Best Boiler

Wendell

Developed a leak

above the water line. It was run at three pounds of pressure for almost 20 years. The old man liked it nice and warm too. Just doing our part to warm up the planet!



Charlie, did you get a picture of the leak?

BRIANJ

The slits

Those slits are similar to the size of the holes in the Broomell quintuple valve. The number of slits or size of the holes in the Broomell orifice were designed to the EDR of the radiator. I have to assume that the sleeve with one slit was from a small radiator and the 4 slits from a very large radiator.

If your boiler doesn't have a high-lo-high gas valve you may want to look into installing a two stage valve for lower pressures. I had one installed on my system and it now runs at 1.5 ounces of pressure and saved me about 30% off my gas bill. Also, the heating is extremely comfortable and quiet.

Wendell

Two of my ten radiators

are the same size (bath and small bedroom). The bathroom radiator has an extra slit. It appears that slits were added or removed to fine tune the system.



I don't have a low pressure gauge, but if I slowly turn down the vaporstat (with hot radiators and full steam) it trips just under 2 ounces. Charlie has it set to 6. If I close half of my radiators the vaporstat will finally trip at 6.

Wendell

Lucky find...

Cleaning out my basement, I found a brand new mercury thermostat for a 24V system (original box and instructions included)!

ChrisJ

anticipator

You need to change that anticipator setting.  Bump it up to 0.8 or 1.2A for your boiler.  You have the vent damper so 0.8A is technically currect for your setup.



I decided to go with 1.2 as it allows more temperature variation, but the boiler runs fewer times per day.  Not sure if yours goes higher then 0.8?  hard to see in the picture.



By the way,  I like the wood behind the thermostat, looks good!

Wendell

The wooden backing is

a piece of mahogany scrap. I installed it to seal off an annoying draft. Our house is an old Cape that consists of brick, air space, and horse-hair plaster (there's not much in the way of insulation).



When winds blow from the northeast, chilled air vents through the thermostat. The backing plate has stopped it.



I'm attempting to fully saturate the radiators by fiddling around with the anticipator. It seems to be working and is somewhat easier than adjusting the closest radiator. There are no traps on my two pipe system. Just oversized radiators that condense rather well.

Wendell

Fiddling with the anticipator...

I think I've saturated my radiators.



33 degrees outside.



Gas boiler pre-heats for 11 minutes.



Steams for 22 minutes longer (average total run time of one half hour).



Radiators reach 198 degrees and return lines near the boiler are barely warm to the touch.



The boiler stays off for just over two hours.



Thermostat on at 70.1 degrees, off at 71.3 with residual heat peaking at 71.9



Is this a reasonable cycle for an un-insulated brick Cape?



Edit:

129K BTU/Hr, 1950 square feet.

Dave in QCA

Why

Why do you want to fully saturate your radiators?  By that, I assume you are saying that you want them to fully heat up and be full of steam. 

In mild weather or when there is not a high demand for heat, this will cause over heating and swings in room temperature, discomfort, and wasted fuel.

It is normal for radiators to only partially heat.

Dave in QCA

2 degree swing

The problem with a 2 degree swing is that the beginning point is likely to feel too cool and the ending temperature is too warm.  You indicate that the boiler is off for a little over 2 hours.  One cycle per hour is usually considered optimum in that the cycles are not so short as to fail to distribute steam equally, and the are not so long to cause swings in temperature.  A nice even heat, where you don't notice if your boiler is running or not, is what you want.



The purpose of the anticipator is to anticipate the heat that is going to come into the space from the heated radiators, so that it will shut off the boiler early and avoid wild swings in temperature.  You should set the anticipator so that it does its job properly.  What you have done is to set it so that it is not doing its job at all.

Wendell

Just the dog and me

Thanks, Dave. It's just the dog and me and we don't mind the swing



From an efficiency standpoint, I was thinking it's better to saturate the radiators between cycles. That way, I'm only pre-heating once every two hours vs. every hour. The pre-heat is a little shorter when done on the hour, but not by much.



Still not a good idea?

ChrisJ

What is cheaper with steam?

A really long run cycle less often, or more short run cycles?



I have my system setup right now with the anticipator shut off and my boiler runs every 3-4 hours or so. Sure I get a 4 deg temp swing, but no one seems to mind.



I assume this is technically more efficient as the boiler runs longer, which I thought highly effects its AFUE rating?

Mark N

Efficiency

The longer the boiler runs the more efficient it becomes, if it runs all the time it has no standby loss and you have a very high gas bill. Don't confuse your boilers combustion efficiency with the overall efficiency of your steam heat system. The hotter the water is in the boiler the quicker you'll make steam. The hotter the pipes are the quicker the steam gets to the end of the main and the rads. Lets take a look a 2 boiler runs where the boiler runs for 30 minutes. In boiler run #1 the system ran just an hour ago, after 10 minutes you have steam to the end of the main and at the valve of all the rads. The boiler then runs another 20 minutes heating the rads. In boiler run #2 the boiler has been off for 3 hours and it takes 15 minutes to get steam to the end of the main and at the valve for the rads. The boiler then runs another 15 minutes. In boiler run #1 2/3 of the the heating cycle was heating the rads, in #2 it was only 1/2. I would think the # 1 is a more efficient cycle than #2, more of the btus went to rads and not to heating the water and the pipes.

Mike Kusiak_2

Maybe...

Mark, what you are not taking into consideration is the standby losses. Lets think about the two extreme cases. First, say your boiler runs and generates steam only once per day, the rest of the time it sits cold and idle. When cold there is no standby loss at all since the boiler and piping is at room temperature. Now consider the case where the boiler runs constantly, so it and the piping are always at steam temperature.  The boiler and piping are constantly losing heat to the uninsulated basement, relative to the heat transferred to the radiators heating the occupied space





Its really the same argument as whether setbacks save energy. Does the reduced heat loss of the lower setback temperature more than compensate for the amount of energy needed to bring the building back up to temperature? It may depend on the particular case and how the system is configured.





So may also be the case with the length of steam cycles. If the boiler and piping is poorly insulated, the corresponding heat loss may be considerable, and long cycles with long off periods may be more efficient. If they are well insulated and the heat lost from then is small, then it might not be significant in terms of total system efficiency. The increased comfort of the shorter, more frequent cycles may be better, since a lower thermostat setting can be used.

crash2009

Hi Mark

Run #1 is 30/90 and Run #2 is 30/210.  Run #1 will be running around naked, and Run #2 will be running for a sweater.  After thinking about it for a minute, I guess it depends on the building.  A drafty old shack like mine likely needs 30/90, whereas if we gutted it and tightened it up to the max, we probably could get away with 30/210









 

Wendell

Good points, Mike and Mark

Looks like it boils down to individual systems.



I took accurate notes as to the temperatures and run times on a rather still 32 degree day. The northeast is warming up this weekend, so no more testing for now.



When it drops back to freezing, I'll change the anticipator to an hourly cycle and record the results. Ill report back on total run times for both one and two hour cycles over a 24 hour period.



-Wendell

Mark N

Standby Loss

Mike,



It is my understanding when a Boiler runs all the time there is loss up the chimney and out the jacket to the basement, but I don't think that is considered standby loss. Standby loss is the heat lost in between cycles. I would think in your scenario # 1 the standby loss is 100% all the heat has been lost, the boiler cooled back to room temperature. When it runs all the time it never can cool back to room temperature thereby no standby loss because it doesn't turn off.

Mark N

For Discussion Only

Crash,



The examples I gave were for discussion only. I myself set my thermostat for comfort, I have a Honeywell FocusPro 5000 set for I cph and the temp at 70 for the whole winter. The point I was trying to make from my own observations is, the hotter the system is when it starts the more efficient the overall cycle will be. More of the BTU's end up in the rads and not heating the water and the pipes.

crash2009

Mark

Yea, I know you were just making the examples extreme to make a point.  But what about these guys that say that it takes a relativly small amount of btu's to raise water temp from 70 F to 212 F and a large amount of btu's to go from 212 to steam?  If its inexpensive to get the water to 212 then why not let it cool before we heat it then?  If I had only known that before I insulated my returns, I could have saved the cost of the insulation and not worn out the knees of my jeans.

The Steam Whisperer (Formerly Boilerpro)

Something else to consider

Is how the sytem interacts with the home.  Yes, long on and off cycles are best for the efficiency of the boiler and probably re stand by losses, however, ever consider what happens when you saturate a space with heat?  You typically end up with extremely high temperatures at ceilings, which creates very high losses through the exterior surfaces and creates very high stack losses through the living space because those very high ceiling temps greatly increase air leakage.  Elimnating this waste is probably one of the biggest contributers to the savings when using outdoor reset on hot water or steam systems or the use of high mass emmitters, which largely mimic outdoor reset.

ChrisJ

I wish

I could set for comfort but for some reason my Honeywell T87F doesn't seem to care about my comfort.



If I set the anticipator for .80 as per my boiler manual it shuts off too soon. .90 is the next step and then the contact is essentially off of the rheostat. I'm trying the .90 setting now.



Its as if the anticipator doesn't take 'time to steam" into consideration which obviously will vary greatly depending on outside temperature and what not.



I'm really considering buying a new round digital honeywell because I like the looks. It also offers the 1 CPH setting. Something I don't understand is why do modern digital stats have a CPH setting and no anticipator if they are not the same? Is it because a digital thermostat is more accurate and quicker to react so it doesn't need an anticipator?

crash2009

Had to look it up

to get the numbers right.  One pound of water at 70 F, plus 142 btu's, equals one pound of water at 212 F.  One pound of water at 212 F, plus 970 btu's, equals one pound of steam.  I agree with you, if we try to keep the water, as close as we can, to 212 F, then we would save part of the 142 btu's, that we would have used, if we allowed the water to cool.  Maybe not all those 142 btu's are lost though, some of them must be absorbed into the building.

Mike Kusiak_2

Standby loss

Yes, you are correct in your understanding of standby loss. Perhaps what I should have said is total "parasitic" losses consisting of standby loss and jacket and piping losses. While firing the boiler, standby loss is zero, but piping and jacket losses still occur. When the system is cold there are no losses of any kind.



So, if the boiler fires 100% of the time you still have constant losses, whose practical effect is to heat the basement rather than the living space. Except for flue losses, which can be minimized by an automatic flue damper, the heat needed to bring the boiler and piping up to temperature is not really "lost". Rather, the heat is lost to the basement which typically is not considered part of the occupied space. So a good method to see how efficient your system operates is to compare how warm the basement is compared to the living space. The cooler the basement, the more efficient the total system since a greater percentage of the heat generated is actually going to where you want it.

Mike Kusiak_2

Anticipator

AS I recall, the anticipator settings are continuous in nature on the T87, rather than in discrete steps. Have you tried setting it between the numerical markings?



Digital thermostats achieve the anticipator function by a mathematical algorithm. They measure how fast the room temperature rises during a call for heat and then sees if the final temperature overshoots the setting after the boiler shuts down. From this data, it then calculates when to shut off the boiler early, so the final room temperature agrees with the setting.



The CPH adjustment determines how long after the last call for heat the next cycle can occur. It does not automatically call for a cycle each hour, but checks if room temperature has dropped significantly since the last call and only fires the boiler if it has dropped below the  calculated setpoint.

Mark N

Thermostat

Chris



From my own testing, I have an old T87, the newer digital T87, and the FocusPro. With the anticipator set to .8(as per the Burnham manual) on the old T87 and the cph set to 1 on the newer digital tstats I've observed the system to run very much the same. Normally on for 20 to 25 minutes and off for about the same amount of time depending on how cold it is outside. It is still quite mild out, wait for the colder weather when the boiler will start to run more often to see which setting work better. Don't forget that the placement of the tstat will greatly affect its operation.

ChrisJ

T8775

Does the Honeywell T8775 round digital use mathematical algorithms to figure out how long to run the system, or only better thermostats?



Mark N, I'll continue to watch how the system behaves. I currently have the anticipator around .9 just to see what happens.

Mike Kusiak_2

Digital algorithm

I believe any thermostat which has a CPH setting uses an algorithm to calculate the equivalent of an anticipator function.



The real "cheapie" thermostats don't have CPH settings, but a "swing" or differential setting instead. This just allows you to specify how many degrees between when the thermostat calls for heat and when it is satisfied.

Wendell

The figures are in...

measured with an outside temperature of 30 degrees and calm winds, my un-insulated Cape runs .8 hours more per day if it's allowed to cycle on the hour versus every two.



With the thermostat set to 70 degrees and the boiler cycling every hour (manipulated via the anticipator), the temperature shift is just over half a degree (which is very comfy). When the system is allowed to saturate the radiators and cycle every two hours, the temperature shift is 1-1/2 degrees (not as comfy, but the dog doesn't seem to mind).



Steaming on the hour takes 8 minutes to close the mains.

Steaming every two hours takes only 2 minutes more to close the mains.

For my system, the savings is found in keeping the total amount of pre-heats in a 24 hour time period to a minimum.



-Wendell

Dave in QCA

Interesting

I am not terribly surprised, there is cost related to comfort.  That is why we have central heating in the first place.....



But I have a question... did you count the total on time in your comparison, or were you assuming that the warm up times were wasted, and so just counted them as lost?



Remember, that in most cases, even though your basement is not conditioned space, the heat that is lost down there affects your first floor and much of that heat that goes into the warm up winds up in your living space too.

Wendell

The .8 difference was tallied, not assumed.

I kept copious notes using an old fashion egg timer. It kept me abreast of up and coming events (thermostat changes and the gentle rattle of a Hoffman 75 that was just about to close). Timing a system over a long period of time is not for the faint of heart.



The new steamer is yet to be insulated. I think I'll keep it that way. I'm now enjoying a nice warm woodworking shop.

Wendell

Setback

I usually set my thermostat back 3-4 degrees while I'm away at work. Last month I left the thermostat untouched as we've been experiencing a relatively warm winter. To my surprise I used less gas.



On any given month, I'm usually 30-35% less efficient than my neighbors. Last month for the first time ever I was down to 25%. Go figure.

Charlie from wmass

Hello Wendell.

I really think you would be well served to use the orfices. In vapour systems one of the benefits is that the radiators need not be heated to saturation. By limiting the steam to what you need for the heat loss of the room you will start using less fuel as the system does not produce more steam than is required for the building and it will be a more even heat cycle.

Wendell

Hi, Charlie!

Once again, thanks for a wonderful install. You're a true craftsmen.



I've tested the system both with and without the orifices. Unfortunately, they add 12 minutes to a cycle regardless of the cycles frequency. I think they are too restrictive.



Didn't the original Moline vapor/vacuum setup create a vacuum on the returns assisting in "pulling" steam into the radiators? I'm guessing the now missing pressure differential is causing the slow radiator heating.



The old oversized Burnham made enough pressure to make the orifices actually hiss. The radiators heated rather quickly (sometimes too quickly causing hammering in the returns). The new properly sized Weil McLain's pressure is so low that the radiators are completely quiet, but very slow to heat.



I was using 55% more gas than my neighbors with the orifices installed, 35% more with them removed, and now only 25% more by leaving the thermostat to its own devices. Not to bad considering there's no insulation here.



Removing the orifice sleeves has shortened the burner on time by 12 minutes.



Even with the sleeves removed the valves still function as intended when adjusting a radiators output. The steam flow is so gentle now that a full quarter turn is needed to make a difference. I have three of them choked down and two of them turned off. Adjusting each room is a cinch.



Please don't laugh, but one afternoon I removed my two return vents and replaced them with my battery powered DeWALT shop vac. I connected things up with clear vinyl tubing, barbed brass fittings, and of course, duct tape. I fired up the boiler and as soon as the mains closed I switched on the vacuum… man did those radiators fill with steam fast!



Perhaps in the future there'll be a vacuum cleaner hybrid



As it stands now, the house is very quiet, the radiators are easy to adjust, and our efficiency has never been better.



-Wendell



Edit: The silly vac test was just for fun... the system was not left that way.

Rod

Shop Vac

Hi Wendell-

   Actually with the shop vac experiment you may be on to something. I read a post recently where someone else trying boosting the venting with a shop vac set up and got very positive results.  If the faster distribution means shorter burner ON time with the direction fuel prices going, the shop vac may have potential. You now have me wondering what the difference would be using the vac with the orifices in place,

- Rod

Wendell

That's too funny...

I was looking to see how steam behaved under a vacuum, and wasn't actually intending to invent something. I think I'll leave my incredibly uncomplicated system alone for now... two pipes, no inlet or outlet restrictions and a gentle steamer.



-Wendell