore runs without really distributing the heat evenly. The outdoor thermostat on boiler 2 could work if it were a hot water system, but steam doesn't work that way. Remember, steam heats sequentially, so if the boiler is short of actual load conditions, cold radiation tends to stay cold, and warm areas of the building tend to overheat.

So running both boilers initially on each cycle will distribute the steam, and once distributed, might work fine.

Here's an experiment you could try: On a cool start, run both boilers. Set the vaporstat on #1 to about 12 ounces, vaporstat on #2 at about 10 ounces. Once boiler #2 shuts off on pressure, power it off and se what happens. If heat continues to distribute evenly and satisfy the call for heat, then you might consider accomplishing this elegantly with some simple relay logic, or more crudely (and perhaps more effectively) with a simple adjustable aquastat on the return line or condensate receiver.

So, the first thing to know is if the first boiler can carry on once the system reaches saturation.

A boiler sequencer would be nice but the modern electronic ones operate on pressure sensors that don't seem to resolve in the Vaporstat range.

I've worked with several of these systems.

@ February 23, 2013 11:00 PM in Two pipe Air vented system

I've worked with several of these systems.

The returns are usually dry until the boiler room. The returns can fill with steam, but really shouldn't until a little later in the cycle.

Some things to remember about these:

The returns must NOT be vented;
The main usually isn't vented in my experience, but if so, its drip must be isolated from the return thru a water seal or float trap (NOT a float & thermostatic);
The pressure must be low, like no more than 1 lb or so.

If the returns are vented, plug the vents. If they drop into a vented condensate receiver, then you must trap the return with a float trap (again, no venting!) or a fairly low false water line. [I've plugged the thermostatic element on F&T traps in this situation with great results. But you didn't hear it from me! ;-) ]

Just look for thermostatic air vent traps that will either "short circuit" the steam into the returns or vents on the return system. Keep the pressure low and you should be good to go. These systems work fine when treated right!

if I'm understanding this correctly,

@ February 20, 2013 6:59 PM in STEAM COMING OUT OF A CONDENSATE PUMP

you have one pump attached to a vented return tank (condensate receiver) of some sort. The pump on the vented tank is operated on a call for water from one or both boilers and the solenoid valve chooses which boiler gets the water.

If this correct, my guess is that the tank is sitting on the floor with its water line considerably below that of the original installation's water line, originally being at the prevailing water line of the original boilers. I think the return was originally "wet" with the return well below the boiler's water lines (fully immersed in water) and kept that way by being directly attached to boilers and subsequently held back by the steam pressure pushing down on the boilers' water line. It seems that now the return goes "dry" as soon as there's enough pressure in the system because the vented tank has broken the line of communication from the boilers backward into the return system.

Long and short of it is that I think you need a false water line. Instead of a P trap, you need a tall upside down version of a P trap with a thermostatic float type air vent on top. There may be something on this subject in the "Library" of this site, but I know for sure that it is covered in Dan Holohan's "The Lost Art of Steam Heating" available here in the shopping section. There it will explain what has gone wrong in your system and how a false water line brings the water level in the returns back to where they should be, keeping the steam out of the return system.

Boy, that 2nd extra cup of coffee

@ February 19, 2013 5:23 PM in Steam Pipe Coils and Sprinkler Heads

made more jumpy than usual today. Sorry for being quite so defensive!

And it's a good heads-up. I would have advised the same. There's so much liability today even when things don't go badly wrong. A little unplanned flooding? EEK.

Seems the only guys who get away with it are the ones who patch in their water heater gas lines with a garden hose!

Thanks again for your input, Paul!

Let me see if I'm getting this right.

@ February 19, 2013 5:01 PM in New meets old

This is a single pipe system and they're going to fan-coil everything and expect the coil to vent and drain into a single riser? How are they proposing to vent the coils? How are they proposing to stop the steam when heat is not required? And is one fan coil supposed to take the place of multiple radiators? If so, is the riser able to handle the load? And is the riser able to supply enough steam to the coil in the event of extremely cold make-up air? if not, the coil will suffer "steam stall" and probably freeze. Steam stall is when the steam is condensing so quickly that the supply of steam is inadequate, the "vacuum zone" falls somewhere in the middle of the coil and condensate fails to drain due to the vacuum holding it back, all the while ice cold make up air is blowing across the coil and potentially freezing the coil.

If they don't know what they're doing, everyone's going to be in a world of hurt when the whole thing has to be repiped.

Edit: rereading, this is a two-pipe with Paul vacuum air vent system? Wow. They're going to have to put an air vent at the top of the F&T, but I think that thermostatic element will get hammered to smithereens by steam existing in the return. They're going to have to valve it at both supply and return for control, and assure that there's a vacuum breaker to prevent the coil from vacuum damage.

And all this and they won't have any more radiant heat provided by the cast iron.

ANd you're right. The blower will blow cold between cycles.

The only way I've seen this work with continuous blower operation is with a continuous steam supply to a modulating steam supply valve on a real two pipe system. Best yet is to allow the fresh air to be modulated both on heat demand and outdoor temperature.

So they probably should drop new returns into a dedicated vented condensate receiver/pumping unit.

Dunno what they're going to do about all the cold air between cycles.

I have no intention of touching a sprinkler system

@ February 19, 2013 3:34 PM in Steam Pipe Coils and Sprinkler Heads

with a 10 foot pole!

I just want to educate myself a little on this one before the experts come in who want the owner to replace the whole sprinkler system or something. Where I live, it is best to a least be somewhat familiar with the probable answers to a question before calling someone in.

I'm a steam guy, and have dedicated myself to "best practices" in steam work but not "most expense practices." I go to bat for my clients to protect them from charlatans and gougers. I always look things up first, and this is why you don't see me pestering the "Wall" with a zillion questions, if ever. But this one threw me a little, since it is not a common question.

So thanks for your input, but gosh I feel strange having to defend myself and my professionalism.

So off to the fire marshal I go. Unless this guy comes in to answer the question:

Dan, I was thinking about the air temperature myself when I first considered it,

@ February 19, 2013 2:19 PM in Steam Pipe Coils and Sprinkler Heads

but the photo is misleading. I think the sprinkler head is only about 14" away from the coil.

This is the kind of thing that keeps me awake at night. As a matter of fact, this potential problem woke me up the night after I told the building owner that we could hook the coil back up again on a motorized zone valve.

So I put the coil on hold until we have a definitive answer.

I hate it when I have to say, "Sure, blame the guy who. . ." when something happens as a consequence of what I have done, you know, like buttering the kitchen floor or melting the snow on the porch steps with boiling water (when it's 20° outside).

Thanks!

good idea.

@ February 19, 2013 2:09 PM in Steam Pipe Coils and Sprinkler Heads

I think the Fire Marshal is a good idea. And I wouldn't get too too upset about using two to's in one sentence. Caesar used only one (et tu?) and it got him assassinated!