Joined on November 14, 2009
Last Post on March 10, 2014
@ November 20, 2012 3:37 PM in A Steam Enthusiast's Outdoor Reset ControlI live in an 1890’s three-story brick home in south-eastern Pennsylvania with a one-pipe steam heating system. The boiler was replaced in 2009, and after fine-tuning and balancing the rest of the heating system (insulating the mains, re-sizing and replacing vents on the steam mains and radiators using the Gill & Pajek vent capacity charts), I began looking at other ways to reduce fuel consumption. An outdoor reset control was at the top of the list. The commercially available outdoor reset controls all lacked specific features I wanted, so with a background in industrial process control I decided to develop my own control, which I’ve dubbed "BMC" for Boiler Monitoring & Control.
This has been a work-in-progress since 2010. The first iteration was a time delay relay to control end-of-cycle short cycling on pressure. This was followed by a clock timer/relay control to schedule production of domestic hot water. For the third iteration, I purchased sensors and wrote some software to do data acquisition and charting of temperatures and pressure at the tail end of the 2010 heating season. The current iteration incorporates the mechanical controls into the software and adds outdoor reset modeling. I've had the software in control of the boiler since January 2012, with some fine-tuning along the way.
Before I get started, I'd like to take this opportunity to thank Dan Holohan and all the contributors here at HeatingHelp.com for sharing their knowledge and expertise over the years. Thanks guys!
@ September 20, 2012 11:32 AM in Midco Radial BurnerI've already prepaid my oil for this year (ouch!), but come spring I'll be taking a closer look at this unit.
I wonder if this burner could be modulated using steam pressure. Seems to me that given an otherwise well-tuned steam system, the objective would be to first fill the mains on high fire, then turn down to maintain an optimal system pressure. You'd need some way to de-bounce the pressure signal, especially if the operating pressure is very low. I have a 4-20ma, 0-3 PSI pressure transmitter on the gauge pigtail (which I'm currently using with my home-grown outdoor reset control) that would be perfect for this application.
@ August 19, 2012 7:26 AM in Utica Starfire 3 steam boiler- oil burner conversion to gas burnerBill, how do you distinguish a first-generation Starfire, and how is it better than a later model? Mine was installed in 2009 and, like Helm, I'm thinking about a gas power burner conversion.
@ May 19, 2012 5:47 PM in Is this why we make fun of engineerswas when the author wrote, "Steam heat is wasteful". Steam heat is wonderful, poor maintenance is wasteful.
@ March 31, 2012 6:31 PM in Tankless coil into water heater tank?My friend doesn't have gas, so Icesailor's side-arm solution just might work for him.
Icesailor, do you have any data on fuel savings in the off-season between a regular tankless coil and your system?
@ March 31, 2012 5:58 PM in energy usage this winter .. (it is over now right??)is a PC-based application program that I've been working on since 2010. It runs on an repurposed laptop that's been dedicated to home automation - it runs the boiler and lighting controls for the house. Sensors are connected to the PC using Phidgets USB-based I/O (www.phidgets.com).
I put in a couple of features that are lacking in the commercial systems. The outdoor reset model uses the heat loss of the building and the net firing rate of the boiler in addition to the outdoor temperature to calculate how long the burner should run. It also has the option to fetch wind chill temperature over the Internet from a local weather station and use that as the outdoor temperature.
I'm working on a more detailed writeup to post in the near future. Stay tuned.
@ March 29, 2012 10:26 PM in Tankless coil into water heater tank?In this configuration, if it were me I think I'd disconnect the aquastat on the boiler altogether.
@ March 29, 2012 10:20 PM in energy usage this winter .. (it is over now right??)This year: 12/1/11 to 3/6/12
Consumption: 635 gals
Last year: 12/15/10 to 4/6/11
Consumption: 991 gals
I put an outdoor reset + heat loss mathematical model of my own design in control of the boiler in January, and while the early results are promising - 0.226 vs 0.187 Gal/HDD is a 17% reduction in fuel usage - whether it holds up under a "normal" winter remains to be seen.
@ March 29, 2012 4:31 PM in Tankless coil into water heater tank?I'm posting on behalf of a friend who has an oil-fired steam boiler with a tankless coil for DHW, and he's wondering if it would be practical to pipe the outlet of the tankless coil into an electric or gas fired water heater tank. His thinking is that in the summer he could shut down the boiler and let the water heater do all the work, while in the winter with the boiler running the tankless coil would preheat the water going into the water heater.
Seems simple enough, so there must be a catch somewhere. What are the pros and cons of such a setup?
@ March 8, 2012 11:12 PM in Repipe for water hammerfor the feedback, Jamie. Yeah, it is amazing the difference an inch or two can make. The drawing isn't quite to scale, where the sloping return ties in is only 15" or so above the floor so it's definitely wet. I used a mechanic's stethoscope to listen for the hammer (more of a tapping, actually) along that sloping return, and it was most pronounced around the tee at the water line.
I figure when the Dead Men piped this back in 1890, the water line on the original coal-fired boiler was a lot higher than it is today. It's probably just coincidence that the current boiler's water line just happens to be at that tee. I wonder if that whole sloping return used to be wet, since the initial vertical drop on the south wall is more than the 28" 'A' dimension.
@ March 8, 2012 6:36 PM in Repipe for water hammerI have a water hammer problem that I'm pretty sure I know how to fix, but would like to get a second opinion from the folks here. Here's the situation (sketch attached):
The return line off of the main on the south wall of the house initially drops 34" from the main, then traverses the full length of the west wall with about a 1/2" per foot slope, then again about 10 feet on the north wall before it ties into a vertical return pipe midway down the main on the north wall and returns to the boiler.
The return line off of the end of the north wall main ties into the sloping return pipe on the east wall about 32" from the floor, which coincidentally happens to be where the water line is on the new boiler. I'm getting water hammer in this line midway thru the cycle, and I'm guessing that the water line isn't high enough at that point to flood the tee, so there are two steam paths into a what's become a partially dry return. If I raise the water level in the boiler an inch or two the problem subsides.
My plan is to repipe the return on the north wall main so that it drops to floor level before tying into the wet return. Am I on the right track here, or should I do something else?
@ February 19, 2012 8:51 PM in Single Steam Pipe Venting - Sizingspend ten bucks at the shop here and get a copy of this:
Balancing Steam Systems Using A Vent Capacity Chart
@ February 19, 2012 10:46 AM in Cycleguard on Smith boiler preventing radiators from heatingSorry about that, I mixed up the product names. Should have read replaced CycleGuard with SafeGuard, for the same reasons you're replacing yours. I found that every time it cut off the burner for 90 seconds it took a couple of minutes to rebuild the head of steam.
@ February 18, 2012 11:08 AM in Cycleguard on Smith boiler preventing radiators from heatingcan be used with the Cycleguard. I replaced my SafeGuard with a CycleGuard more than two years ago. Removed the SafeGuard probe to compare with the CycleGuard , found the probes were identical, so I put the SafeGuard probe back in and put the new CycleGuard probe away as a spare. Works fine.
@ October 21, 2011 7:29 AM in Radiator enclosuresAfter reading the Radiator Enclosures article in the Library here, I'm interested in constructing a few enclosures for our 1-pipe steam radiators to increase their efficiency. In the first example,marked "Deduct 10%", the article is unclear on a couple of points and I'm hoping someone here can answer a few questions:
1. What is the "B" dimension for a 36-39" tall radiator?
2. How far above the top of the radiator should the board extend?
3. Is the board supposed to enclose the radiator on the sides as well as across the front?
4. Will it help, hurt, or make no difference if I put reflective foil behind the radiator?
If someone has built covers in this style, I'd love to see some photos.
@ April 21, 2011 1:42 PM in Firing rate - ratings versus actualI have a Utica oil-fired steamer with a 1.50 GPH @ 140 PSI nozzle. The service tech confirmed the actual nozzle size and operating pressure. I have an hour meter installed on the boiler, and track usage when the tank is filled. In 9 fills over the last two seasons, the calculated actual flow rate has been between 1.67 and 1.96 GPH, with the majority in the 1.75 GPH range.
Are these normal deviations? I don't expect it to hit 1.50 all the time, but if it's consistently 0.25 higher than that, does that indicate a problem or something to be checked?
@ March 5, 2011 9:49 AM in Suspension boilerA friend is having a new basement slab poured. Here's a pic of how they got the boiler and hot water heaters out of the way.
@ February 11, 2011 6:49 AM in How low can you go?On the L408J1009 vaporstat, R-B are normally-closed switch contacts, R-W are normally-open. So on pressure rise, the switch action will break R-B and make R-W. R-B are the contacts used in a typical line voltage installation where the vaporstat interrupts the burner power circuit.
@ February 10, 2011 6:49 AM in How low can you go?Hi Steve,
Like you, I have my system running at very low pressure, 1 to 1.5 ounces, and the pressure doesn't start to increase until near the end of a recovery from setback. I'm also of the opinion that continuing to fire once the pressure gets above a certain point is just wasted fuel. In my case, I have the vaporstat set to cut out at 3.5 ounces and cut-in at a slight negative pressure, around -0.5 oz.
The trouble I ran into was that when the vaporstat trips on pressure, it cuts back in after only 30 seconds or so. So I added a time delay relay that keeps the burner off for 20 minutes after the vaporstat cuts out. This lets the latent heat do its thing. It's been in place since last March and so far there has yet to be a cycle where the flywheel effect failed to "coast" to the thermostat setpoint. The average time for my system to go from "cut-out" to "setpoint reached" averages around 10 minutes.
I posted a couple of wiring diagrams, one for 24V and one for line voltage in this thread:http://www.heatinghelp.com/forum-thread/129949/Temperature-based-cut-in-for-a-Vaporstat#p1190138
Both versions are designed to consume no power until the vaporstat cuts out, and the vaporstat is wired to the make-on-cutout side (R-W) of the switch rather than the break-on-cutout (R-B) side. I implemented the 24V version, because I didn't want to mess around with line voltage if I didn't have to, and also because I was able to get the 24V supply voltage from the burner control.
@ January 20, 2011 8:14 AM in Advice on vaporstat?Alternatives:
I'm not aware of any other low pressure mechanical controls out there that do what a vaporstat does (not at that price point at least). Depending on how badly you've caught the "steam enthusiast" bug, you could go off the deep end and venture into the electrical control arena.
I've installed a 0-3 PSI, 4-20ma pressure transmitter on a pigtail, wired to (relatively) inexpensive I/O (www.phidgets.com), which in turn is connected to a PC that is running software I wrote to record the pressure, indoor and outdoor temps, far rad temp, tankless coil outlet and tempered temps on a continuous basis. Next season I am looking at writing some more code and adding I/O to use the pressure transmitter as an operating control, replacing the vaporstat and the mechanical relay that's in place now.
The WIKA 0-3 PSI gauge from GaugeStore.com is fine for steam, since the gauge is installed on a pigtail that isolates the steam from the gauge.
0-4 lb vs 0-15 oz Vaporstat
The potential downside to a 0-4 lb vaporstat is that, like most controls, they tend to be more accurate in the middle of their range and less so at their low and high extremes. So if you install a 0-4 lb vstat and it turns out that your cutout pressure is, say, 8 oz, you're in the lower 12-1/2% of the operating range. On a 0-16 oz vstat, you're right in the 50% range.
I'd recommend that you first install the 0-3 PSI gauge and get an idea of what your operating pressures are, and use that data to decide which vaporstat to install.
@ January 20, 2011 6:11 AM in Advice on vaporstat?Hi David, that's my setup with the pressuretrol and vaporstat. The pressuretrol is the safety control and is wired into a 120VAC circuit, as orginally equipped by the manufacturer. The vaporstat is an an operating limit switch, wired in the NC position (break on hi pressure) set to cut out at 3.5 oz, and is in a low voltage 24 circuit along with a time delay relay.
My system runs at very low pressure, between 1 and 2 oz, and if it gets to the cut-out point on the vaporstat, I know that the system is completely filled with steam, so rather than short-cycle, the time delay relay kicks in and holds the thermostat circuit open for 20 minutes. The latent heat in the radiators continues to heat the building, and if the thermostat still isn't satisfied after 20 mins, the system will turn on again (though I've yet to have that happen).
I think the point of the "Why Do Honeywell Vaporstats Suck" thread isn't that they don't work, it's that they don't come calibrated out-of-the-box. For pros like Gerry Gill, this has got to be a huge pain to have to take time to set up each vaporstat, but as a homeowner I only had to do itonce, so no big deal. In that thread, Gerry describes a calibration jig he uses, and near the end of the thread is one I cooked up with a low pressure gauge and some 1/4" fittings.
@ December 21, 2010 9:28 PM in Which LWCO? CG400 1060 or 2090I check my boiler water level and quality regularly, and don't have any problems with foaming, so for me it came down to an issue of fuel (oil) economy. On a 45 minute heat cycle, the LWCO would shut the boiler down twice to do the foam check. Each time it did, the system took three minutes to heat back up to where it was before the shutdown. That's an extra six minutes of fuel burned recovering from the foam test in a single heat cycle. If that happens four times a day during the heavy heating season (say 12 weeks), that's 24 minutes * 12 weeks * 7 days = 2016 mins or 33.6 hours or roughly a week's worth of extra fuel used per season. That's why I opted to swap out the CycleGard for a SafeGard.
So back to your system. Let me say first that I'm not a pro, just a homeowner/enthusiast. From what you've described, my first concern is if your LWCO is working properly. Has the LWCO probe been cleaned/inspected recently, and has the LWCO been tested to ensure that it does in fact cut out on low water?
Is your normal water line at the recommended height when the boiler is not firing? According to the installation manual for your boiler, the water line should be 23-13/16 inches from the bottom of the boiler section leg, where it rests on the boiler room floor or boiler foundation.
Page 16 of the manual talks about installing an optional "reservoir pipe" if the time it takes the condensate to return to the boiler is longer than 10 minutes. This may or may not apply to your situation, but if it does it might explain why your water level drops (although it doesn't explain why the LWCO doesn't cut off).
When the boiler fires up how long does it take for the water to drop out of the sight glass? When it shuts down, how long does it take the water level return to normal?
Please post some pictures of your boiler so we can see what you're dealing with, including the LWCO, the sight glass, the near-boiler piping and the risers to the mains for starters.