Steam Ramblings

hvacfreak2

So I think my system is complete , pipes , vents , oil components , trim , etc. I was able to do some performance testing this week with some help from the master ( @Steamhead ) via email. He has the ability to type a sentence that seems to be simple but will actually take you to a totally different area in the system ( this was regarding venting and time ). In the end I have concluded that " There is no replacement for displacement " , an old hot rodders saying. If I had it to do over I would go with the 513 , and probably complain about oil consumption. I am getting the mains hot and fast and after that the load starts to weigh down on the steam and requires some more " umph " to get the radiators hot. They do get hot , but it does take a little more time than it used to. All of this is based on cold start , I have not had any cold weather to really run this system hard yet . Muscle Car or the Tuner , I'm thinking I have a tuner.



With that being said I'm working on a digital control system to optimize what I have. The primary variables being when to fire and for how long. I do not mind some temperature swing either way , I feel that if I invested the energy to boil the water lets complete the process ( like a coal fire , it just seems too right ). So I'm going to bring in some information that I can view and play with some " this or that " logic and hopefully to my phone.



I finally got the Steamaster tablets to hold , saying that I finally cleaned my boiler / install I guess , lol. I enjoy reading the conversation on here regarding water quality as I never really thought much about it , and it makes such a difference. So that's where I'm at , thoughts appreciated.

BobC

Your going to use the most fuel when winter really sets in so having a boiler that is just about big enough should save you money when it counts.

Let us know how your new control strategy works out.

Bob

hvacfreak2

I'm glad I've had the time to tinker without being under the gun with the weather. It will be a little different operating than before , but I feel if I'm smart about it I can save a ton of fuel .

Question ; how long should it take to get hot water back to the hart. loop ? I understand that there is no specific number to place on this , I just wonder if I screwed up running 1 1/4 for most of it by adding some un-needed volume.

Jamie Hall

Sounds good! Depending on how your system is set up and runs, it may take quite a while for hot water to get back to the Hartford Loop. For example -- the place I care for has two very long wet returns (about 60 feet each) which are right at floor level in the basement. They never do get hot. Vaguely warm, maybe. Hot? no. Neither does the basement, for that matter!

hvacfreak2

Thanks Jamie , I had no clue what was normal on that. If I run long enough I can get it hot up to the Hartford but from a cold start on a regular cycle it's not even warm.

Chris_L

Thanks for sharing this info. I am very interested in how this works out, as I have started playing around with a microcontroller-based system for monitoring my small gas boiler.

I'm not familiar with Pokeys, and have been working with an Arduino to collect data for optimize main venting. (See attached pdf.)

A few questions:
1. Are you planning to monitor steam pressure? I've been looking around for a low-cost, low-pressure sensor. I've found this one on eBay, but wonder if anyone has any experience with it:
http://www.ebay.com/itm/Pressure-transducer-sender-5-psi-stainless-steel-for-oil-fuel-air-water-/251520321321?hash=item3a8fc78729:g:NAsAAOSwa39UuVqA&vxp=mtr

2. What kind of temperature sensors are you using and how do you attach them to the piping? I have several like this:
http://www.ebay.com/itm/400932351723?_trksid=p2055119.m1438.l2649&ssPageName=STRK:MEBIDX:IT
Note that with these, it takes a while for the temperature to peak so time the steam reaches a particular point should be measured based on when the temperature starts to rise. (And in my case I haven't been able to get good enough heat transfer to the sensor to even get up to 200 F).

3. I am curious how you will sense the state of the pressuretrol and low water cutout. Can the Pokeys connect to them directly, or do you need other hardware? (Since I have a millivolt system, I can measure the voltage directly with the Arduino.)

Thanks in advance for any additional information.

Chris

BobC

@ChrisL have you tried using heat sink compound between the sensor and the pipe? Also if you were to use a 3-4" section of rigid insulation to clamp the sensor to the pipe it might help.

Bob

Chris_L

@BobC, thanks for your suggestions. I've thought about using heat sink compound, but haven't yet. I did use some fiberglass batt insulation I had hanging around, and it helped.

If I decide to leave the temperature sensors in place, I'll definitely use the compound. For now, I am just using them to check the time it takes the steam to get to the end of the mains, as I try to optimize the venting.

(First I need to install the fiberglass pipe insulation that has been sitting in my basement since the summer when I had the asbestos insulation removed.)

hvacfreak2

Pokeys is a higher end Arduino , apparently they are a standard for industrial CNC machines among other things. I selected it mainly for the graphical programming package that is already in place. I'm sure that someone has written similar for some other brands but it was a one stop shop for what I was after.

I was not planning on monitoring system pressure , mainly because there is nothing I can do with it for what I have. If I was I would not go the cheap route on the transducer.

For air temperature stuff I am going I2C , because it seems like a solid bus with real network identification for the devices.

For the electro mechanical devices on the boiler I will energize RIB or PAM relays and use the contacts for the controller side. For burner status I will use a current sensing relay ( Hawkeye ).

I have not selected the pipe temperature sensors , I'll check your link in the am and thanks.

Chris_L

Thanks for all the info. I'll take a look some more at Pokeys.

As for that temperature sensor, it uses a Dallas/Maxim DS18B20 chip, which is widely used for measuring temperature in things like digital thermostats. It is supposedly accurate to within 1/2 degree C up to 85C and can be used up to 125C.
(I tested mine in boiling water and they were within 1/2 C).

Each chip has a unique address and they work on a one-wire bus. (It looks like your Pokeys is already set up for this.) So you could put all of your temperature sensors on the same bus if you wanted to.

hvacfreak2

Oh wow , that is cool. Talk about coincidence , I have been looking for those . lol ( last night as a matter of fact ). Go figure.

The DS18B20 is a " 1 Wire " Network Device. The Pokeys does support both I2C and 1 wire. I'm thinking I could use the air sensors as I2C and the pipe temps as 1 wire. I think it will support 8 on a 1 wire net.

Those look like they should work , for the price it's worth a shot. Conductive paste was mentioned and I might secure it with a metal hose clamp and wrap the whole thing in electrical mastic. Fiberglass over all of that.

https://www.poscope.com/pokeys-devices

http://microcontrollershop.com/product_info.php?products_id=5266

Just fyi this is about 20 bucks cheaper on ebay.

Chris_L

Yes, you can get these in bulk for a couple bucks a piece. For example, see:
http://www.ebay.com/itm/5x-DS18B20-Waterproof-Thermal-Probe-Temp-Sensor-Thermometer-Arduino-PI-ARM-LC-/161807236528?hash=item25ac767db0:g:em8AAOSwMmBVpmkC

I think you can use several dozen of these on a one-wire bus (if your microcontroller can supply enough power).

A couple things to note if you are using these on steam pipes. They recommend not using parasitic power at 100C and above. (Also if you have a lot of sensors and long wires.) And while the sensors are good up to 125C, the insulation on the wire was rated at only 85C on the ones I received. (Guess they aren't expecting this kind of use.)

hvacfreak2

10-4 , yeah I can only use the ones with external power and was surprised when I opened the link you had posted that they were what I had been looking for. If they wont hold I'll look into an analog converter for 10K ( Tekmar sensors ) , I know they will hold. Also I have not checked Digikey for any of these specialty sensors. Digikey has the nicer transducers also in case you were not aware.

Once I get a handle on a basic setup my next idea is a big one , wireless air valves for 1 pipe ( or at least networked ), lol. One step at a time .

hvacfreak2

Tonight's work , it's different to be doing this for myself ..I don't have to stop to ask questions.

hvacfreak2

Completed panel diagram minus grounding terminations. I have a real power supply that I thought about using but it costs twice as much as the controller.

hvacfreak2

<

Sailah

Interesting to see this here. I've recently purchased an arduino and raspberry pi and am slowly learning both. I will fully admit I have an outside party working on programming for me.

The DS18B20 is a cool probe. I have the 3' long versions and they are pretty accurate. In my case I'm using them for general temp measurement and don't need anything highly accurate. They have a unique ID so in my case I'm running a 8 channel ADC and can wire up to 8 unique probes for my Raspberry Pi.

I hooked mine to Ethernet at work and can log into my command window and monitor the data logging which is always interesting.

Chris_L

@Sailah, could you explain this statement: "I'm running a 8 channel ADC and can wire up to 8 unique probes for my Raspberry Pi"?

The DS18B20 is a digital thermometer so I don't understand the reference to the ADC. I don't know much about the Pi, and what its memory or power limitations might be, but in general you can put dozens of these on a single, one-wire bus.

So if someone really wanted to go crazy monitoring the temperatures of their steam system...

hvacfreak2

I wanted to use a Trane MP 581 for this originally , but I didn't have 2k for Tracer Summit or SC to do anything fun with it. I was amazed when I started looking at the generic ( non - BMS )hardware and what people were doing with these.

@Chris_L , the number of sensors that can be used on a controller will depend on memory resources available or allocated within that controller ( which you mentioned ). Mine says it will support 10 1- Wire and 8 IC2 , as well as some analog . But I see what you mean , maybe that " ADC " device gives him 8 channels ( so like 200 sensors ) ?

@Sailah , that is cool man you are a modern day mad scientist for real. Please keep posting on progress or developments on your set up , I'll do the same. The Pokeys block programming will help me get up and running quickly I hope . The C++ and # to get to my front end graphic ( and display real time data ) will take some time for me.

ChrisJ

Wouldn't an 8 channel ADC give you 8 analog inputs, so 8 analog sensors?

hvacfreak2

These are network sensors , " 1 Wire " ( developed by Dallas Semiconductor ) , microprocessor based. The 1 Wire network infrastructure will support a lot ( some number ) of devices.

ChrisJ

Dallas?
I thought Maxim bought them out years ago.

hvacfreak2

It may have been developed years ago and now ( past 5 years ) processors are powerful and cheap enough to bring it out ? I do not know much about it.

Sailah

Chris_L said:

@Sailah, could you explain this statement: "I'm running a 8 channel ADC and can wire up to 8 unique probes for my Raspberry Pi"?

The DS18B20 is a digital thermometer so I don't understand the reference to the ADC. I don't know much about the Pi, and what its memory or power limitations might be, but in general you can put dozens of these on a single, one-wire bus.

So if someone really wanted to go crazy monitoring the temperatures of their steam system...

Sorry I was confused by my own picture. I am running different analog inputs to my raspberry pi. The pi doesn't accept analog signals so I ran it through the ADC. The temp probe is the thick black wire and it runs its digital signal to the GPIO pin 4. I'll be adding 2 additional analog inputs and 2 more temp probes to the Pi. My analog input is the duplex red wire, goes through a resistor and then to the ADC.

I'm the last guy that should be playing with computers but it's needed for a data logging project we are working on and I'm the most tech savvy guy here. Which is downright pitiful lol.

I will say I spend a couple hours at night and in the very early parts of the day watching videos on arduino and raspberry pi programming and it's been very helpful so that I can communicate with my programmer. The Pi is amazing what it can do for so little money. But if you are a complete Luddite like myself it's daunting to navigate through computer programming at a high level.

hvacfreak2

ADC analog / digital converter ( long day ) . It seems that none of these things do any true " analog " like we're used to. I think mine has 4 adc inputs.

BobC

@Sailah I've been playing with the Pi for a few years and your right about it having a lot of power in a cheap little package.

Take a look at this project from adfruit .

Sailah

BobC said:

@Sailah I've been playing with the Pi for a few years and your right about it having a lot of power in a cheap little package.

Take a look at this project from adfruit .

Thanks bob. I got my probes from adafruit, they are a great resource. I tried to follow that lesson and gave up a few weeks ago when I got the Pi.m The guy who is writing my program for me is awesome. He's been a huge help for someone with zero skills in programming.

I'm thinking about getting another Pi with a display and doing the desktop weather station that gets its data from NOAA.

Similar to this I think would be fun to have in the kitchen with 2 young kids, of course my phone does the same thing....
http://www.instructables.com/id/Raspberry-Pi-Internet-Weather-Station/

Chris_L

@ChrisJ, yes the 8 channel ADC would give you 8 analogue inputs (I think). But my point was that the DS18B20 is a digital sensor, so it doesn't need an an analogue input or an ADC.

You connect one or as many as you have to a single digital input on your Pi or microcontroller since it uses the one-wire protocol.

And you're right, it is Maxim now but people still refer to these as Dallas sensors.

hvacfreak2

Dallas Sensors , you know that there is a conversation going on in some upscale bar right now with a guy in a white suit and smoking a cigar saying " Technology , hrmph , I made my money and got out of it ".

hvacfreak2

The Pi is amazing what it can do for so little money. But if you are a complete Luddite like myself it's daunting to navigate through computer programming at a high level

I'm glad I don't have to start so far down as to be staring at a blank screen with C:\ staring at me with this , mine is ready to go so far as reading values to the controller.

Sailah

Me too, I'm reading temp as well as a few other things. I have the Pi remoted into my desktop so I can read what is going on from my office. Mine saves the data it reads every second in a 24 hour period into a CSV file that I can graph in Excel.

I have it hooked up 24/7. My programmer has made a webpage for me that I can adjust the thresholds so if the readings fall below a certain level it won't bother datalogging.

hvacfreak2

Sweet. Man I'm falling behind , where are my parts !!! lol. The good lord is delaying winter for me , 70 by the weekend. I could start programming it , just procrastinating really. It's been tough to get in the right mindset this week , work has been intense.