How low can you go?

Steve_175

With the steam pressure?

I have got my system pretty well dialed in thanks to the help of the pro's here and the arm chair enthusiast's. I upped my main venting, lowered my rad venting (Gorton 4&5's), got a vaporstat & and low pressure gauge, skimmed several times (cold & hot) and fixed a small section of main that was level. All the rads heat pretty evenly and thoroughly. Also the water level has not dropped at all after several weeks of running.

See older thread.

<a href="http://www.heatinghelp.com/forum-thread/133504/Advanced-Venting-Q#p1211149">http://www.heatinghelp.com/forum-thread/133504/Advanced-Venting-Q#p1211149</a>



After I installed the low pressure gauge (0-20oz) I observed it never going above 2 oz. The boiler would keep running until the tstat was satisfied. Tonight I had a large set back (62f-66f) recovery, and at the very end of the heating cycle I saw the gauge climb to 6.5oz (first time I have seen that with the new system) At this point some of the Gortons were hissing a bit under the extra pressure. As soon as the system shut down everything quieted and within a minute the same rad vents that were complaining were now making a little noise as they were in a vacuum letting air back into the system.



I can't help but feel that a good chunk of the firing time could be reduced because of the flywheel effect with the rads full of steam. I was/am hopping the vaporstat will cycle the system off periodically to allow the heat in the rads to have a chance to dissipate without the system trying to force feed the rads more steam.



Your opinions?

nicholas bonham-carter

low pressure trophy!

go to the head of the class! your efforts at making your system function properly will reward you with greater comfort and economy.

i don't think there is a need to increase the number of cycles, or the anticipation on the thermostat, because the radiators will only heat up to steam temperature, and they are storing that heat to be radiated slowly into the room. when they have given off as much heat as they held, and the room temperature drops a degree, then back on goes the boiler to repeat the process of heating the rads. if the source of heat was 300 lbs. of iron heated by torch, then you would have to pay attention to cutting off the flame before the iron became red-hot.--nbc

Steve_175

Spelling

Be sure you get my name right when you send me that trophy. ;-)



I realize my system is doing really well. I am just trying to chase down that last 2% of possible efficiency improvement, if at all possible.



Before the gauge started to climb to 6.5oz the rads were all ready to hot to touch. It seems like the last stretch of that heat cylce was a bit of a waste because the house was getting to the set point even if the boiler had been shut off.

Irv

One pipe steam

Which vaporstat would you use? Some people use the one with ounces, other recommend the one in pounds.

Steve_175

Vaporstat

This is the one that was recommended to me by others here and the one you sse in the pic. It is in ounces.

http://www.patriot-supply.com/products/showitem.cfm/HONEYWELL_L408J1009



I laso got this low pressure gauge.

http://www.gaugestore.com/prodinfo.asp?number=33015



And a snubber to go below all that stuff to even out fluctuations.

http://www.valvestore.com/prodinfo.asp?number=32618

Steve_175

Great Idea

Thanks Mark. Glad to know I am not the only one who was trying to figure this out. Unfortunately I am only able to wire in a new light switch, even with your instructions its a bit above my pay grade.

How much would you charge to make one up for me?

Irv

Seems

You hooked it up with the r b connections and not the w.

Would this way make it work on pressure rise ?

Irv

W

haaljo

'Time delay relay is good idea

especially if you are overfired. Steam pro's have told me about "black boxes" that have been sold to property owners that are just a $20 timer in a $600 box.

There have been threads in the past on intelligent controls that delay start based on condensate temperature and/or outside air. I remember Steamhead installing some type of control in a big apartment complex and he wrote a paper on it. I think it's the Calvert Job here:

http://72.3.142.104/professional/79/All-Steamed-Up-Inc

Steve_175

Wiring

Wiring and electrical are not my area of expertise. If you are asking why I did it this way, it is how I thought it was supposed to be done. Anybody want to chime in and tell me I did it wrong and why, I am all ears.

Irv

Didn't

intend to ruffle your feathers by asking you the wiring question.

Just exploring all the wiring options for this unit.

crash2009

Lookin Good Steve!

I have some questions to help me better understand how a vaporstat works.  I plan to be installing one in the next few days.



What pressure does it shut off at?

What pressure does it turn back on?

On the vaporstat, what settings are you using?  (main and diff)

Do these settings match the gauge?

Steve_175

What indeed

Wish I new the answer to some of those Q's

It does not seem to shut off at pressure because the pressure never gets that high. The highest I have seen the gauge go was 6.5oz. One fear I have is what is discussed in this thread.

http://www.heatinghelp.com/forum-thread/128249/why-do-Honeywell-vaporstats-suck-so-badly

BobC

vaporstat accuracy

After my second pressuretrol started to get a bit flaky, I bought a NOS mercury bulb (SPDT) vaporstat, the 0-4 lb -L608.



I've been in engineering for 40+ years and I know that a mercury bulb will outlast any microswitch. As long as the mechanical linkage is good they will perform consistently for a very long time.



I've been using that for about a year and a half now and I've noticed a few things. The scale reading and the operation point are not the same but they repeat very well. I have the cutout so it trips at 12 oz (setting is 1lb) and the cut in is 4oz (setting is 8oz). So it seems the cutout is off but the cut in is pretty accurate. I'm using a 0-3PSI gauge for the measurements.



This model vaporstat seems to have a bit of chatter at the 12-16oz area but the mechanical hysteresis prevents contact bounce.



For me the bottom line is I really don't care how accurate it is as long as it repeats accurately, which it does. Also you can bias the operating point by mounting the unit slightly off the vertical. My setup is level when hot but slightly off when cool; thats probably due to the brass pigtail  twisting as it heats up.



i measured the temperature of the T that the vaporstat and the gauge mount off of and it's 125 degrees when the boiler is coming back from it's 4 degree night setback. The base of the vaporstat and gauge is less.



Bob

crash2009

Settings

In the picture at the top of your post, it appears you are set to main 4oz and diff 9oz. 

Is that where you are set?

crash2009

Is yours subtractive Bob?

Are you set at 16oz on the main and 4oz on the diff?  Is that how you get shut off at 12oz? 

BobC

Subtractive.

It is the L608a-1053 which is subtractive.



Your inquiry made me go down and check the actual setting (I was relying on memory - not always the best idea). The Main is set at 1 LB and the Diff is set at 12 oz so my original statement was correct in that the cutout was 4oz off but the cut in was where it should be (16-12=4oz).



I might be able to diddle internally to get the settings and actual to agree but I'm content to let sleeping dogs lie.



The pics show the general setup as well as the specific settings. Sorry about the flashback but I wanted the whole face of the vaporstat to be in focus.



Bob

crash2009

Sorry to get you out of your easy chair Bob

 It was time to check the water level anyway. 

Your vaporstat has no ounce setting for the main.  For Steve and I, to duplicate your settings we would have to set the main to 16oz, and the diff to 12oz.  (16-12=4) 4oz would start? or stop? the burner. 

How do we know when it would shut off?

BobC

Instructions

I visit the boiler on a daily basis just to make sure Mr Murphy is not up to his usual tricks; also I keep a log to track fuel consumption and any water I add to the boiler. I don't trust auto water feeders - in manual valves I trust.



I scanned the Settings page of the instructions that came with the vaporstat and they pretty much explain everythijng. The main setting determines the cutout point while the cutin is determined by the Main minus the Diff setting.



My particular vaporstat is not calibrated very well but it does repeat very well. From other posts I've seen the calibration is not very good on these so a low pressure gauge is essential to set them up correctly.



Bob

Mike Kusiak_2

Settings

Crash, you can't necessarily go by Bob's settings. The calibration of your vaporstat may be much different than Bob's. The best way to insure correct settings is to actually measure the cut-in and cut-out pressures on a low pressure gauge and adjust accordingly. Don't go by the actual scale markings as they are typically way off in a random fashion.

crash2009

I wouldn't write it off that quick Steve

  If you are set like the photo at the top of this page, and I am understanding what has been said here.  Main 4 and Diff 9, Your vaporstat will allow the burner to come on at -5oz, and will shut off the burner at +9oz.

Bob is set for on at 4oz and off at 16oz.

I understand that the indicator on the vaporstat will not nescesarily be exactly the same as the gauge.  (I guess this is where the flakey comes in, but the backplate of the indicator appears to be adjustable) Bob says his reliably on's and off's the boiler at the same place every time.  That's all we really want anyway. 

Thanks for helping me understand how the on's and off's are calculated.