two devices, one outdoor sensor?

Paulypfunk

Hey gang,

Installed a TT solo 110 that is using the existing outdoor reset sensor.  I am also adding a Taco I series mixing valve that has it's own outdoor sensor.   Is there anyway to use the same outdoor sensor for both applications without putting a second one outside?

Thanks for your help.

SWEI

Unfortunately not

Thermistors need voltage applied across them, so they can not be shared by multiple controls.  Also, TT uses a 12k thermistor while Taco uses a 10k.

Harvey Ramer

Sensor Modules

That's what we need. A module that can read a couple strategically place sensors and convert the signals to multiple different selectable outputs for the all of the controls.



How easy would that be! You could do it with a PLC but not cost effectively.



We also need a control built to accommodate radiant heating/cooling systems. I hope somebody steps up to the task but soon!



Harvey 

SWEI

Open protocols

could easily fix this, but they would temporarily eat into the profit margins of some very big players.

Harvey Ramer

No nice on the ice!

If I were in position to do it, I would make it first and smile all the way to the bank.



Harvey

Tim Doran_4

Sensor Sharing Device

I created one about ten years ago when I was with Uponor. Couldn't get any support to offer it. If I can get enough interest here I will bring it up with the electronics guys at Taco. One catch is that all of the devices would have to work on the same type of sensor.



Tim

Harvey Ramer

So...

Say you had one device that used a thermistor type temp sensor and a device that used a thermocouple type temp sensor. Is that what you are saying couldn't be tied together in a single sensor module? Or at least not economically?



Also while I have your ear, what would it take to convert the I-series valves so they can do both heating and cooling with all the desired functions? That would be a big winner in my opinion. Solve a lot of problems!



Harvey

Tim Doran_4

Different sensors

The board that I developed worked with 10K sensors. It had a main reference input and four outputs that would replicate the reference signal. Boards could be in series to get more outputs if needed. Sending to controls with different reference values is not possible unless the control has a input calibration feature.



As far as cooling with the i-valve goes I think it would require a code change. What applications would this be of benefit to you on?



Tim

Harvey Ramer

Useful

The board you built would be very useful in my opinion. Especially in Biomass systems. With those you have lot of sensors.



If you converted the I-valves to do both heating and cooling, we could add radiant cooling to existing systems making almost no changes to the piping. I could envision the outdoor reset valve being setup to also provide sensible cooling in a radiant system. It would need some sort of enthalpy sensor to be able to maintain a water temp above the dewpoint.



I recently installed a 17,000 sf radiant system that is setup with a minitube configuration and uses I-series for injection control in remote manifold stations. It would be awesome to add some cooling to it!



Harvey

Tim Doran_4

Radiant cooling not so easy

There is a lot more to radiant cooling than just circulating cool water as you suggested. The control sequence must include space dew point calculation and a provision to maintain the SWT into the system above the space dew point to allow for a reasonable safety margin. If multiple spaces are served it must calculate based on the worst case. Our iWorX control system can handle all of this but it would be tough with the iValve.



Tim

Harvey Ramer

Radiant Cooling

I know Radiant Cooling involves a lot of details. I did not feel the need to spell them out because I figured you already knew :-)



The I-valve was just a suggestion. The fact remains, we need a simple, residential control that handles heating and sensible cooling and latent cooling. It should be able to utilize the same piping and mixing controls for both heating and cooling. If a product like, Air Cells, are used for latent, the dewpoint could be accurately ascertained with a sensor in the return duct, since those fans operate on constant circulation. 



If properly implemented it should, in fact, bring down the total cost that consumers currently pay for 2 separate systems, Radiant for heat and an Air Condition system. I really see no good reason why the industry as a whole should not move in that direction.



Harvey 

Steamhead

Maybe

some of the outputs could use a DIP-switch setup to match them to different units.