Built in 1909-1910, the Louis P. Best residence is a very large example of the Spanish Mission style of architecture, with 8400 gross sq. ft. of floor space. In addition to the main residence, there is an adjacent 2 story, 3-car garage with chauffer’s apartment above, which adds another 2100 sq ft. The structures of the buildings were considered “fireproof” at the time, with all walls and floors being masonry and reinforced concrete. There are numerous examples of complex engineering in the construction of the house. Perhaps an equal feat, was the moving of a very large Victorian house from the site to a vacant lot down the street, to make way for the construction of L P Best’s new home. The residence was converted to apartments in 1928.
The heart of the heating system appears to have been a firebox/fire tube steam boiler. The very long and narrow foot print of the boiler in the concrete floor seems to indicate this. Local building permits indicate that a gas conversion burner was installed in 1954. In 1967, the boiler was replaced with a Weil-McLain low pressure steam boiler. I’m not sure what happened, but this boiler had a very short life. In 1975, the boiler was replaced with a Pennco Model 40M 1050S, which is a 1,050,000 BTU/HR cast iron sectional boiler, very similar to the Pennco 41J series currently in production. See manufactures information at <a href="http://penncoboilers.com/product_detail.asp?key=168">[u][size=12][color=#800080]http://penncoboilers.com/product_detail.asp?key=168[/color][/size][/u]</a> . After 35 years of service, the current Pennco boiler seems to be in very good operating condition.
Original total radiation was 1865 sq ft. Radiators appear to be Sun Radiators. They are unmarked except for a small “S” in the casting. They are undecorated versions of those shown in the Sun Boilers and Radiators Catalog; available on this website at, <a href="http://www.heatinghelp.com/files/articles/1064/210.pdf">[u][size=12][color=#800080]http://www.heatinghelp.com/files/articles/1064/210.pdf[/color][/size][/u]</a> . My assumption is that this undated catalog is from an earlier period, and that the radiators were simplified and modernized by 1909. The overall shapes of the castings are identical.
All radiators were fitted with ½” Dunham #2 Traps, seven of which remain. Steam inlet valves are at the bottom of the radiator and are piped large. Radiators 80 EDR and above are 1 ½”; 30-79 EDR, 1 ¼”; and less than 30 EDR, 1”. In the boiler room, there is evidence of a return trap, with a ¾’ steam pipe feed that has been capped in mid air. There is also evidence of other floor mounted equipment adjacent to the original boiler location. There is original electrical service, in conduit, to the boiler room. These cloth and rubber insulated wires are both red in color, with no neutral, and pass through a more modern DPST fused disconnect switch. This would seem to indicate that there was something running on 220v in the beginning, and I assume it was a vacuum pump. This electrical service has since been changed to 120v, with one leg of the old wires being cut off of the terminal screws in the disconnect switch and remounted to the neutral bar. Of course, it was also reconnected to the neutral at the main panel. This service now powers the boiler controls.
When the building was purchased in June 2008, about half of the radiators had air vents installed. This is a sure sign of traps having failed in the closed position. In addition, there had been F&T traps added to the condensate return lines at the point they drop into the vented condensate receiver tank. This is obviously someone’s “fix” for radiator traps that had failed in the open position. Some of the original radiation had been removed from service. These were as follows, all radiators in the garage, 2 large indirect radiators that provided fresh air, a kitchen radiator, and a couple of small ones in the original side hall. Two new radiators were added at the end of very long laterals when the front corner screened porch was enclosed to make additional living space. Additionally, there had been a few replacements where small tube radiators with a much smaller EDR than the original had been installed. In the front stair hall, the foot prints of the original radiator and the height of the original heat shield indicate that the original radiator was a 3-column by 22-section, with a resulting EDR of 110. It had been replaced with a small tube midget with an EDR of 42. All of this resulted in a total connected EDR = 1285 sq ft, less than half the 2600 sq ft rating of the boiler! The boiler was controlled by a Honeywell round thermostat located in the 2nd floor hallway, at the top of the open staircase. This only source of heat in this space was the grossly undersized foyer radiator. Even with the thermostat set at 68, most of the space was over heated. Heat was uneven and the boiler short cycled. Annual gas bills topped $8700.
My previous experience with steam consisted of operating a large system in a school building and an even larger high pressure steam system in a hospital complex. While I had considerable experience with cast iron hot water systems in historic properties, I did not have experience with low/no pressure steam residential systems. I had a lot to learn, but luckily I found the Heating Help website. It has been a fantastic resource!
Immediately after the purchase of the building in June, 2008, I put together a plan of attack. Prior to the beginning of the heating season, the following items would be completed:
· Remove all air vents from radiators.
· Repair and/or replace all defective radiator traps.
· Remove the 2 F&T traps from the condensate return mains.
· Lower the firing rate of the boiler.
· Install a control system that would regulate firing time.
I began the project by removing all of the air vents from the radiators. A simple task! Repairing radiator steam traps was deferred until the heating system was brought into operation in the fall, so that the operation of the trap could be observed. The second summertime work item was the installation of a Tekmar 279 controller. I included 2 indoor sensors; one in a north facing apartment and another in a south facing apartment. They are set up so that the colder of the two sensors has priority. An interesting issue with the Tekmar control is what I believe is an error in the installation instructions. For one pipe steam, it shows installing the condensate sensor on the riser to the very last radiator. This is to sense when steam has been established. Their instructions for a two pipe system indicate that the sensor should be installed on the condensate line coming out of the last radiator in the system. This location would cause the system to not sense a steam established condition until all of the radiation was completely heated. This would produce wild swings in temperature; at least it would in this building. I installed the sensor on the steam main, just after the last riser, in a location where the steam main essentially becomes a dry return and heads back to the boiler room. Operation of the Tekmar system has been good.
The next task was the repair and replacement of the steam traps. I bought a few traps online and started to replace a few of the Dunham #2 traps that were failed closed. I failed to realize the significance of flow restrictions by different trap manufacturers. The Dunham traps had a very large venting capacity, almost like blowing through an open pipe. When I replaced these with a new style Hoffman 17c, it did not work so well. Also, I replaced a Dunham side outlet trap with a bottom outlet trap, and in the process created a nice little water seal. As a result, I purchased Barnes and Jones cage units and caps to repair the old Dunham #2 traps that remained in the system. These have been very satisfactory. Other traps have been replaced or repaired. All existing Dunham Bush 1E traps have been repaired by installing new thermostatic discs. In a few locations, Armstrong TS-2 traps have been used as replacements for failed traps, but they too have a very unrestricted passage and seem to perform the same as the Dunham traps.
When all of the traps were repaired I removed the F&T traps from the returns. These were causing a significant restriction in the venting of the radiators. I noticed that the time that it takes for the mains to vent suddenly got much longer. Some of the radiators heat very quickly, while others seemed to have slowed down. A few of the rooms in the house were not getting enough heat, and with great reluctance, I reinstalled air vents so that those radiators would get steam quicker, and heat more sections in each firing cycle. It has taken me most of a year to conclude that one Hoffman #75 Main Vent, and one Dole #5 Quick Vent, do not provide sufficient venting for the system to operate properly.
Two grossly undersized radiators were replaced. In the foyer, two salvaged radiators were disassembled and reassembled to create a 22 section, 110 EDR radiator. The radiators used are United States Radiator, 38”x 5 tube, large tube style. In another room, a similar process was followed, constructing a 19 inch tall window radiator. Again, it is a United States Radiator, large tube design, 18 sections @ 4.25 sq ft / sec. for a total EDR of 76.5. Again, I had faint foot marks in the floor from the original radiator and limitation in height created by the presence of the window sill to help me to know the actual size of the original radiator.
It seems that someone had already lowered the firing rate by adjusting the regulator. The boiler was firing at 800,000 BTU, but I was able to lower it to about 725,000 BTU. Any additional reduction will require a change to the orifices, or the installation of a 2 stage gas control valve. I have not checked the manifold pressure, and that will be done this fall to help guide further firing rate reduction efforts.
The current work involves calculating the volume of the steam mains and increasing the venting capacity. An inherent design error appears to be the connection of the dry returns on 2 of the 3 loops on the system. However, it appears that this may have been compensated for by the installation of a vent in a distant area of the front loop. At an unknown time in the past, the vent was removed. I will reinstall vents in this location, as well as additional vents in the other two locations and see how the system works. (See attached file)
At present time, I am placing an order for additional helpful materials from Heating Help. They are as follows; Balancing Steam Systems using a Vent Capacity Chart, EDR – Ratings for Every Darn Radiator, Lost Art of Steam Heating, We Got Steam Heat, and Greening Steam. I can’t wait for them to arrive!
Attached images are Best Residence 2008, Best Residence 1923, Struck Residence being moved from Site, Louis P Best, sketch of basement steam mains.
Dave in Quad Cities, America
Weil-McLain 680 with Riello 2-stage burner, December 2012. Firing rate=375MBH Low, 690MBH Hi.
System = Early Dunham 2-pipe Vacuo-Vapor (inlet and outlet both at bottom of radiators) Traps are Dunham #2 rebuilt w. Barnes-Jones Cage Units, Dunham-Bush 1E, Mepco 1E, and Armstrong TS-2. All valves haveTunstall orifices sized at 8 oz.
Current connected load EDR= 1,259 sq ft, Original system EDR = 2,100 sq ft Vaporstat, 13 oz cutout, 4 oz cutin - Temp. control Tekmar 279.http://grandviewdavenport.com