Steam control for 6-unit NYC loft building with high wind load

axlloyd

Hi, I've been lurking here since reading We Got Steam Heat and am ready to seek some advice directly.
I'm the president of an 1860s 6-unit loft coop in NYC. We have a single steam boiler, and a mix of 1 and two-pipe stacks. (I would also love a recommendation for a smart steam person prepared to make multiple visits to Manhattan to help with balancing, but that wasn't the main point of this post.)
We have a Heat-Timer MPC Gold. I've done all the obvious tweaking, but it is fundamentally doomed in that it has no idea how much heat the building is losing to wind/infiltration, nor how much heat the building is storing from recent weather. Both of those factors have a huge range that is not really taken into account in the Heat-Timer's model.
I often text with the neighbor at the end of the run, think about how my apartment feels, check the weather, and then adjust the Heat-Timer. This is silly. I'm convinced we need a system that takes the indoor temperature of multiple units into account. There's a lot of room to be more comfortable with less oil.
I've ruled out Tekmar because I don't only want heat suppressed when the building is too warm, I want heat supplemented when it's windy and heat loss is greater than the model assumes.
The building is probably about 90 feet high, in a noisy RF environment, so I don't expect a normal home thermostat with wireless sensors will be able to reach. I'm also hazy on how they incorporate multiple sensors.
The two options I've come up with so far are the ESI AD 2000, and Heat-Timer MPC Platinum. Both ar expensive, and with different drawbacks.
- ESI: Lots of control how the various sensors are weighted and when outliers get excluded. Owner able to answer all my questions about how it works. Requires wired sensors though, a big hassle to arrange access and installation for. Limited east coast distribution also implies limited familiarity from local contractors when I'm not around.
- Heat-Timer MPC Platinum: Has a wireless sensor option with repeaters, and their installers will do a wireless survey and figure out where to put them. Sales guy not able to be very precise about how the sensor data is incorporated, other than that it is averaged. He claimed outliers get dropped but there is no mention of that in the manual. The "indoor temperature target" interacts with their old algorithm in ways that are not at all specified in the manual, making me wonder to what extent it's an afterthought bolted onto their old model. Even more expensive.
Are there any other options I should be looking at? Experience with the two choices above for this application? I've seen a few people rave about the ESI system, and if it didn't require hard-wiring I'd probably just do it.
I wonder if there's any system that's more like a traditional thermostat, but with modern repeatable zigbee-style sensors and the ability to thoughtfully incorporate multiple of them?
Thanks for any tips.

SeanBeans

@JohnNY is the only one NYC I can think of.

ScottSecor

In your case I am not convinced they make a control(s) that will accomplish what you wish for.

I have yet to see a steam control that takes sun, wind, shade, etc. into account and I've been in the heating business for over thirty years. Most controls (Heat Timer for example) try to determine how long it takes for the seam to reach the end of the main, or how long it takes for the last radiator on the longest run to get hot. This is certainly better than nothing, but what happens if most of the other radiators are already overheating the apartments that are closer to the boiler? In most older steam heated buildings that we've worked at the heating systems are rarely original (pipes, radiators, traps, angle stops, partityion walls, etc). What I'm getting at is the "Dead Men" installed the best heating system they could for the time period, but today that system may not resemble the original system. Today, the surrounding buildings may not be the same ones that were there back in the 1860's. Perhaps a newer building provides shade that was not there originally. On the other hand, maybe there is a small park next door that used to be a heated building that was attached to your building.

In your case, I think thermostatic radiator valves (TRV) on each heat emitter (likely radiators) might be as close to perfect as you can get. It will give each occupant better control, as you know not everybody wants the same temperature in their unit. Danfoss for example makes a TRV for two pipe steam and a unit for one pipe steam. Based on your post (and many buildings we've worked on over the years) I would think if you fitted every radiator with a TRV, the comfort of the building would get much better while the fuel usage would drop substantially. What we've seen is instead of 90 degree hallways and 60 degree bedrooms, the whole building is within a few degrees of 70. Not perfect but certainly acceptable to most people, especially if when their contributing directly for the cost of the fuel!

One more thing to consider, assuming your boiler is properly sized, is the burner fully modulating? In other words, does the size of the flame automatically decrease when the steam pressure in the boiler starts to increase? If not consider having a modulating burner installed, it will decrease short cycles, provide more even heat (I'm guessing the building was originally heated with coal, that often fired non-stop when it was bitter cold). Finally have someone confirm the boiler is sized properly for the load (EDR).

JohnNY

I work with Heat-Timer a lot. Their manual doesn't tell you to ignore outliers but it's in the options when you get to your dashboard.

axlloyd

Sorry I didn't literally mean that it should directly take wind/shade into account, just that it should make its decisions incorporating the effects of those influences. Notably by incorporating indoor temp.
(Tangent: my office building installed automatic shade controllers that are driven by a sun sensor on the roof and a model of light angles according to date. There was a big rebellion and everybody got their offices one by one unhooked from the automation.)
Somebody had advised me that TRVs are a bad idea with steam, but I don't remember why. Any particular caveats I should watch out for?
We do not have a modulating boiler. It's an on/off oil burner nearing the end of its life. We'll definitely evaluate sizing whenever it's time to give up on maintaining the current boiler.
I just dug up some old email, and John actually did a walkthrough of our building in 2014. We implemented some of his recommendations. I should look for time to get back in touch.

question

My suggestion is to master vent each riser to vent quickly and use trv's on each radiator. You can try Paul Shay from A Real Good Plumber. He has done work for me and I am very satisfied. his web site is https://arealgoodplumber.com/

I have been using US Energy Group for the last 9 years. They guaranteed a 15% saving in fuel back then. There website is http://www.use-group.com/

Good luck

axlloyd

Thanks for the links. Googling about master venting also turned up this nice summary of options compiled by an NYC efficiency agency.
https://retrofitaccelerator.cityofnewyork.us/sites/default/files/public/BEEx Case Study_Better_Steam_Heat_Playbook.pdf
(A more stable link might be https://retrofitaccelerator.cityofnewyork.us/steamheating.)