outdoor temp sensor/ Boiler reset control for steam boiler?

I've seen these boiler reset controls to sense outdoor temperature to compensate for the water temperature flowing through hydronic radiators. Just curious do they make anything for a 1 zone steam boiler?

This is for a 6 family apt building in NYC. I'm wondering if they make an outdoor temperature sensor that can prevent the boiler from coming on if it's warm enough outside. Current rules in NYC are:

From 6AM-10PM, indoor temp must be 68deg if outside temp is below 55. From 10PM-6AM indoor temp must be 55deg if outside temp is below 40.

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So I would need something similar to a programmable T-Stat for the different times and temperatures. I'm wondering if its possible to wire 2 T-stats in series?

Or will this cause more problems? Ideally, I'd like to have a Wi-Fi indoor T-stat , but there is no Wi-Fi in the bldg ( not even with tenants), and the wiring from indoor T-stat on 2nd floor hallway to boiler is insufficient ( only 2 wires).

Reply to
Mikepier
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Apparently they do, like this:

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I think it's more complicated than just two thermostats in series.

It's not clear if you're living there, this is for you? For one apartment? A common area?

But for the 2 wire to 2+N problem, Google is your friend:

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Reply to
trader_4

Mike:

Indoor/Outdoor reset controls are available for both hydronic and steam heating boilers.

But I think you're missing one important point. Apartment blocks are built different than houses. Houses have lumber exterior and interior walls that have very little thermal mass, so the furnace or boiler can raise and lower the temperature of the house relatively quickly. Typically, apartment blocks will have to abide by a different construction code and will have concrete block exterior walls with a brick veneer to make them look attractive as well as concrete block walls around each apartment to act as a fire barrier to prevent fire from spreading laterally.

It's the thermal inertia of your concrete block walls that would prevent any boiler or boiler control from being able to follow those 24 hour temperature guidelines you quoted. You can put in an indoor/outdoor reset control, but it certainly wouldn't be able to modulate the temperature in your building on a 24 hour basis like that. So, in that regard, you'd probably be best off to install an indoor/outdoor reset control, set it to provide a comfortable temperature inside your building and leave it at that. Trying to change the termpature of all that concrete every 12 hours or so is simply not going to happen. Your boiler control may be set to do that, but the thermal inertia of your concrete block and brick walls is going to be a monkey wrench in the machinery of it all, and will prevent your plan from actually working as hoped.

Tekmar is a well respected name in hydronic (and I suspect steam) heating boiler controls. They are owned by the Watts company which I believe is headquartered in the USA.

Reply to
nestork

Really??? How about the hundreds of thousands of homes built from other materials? Stone, block, ICFs SIPS. brick. adobe, concrete, etc.

Why? It only matters getting the temperature up at the required time, lag to the lower is not a problem, not does it have to go that low. You will have to anticipate the time for increase and the boiler will have to come on before the required time to reach the daily minimum for daytime.

You can put in an indoor/outdoor

It does not have to reach the 55 degree at night, that is a minimum. He can set it to whatever works and makes sense. I'd think that 62 or 64 minimum would be better in many respects. Happy tenants and easier to maintain the swings.

Reply to
Ed Pawlowski

I was waiting for someone to bring up the ridiculous 55 temp. That might be acceptable on an emergency basis, for a few days. But you'd have to be a slum lord to deliberately target 55F as an acceptable temp, just because the govt says it's as low as you can go and still not get fined, etc. From a practical standpoint, if you have it at 68F at 10PM, for typical building, it's not going to get to 55F, unless it's some place exceptionally cold or purely insulated, etc.

And I think Mike is conflating two different things. One is just setting back the temp at night. I guess you could screw with it more, basing it on outside temps, if you're really going to go to those guidelines. But IDK anyone that wants to live that way and I wouldn't do it to tenants . I'd have a min temp for day and a min setback temp at night that didn't depend on the outside temp. So, all you need is a setback thermostat that is secure and tenants can't screw with. How you do that, IDK. Plenty of tenants have enough smarts to figure out how to bypass stuff.

The main purpose of the outdoor temp reset, AFAIK, is to moderate the temps that the boiler runs at. At least that's how it works with hot water. If it's 45F out, you don't need to run the boiler water as hot as you do if it's

10F out. That lets the boiler run a little more efficient. AFAIK, you can still set the individual thermostats to whatever you want. Also, IDK how this concept works with steam, because you do need to make steam, not just heat water. But apparently the reset controls do exist for steam.
Reply to
trader_4

No the reset control doesn't compensate for the water temperature in the heating system; it lowers the set temperature of the heating system when it's warm outside and raises it when it's cold outside.

Also, I'm not sure there's such a thing as a indoor/outdoor reset control for STEAM heating systems because I'm not sure that steam boilers are set up to produce varying temperature steam the way hydronic boilers are set up to produce varying temperature water. Any steam boiler manufacturer could answer that. Maybe contact Weil McLain in that regard. They make hydronic boilers, but I don't know if they make steam boilers.

Ed Pawlowski;3289628 Wrote:

Ed: The heavier the construction materials used to build the home, the greater the thermal inertia. If you have concrete block walls in your house, you'll have the same situation as an apartment block where it takes a much longer time for the building to warm up or cool down because of the thermal mass of the walls. That's just a matter of physics and thermodynamics. The heavier the mass, the more heat it stores and the greater it's thermal inertia.

No. You're suggesting that he can program his timed thermostat to come one earlier and shut off earlier to account for the thermal mass of the walls. You could do that if it was just a few hours that the walls remained warm or cool, but we're talking days. How can you program a 24 hour thermostat to come on and go off several days in advance?

What I'm saying is that it makes no sense to have daily swings in temperature when the thermal mass of the walls is an important factor in the heating of the property for more than 24 hours. He'd be better off to just set the reset temperature control at a comfortable level and leave it that way 24/7 from October to March. That's the way most hot water heating systems with indoor/outdoor reset controls are operated.

Reply to
nestork

I guess it depends on what he meant by compensating. An outdoor temp reset systems does change the temp of the water flowing in the system based on outdoor temp. I'd call that compensating.

I wondered the same thing. I provided a link to a company that is selling them. Exactly how they work, IDK. It apparently applies some of the same principles to a steam system.

Just because there is more thermal mass doesn't mean that the same principles don't still apply. If you setback the temp in building A from 70F to 60F at night and it gets down to 60F at some point, before having to rise again you save money. And if in building B you do the same thing, but because of more thermal mass, it only gets down to 65F, you still save money, just not as much.

Reply to
trader_4

The T-stat is in the hallway of bldg., it controls heat for the whole bldg. I do not live there.

So this fast-stat device, looks like a multiplexer, correct?

Reply to
Mikepier

All I'm saying is that if the OP would be largely wasting his money on a programmable indoor/outdoor reset controller if his building is concrete block construction. The heating system simply cannot change the temperature of all that concrete by 10 degrees F every 24 hours, and (provided tenants leave their windows closed) the concrete won't cool down by 10 degrees F within 24 hours. What the OP wants to do is analagous to measuring with a micrometer, marking with a piece of chaulk and cutting with an axe. If he has concrete block walls, the thermal inertia of the walls is going to obliterate any programming he does anyway.

Reply to
nestork

Correct, but you stated houses were built of wood. Some are, some are not.

To maintain a day/night he can easily do only that with a thermostat. The only additional thing he needs is a thermal switch so that if the outside temperature is above some pre-set number, the boiler does not start. There are controls available depending on how sophisticated you want to get.

There are Honeywell thermostats that actually learn how long it takes to get up to temperature and adjust the start time accordingly. It does not have to adjust for thermal mass to cool down as it does not matter how long it takes, He even has the option of keeping 68 all the time if he should desire.

That is probably correct. With the thermal mass he is unlikely to get down to the 55 minimum, but if it stays mid 60 he will have happier tenants and at reasonable cost..

Reply to
Ed Pawlowski

I don't know more about the hydrolic boiler but you can adjust temperature in steam heating boilers buy using sensor. May there are some functions in hydrolic boiler also but i don't have more information about it. 'What your stock broker doesn’t want you to see'

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Reply to
stockbrokers

True, but who cares. The only thing critical is maintaining 68 as a minimum during the day and whatever it drifts down to at night as long as it does not go below 55.

What the OP wants to do is

Maybe the OP will chime in here, but I think he just wants to abide by the law and maybe save a few bucks on fuel. I think you are overly concerned about thermal mass that is going to work in his favor.

Reply to
Ed Pawlowski

Yes, it uses some kind of protocol to send signals down 2 wires to turn it into what is effectively 3 or more wires on each end.

Reply to
trader_4

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