Decisions, decisions... Multi-Family Steam System Upgrades

josepha

Currently manage a 20 unit building in NYC with steam heating issues. Few questions as I embark on converting to duel fuel (apologies in advance as I'm sure one or more of these have been answered; going to continue to search and dig)

Current Setup
- 20-units, 4 floors, (5 per floor) ~90 years old
- BOILER: BEST- SCOTCH MARINE 4A - 40
- BURNER: (not sure - carlin i think)
- CONTROLS: Older Fuel Watchman (disconnected/failed), bypassed to honeywell thermostat
- OIL TANK: 2,500 gal #2

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Tekmar 279 or Heattimer MPC?

Am looking to replace the controls and have looked at both the tekmar 279 and heat-timer platinum. Would like to go with the cheaper tekmar (also heard good things about it ), but like the fact that can network the MPC down the road and also heard (though not sure if true), that the tekmar 279 doesn't have the same learning capabilities as its brethren

Carlin or Powerflame?

Is there a big difference in performance, quality, price?

Separate water tank for summer?

Does it really save that much to switch to a gas fired tank for the summer (instead of firing the boiler?
Have heard that it may not be good to keep the boiler off

Sequence of events for optimal operation/balancing?

Right now is a mess, top floors get little heat, bottom floors over heated. Bypassed old fuel watchman that wasn't working to a off-the-shelf honeywell. As a result heat is erratic (cant find right temperature - too hot or too cold), boiler room drafty as basement windows cracked, pipes not completely insulated, and so on.

my question is: What should do first, second, etc...?
- controls
- venting
- insulation
- inspecting
- replace windows
- inspecting/replacing repairing unit radiators
- conversion to duel fuel - new burner
- anything else?



Thanks in advance for any help!

nicholas bonham-carter

Is this one pipe, or two pipe? Send us some pictures of the boiler, and it's piping.
1. The most important thing would be venting. If it is a one pipe system, With a building of this size, steam traps can be used instead of dozens of Gorton 2's on antlers.
2. Verify the pressure as being under 1 psi, with a 0-3 psi gauge. This gauge will tell you how good the venting is.
3. Before any pipe insulation is done, check the slope of all the horizontal pipes, marking the direction of flow, from the pitch, with pieces of tape marked with an arrow.
4. Check that thermostat for steam settings of 1 CPH. The honeywell visionpro does this, and can monitor temperature with a remote sensor, away from prying fingers! An Ecobee thermostat also has wireless remote sensors, and can average them more easily, and be Internet controlled, however the distance between it and the sensors can only be 45 ft. Do not use temperature setbacks of less than 24 hours duration, as they will save no fuel-use a lower temperature setting as a constant.
5. When the system has been properly vented, and balanced, then consult a good burner man on the dual fuel setup. At the end of #5, you will already be using 15-30% less fuel. The burner may be down fired, if you have short-cycling.
6. Insulate all the pipes.
7. Check the timing of steam arrival to the upper floors, and if too slow, a vent on the riser may be needed.
8. Fix the misc in the boiler room, making sure the boiler has enough outside combustion air.
if you have a 2-pipe system, check all the traps, which can be repaired with new capsules.--NBC

josepha

Thanks Nicholas! This gives me a lot to work with. It is a one pipe system. Will get some pics taken and post. Still catching up on some reading here as is a ton of good info here.. Thanks again!

josepha

@nicholas bonham-carter‌
Thank you again for the insight!

attached some pics of the boiler and surrounding

1. as mentioned, one pipe system. Where would be the best place to install the main venting or steam traps? I'm not sure I have any venting in the basement. Have only seen vents on the unit radiators (obviously) and at the top of the main risers on the top floor.
2. I think I will need to install a low pressure gauge (as I saw recommended somewhere). As you see in the pics I have the typical high pressure one that sometimes is difficult to read in the low range. Though when making steam, I usually see at 1.5-3.0 psi.
3. I'm going to check this next. I'm certain venting and/or pitching of the radiators can be improved. Recently when making steam, in the units the riser often sounds of water lapping.
4. It's actually worse than that. When I say honeywell, I mean the old rotary model without any remote sensor (to have some control) as last heating season the fuel watchman failed and is being bypassed. This is leading to (obviously) overheating and need to manually adjust always to compensate. This is why controls was at the top of the list for me (not necc for the save, but the immediate need). Could I really expect to run a system of this size off a thermostat w/ one remote sensor placed somewhere? I've been getting quotes for a heat-timer MPC platinum. Wouldn't I be better with something like that?
5. I'm obtaining quotes for new burner now (given lead times I'll be lucky if it completes for next heating season). Anything I should look for in burners to use (note: current oil burner is abt $1.68m BTU input/$1.47m out). Have been quoted options with the Carlin 702 g/o and a powerflame, any preference? Do they all allow variable operation (I.e. low and high speeds)?

I'm going to save 6, 7, 8 until I get the rest in check.

To add: Recent Service
- Cleaning / Vacuuming
- Repaired leaking tube
- Burner dampener motor was getting stuck and causing shutoff/back flow. Was resolved and cleaned.
- Rebuilt holby hot water mixing valve

Last added question - on a cold day, what should the typical steam cycle look like timing wise?


@Hatterasguy‌

I think you are right about the radiator vents, sure a lot are not performing properly. Going to try and systematically change in each unit.

One thing I notices in some of the lower units are that there are no radiators in some units (only risers) and there have been no complaints. On a second floor unit, there are two radiators, but the tenant has had the valved closed cause is too much heat. I suspect a rebalancing of sorts is worth a look, but hesitant to to start until I know I've got proper/consistent operation of the boiler.

For the tekmar, is this a remote ambient indoor temperature sensor only or can you use outdoor as well? Does it work with a condensation/return line sensor (or is that only the heat-timers)?


Thanks!

josepha

Hatterasguy said:

The tekmar operates off an outdoor sensor and calculates the run time based upon the ambient. The installer has many degrees of freedom to tailor the heating curve and the duty cycle. You can also use it with an indoor sensor which will, in theory, learn the curve for you, but I have not installed one.

It does have a condensate sensor which is placed on the dry return to tell it when to start the cycle. The preheat time is not calculated in the run time.

qq: do you really need a qualified installer to calibrate or is it fairly straightforward. would have electrician install/wire and I'd calibrate. Reason i ask is cause quotes I've gotten seem to be leaning towards the heat-timer (at much higher cost), though have been hearing good things about the tekmar. Only drawback I can see is that has no remote monitoring capability like the heat-timer MPC w/ internet.

Thanks

davidnyc

We have a 500,000 BTU Weil McClain, 5 apartments, Heattimer MPC (Green) is failing. Seems like it would be the cycle timer, but Will Bencomo who seems to have a business rebuilding heat timers says when it hangs at zero it's usually not the cycle timer motor.

Anyone have experience with his rebuilt HeatTimers?
Or better to switch to a new Tekmar 279?

Thanks