A STEAM RIDDLE FOR PROS WHO CAN SOLVE?

jim_72

Bob I know for certain that I am cycling on pressure. My gauge at the pressuretrol has a 1oz to 48oz range and reaches exactly 24oz at cut out during the short cycling.We both use Honeywell programmable stats set to steam as well as independent hot water water heaters.I am confused how my neighbor's system, lacking main vents and nearly as oversized as mine,can archive such smooth performance right out of the box . Thanks JIm

jim_72

A STEAM RIDDLE FOR PROS WHO CAN SOLVE?

Guys just a little background. I have learned much here on maintaining and improving my one pipe gas steam system over the years.I have a semi detached one family home heated with a peerless boiler . The system preforms well even during prolonged cold spells when we would have continuous design days where it would run approx 20mins per hour maintaining a steady 68 degrees for 24 hours. The only short coming the system has is the boiler is 100% oversized via the connected load. I have known this for years and have tried everything short of downfiring to stop the constant short cycling that occurs after the rads completely fill and then the system cuts in and out on pressure until the stat is satisfied.I only lack and seek that steam heat "Nirvana" of one long burn to temp sans the cycles.And here begins the riddle.
My attached neighbor who owes the exact house as mine has just replaced his boiler. Our houses were built with identical plumbing specs and both contain the original twin mains, again same in length and 2". Over the years the the rads have been replaced in both homes with identical CI baseray baseboards and both homes have 210 sqft edr.
His installers did a professional install- Ward fittings/ all threaded black pipe(no copper)/proper header and near boiler pipeing.We started his system today from a 2 degree setback and it purred to temp "never stopping "with a rock solid water line. His speed to steam were identical to my system- 6 mins to header- another 4mins to the ends of both mains and all rads full in 22mins. What amazed me was he was able to achieve the same performance as my system WITHOUT THE SHORT CYCLES.I emphasize this because although both my mains are properly vented with Gordon #2 vents his mains have NO VENTS at all! Not only that but the new boiler that he had installed is 85% OVERSIZED! How can he achieve a a long beautiful, cycle free, burn with no main vents and a boiler that is 15% smaller then mine.Below I show the specs for his system compared to mine . Both systems use fully opened and functioning Vari-vents on the rads and none of the mains that are the same in both homes have any insulation because they are used to heat the finished basements.

My house

Boiler -Peerless G561
Input- 160000
DOE MBH-129000
Net IBR steam- 404 sqft
Twin 2"supplies into 3" drop header with two takeoffs all piping is properly pitched and quiet.

Rads- 210sqft EDR of cast iron baseboard with fully opened vari-vents

Pressuretrol setting - .5 cut in/ 1lb cut out

Two Mains- One 35' x 2" with Gordon #2 vent no insulation
One 25' x 2" with Gordon #2 vent no insulation.

Neighbor's New Boiler

New Yorker CGS50A
Input 140000
DOE 115000
Net IBR Steam- 358sqft
One 2" supply to proper 2" header with two takeoffs all piing is properly pitched and quiet.

Rads- Same as mine

Pressuretrol setting -Same as mine

Two Mains same as mine in size no insulation but they have NO VENTS.


Sorry for the length of all this Guys but is it possible that if my boiler was just 15% smaller yet still 85% oversized I could eliminate my short cycling problem?Could I achive this by having a Pro derate it 15% or is there something wrong with this picture. Thanks and I appreciate any response. Jim

bob_46

Cycle

Jim, are you sure that you are cycling on the pressure switch? Do you and your neighbor have identical thermostats with the heat anticipators set the same?

kpc_42

sounds like....

the varivents are doing all the work.
Some systems do this fine if the vents are working well. The only problem is the vents life could be shortened.

Steamhead (in transit)

Has the New Boiler

been cleaned? What is the condition of the water in yours?

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

jim_72

Gordo the new boiler has been properly skimmed and as stated maintains a rock steady water line when steaming. I personally clean my system every year .Clean burners/flue/pigtail etc. I add quart of Rhomar when the season starts and remove all sediment as it loosens . At present my water is clean and during steaming I have a gentle 1/2" bounce in the gauge glass just like every other years. Thanks Jim

[Deleted User]

Clock the

gas meter(s) to determine actual input of each appliance.

The Steam Whisperer (Formerly Boilerpro)

Yes, I d check that first

Udnersized gas lines seem to be the norm, especially with oversized boilers

jim_72

Guys I clocked my meter based on a content of 1027btu per cuft in the Queens area and came up with with an input of 154000 btu's. I have not been able to to access my neighbor's meter but based on my input am I slightly derated at the meter. My pressure regulator has a size 45 orifice set for 1050 btus per cuft at 3.5 water column. Thanks Jim

chuckNJ

think differently...

Hi, fellow home -onepipesteam- owner here also (an Wall fan)....I'd like to suggest that you should be thinking about those uninsulated mains as part of radiation, not something handled by pickup factor. I don't have the necessary dimensional info handy, but if you calculate the surface area of those mains and add that to your edr I think you will find your neighbor's boiler much closer to the load than yours, and viewed in light of that larger proportional difference (his is close to load, yours is oversize), the performance difference observed will be more understandable. In which case, professional downfiring could help.

Or maybe I'm way off here...

jim_72

Chuck that is understood since we both have identical sized mains. Considering that there is only a 20M imput difference between the two systems I am hoping to hear from the Guys based on all the info given if a safe minimal derate could possibly eliminate my systems incessant short cycling. Thanks Jim