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archibald tuttle

Jay Vath from Watts Tekmar division is looking at an update to the 279 steam control. under current circumstances as a one stage controller it is really hard to justify the high unit cost rather than simply use the thermostat and a large differential for cast iron as a flywheel (assuming mostly cast iron radiation). But with continuing interest in efficiency across even niche platforms they are looking at multi-boiler or staged valve control with a vapor pressure transducer as input instead of just the condensate temperature trigger.

Both the potentially improved system information from a transducer and the staged control would make me a more likely customer for this line. Still will include logic to relate system peformance to outdoor temperature as well.

Jay asked how many stages I have seen in the field and my own experience has largely been with two either through two stage gas valves or two boilers.

If it were ever to enter the affordable realm there is the powerflame X4 option for modulating fire gas that would need variable output based on transducer readings but I without control options I don't know of anyone who has tried that route yet. Still I want to encourage Jay to take input from professionals. It would be a shame if there is one major redesign and it orphans the possiblity of bringing foward innovative repowerings on modest size steam ,e.g. 250,000 to a million or two.

I think it would be good practice, appropos of the 737 max to maintain a condensate temp sensor so that transducer and hot return compared to outdoor temperature operation could allow for the previous 279 style of operation of the hot return is triggered without a pressure indication, given the difficulties in sensing pressure at such low levels. They will obviously need to test sensors in various installation configurations, maybe some 'combat' installs as well as they get the service life and effective long term operation dialed in. I recommended they consider working with Dwyer who I consider to have the best vapor sensing at the moment but even there they are going to need good inputy from steam professionals because Dwyer has never really considered the application to steam of their vapor sensing line - or at least had not when i spoke to them about it a year ago.

Come to think of it, I think they could put a stack temp sensor as well because i bet you can begin to pinpoint making a certain amount of steam at a certain temperature against a certain stack temp to have even more information regarding cycles and firing rate or stages if the precision of the pressure signal proves difficult to maintain.

So I got my 2¢ in, but this is an effort that could use input from the complete range of professionals accessible here (along with whack jobs like me). As with many markets at AHR they are sensitive to the idea this could be a market generated by government efforts to regulate energy consumption. That is the most disappointing part of this for me. If this equipment saves energy and is aimed at a payback, that is what I care about. I understand there are some folks who can't see it if the pay back is not experienced in a year or two but it is our job to help them understand medium term rewards as well as being around to demonstrate that they actually get those, rather than have uncle sam or the state of california, when it stops making the list of things it uniquely knows cause cancer, compell a different result.

Also, I think the ability to monitor and maintain the system that is equally inherent in better digital logging of multiple parameters of the steam cycle, as well as real time system information that means that the payback is not just in energy savings but in operational and diagnostic efficiencies as well.

Brian

Steamhead

So, what are they looking for here, @archibald tuttle ? Possible test-beds? I think @Gordo and I could come up with a few................

archibald tuttle

for now I don't want to overwhelm Jay Vath but give him access to our blue sky on what is needed on a steam control. They are only going to make one and i would like us at the table before they roll it out, instead of afterwards to complain about what it doesn't have.

They might need real world test bed eventually although i think getting a wish list on the wall is a good start to open some dialogue. they are surely going to blackboard and bench a bunch of ideas before they go out in the field to test.

one area of really important feedback is going to be good sensor and good sensor location understanding the need for precise signal but some extent of environmental isolation depending on how tolerant of the steam environment it can be made. in my active testing of setups i've been going combat with a 4 foot dead end 1" tree to a brass adapter for the plastic hose output to my UEI meter. That seems to give very reliable results through a half dozen cycles without carrying damaging system environment to the 'digital gauge', i.e. test meter, but don't know if eventual humidity occupation of that pipe spells long term path for damaging temps or moisture or how resistant a sensitive transducer can be. I should side by side that with a loop and calibrated instruments to see the relevance the loop for readings. It could just be lousy controls that have lead me to believe for years that i'm not reading well through loops because theory says it should work. Maybe there is a relevance of the crosssection of the loop with various real world frictions involved. These are the kind of things that could be figured out on a bench for a while but then confirmed in dirtier real world installations.

There has not been a lot of engineering around this question with most vapor pressure gauging and testing equipment I've found being developed to monitor airflow in ducts rather than aimed at our uses reflecting higher temperature and humidity.

Then there is the question of the marginal cost for additional features, e.g. maintaining condensate temp. sensor with addition of pressure sensor, stack sensor, or others desired, and outputs e.g. how many stages are ideal and what is the marginal cost of including 3 or 4 if the vast majority of utilty is 2. desirability of variable outputs for modulating either inputs or loads. for that matter, what about one or several inputs for conditioned space to inform the algorithm. And what will be the addressable parameters.

and then there are the market questions. Without putting competing distributors up here down to the dollars and cents level, i have more macro dollars and sense reality in mind that this control is currently cruising a grand. Really hard to justify in most applications I service for what it currently does. With it being redesigned, if it can replace the function of other controls, e.g. especially vaporstat, and has utility across a range of small to large residential and commercial applications could there be enough of a unit market to make this a more universally affordable approach – a lot more features without pushing the price up and even the potential for moderating pricing a little if the installed base starts to increase significantly.

One can envision there might be a small market for larger buildngs that might get caught up in some kind of carbon control regime, or god forbid they actually can do the math and would see comfort and energy cost savings. But I'm hoping to avoid this constant tug of war between simpler less fully effective 'residential' controls and orders of magnitude higher priced 'commercial' pitched strategies, because steam is a small enough niche to begin with.

Also a fully featured control could inspire more work on staged fire or staged boilers or moderating fire that have never really entered the realm of possibility for the 'everyday' steam market.

brian