Currently I am working on a Measurement & Verification system for a commercial solar thermal pre-heat system.

I would like to employ the Haystack naming convention as much as practical to identify each temperature sensor.The system has a closed loop from solar panel to heat exchanger. And an open loop from utility supply to heatexchanger to boiler.

A few questions - is the tag hot superfluous?; I sue solar to differentiate the closed loop side. OK? I'm curious as to the Haystack word order. For me it seems more readable to have point, medium (hot water) flow direction and origination/destination id. Rather than medium, flow, direction, i.e. chilled water leaving temp sensor.

Suggestions/clarifying comments would be most welcome.

temp sensor solar hot water entering heatexchanger

temp sensor solar hot water leaving heatexchanger

temp sensor hot water leaving heatexchanger

temp sensor hot water entering heatexchanger

temp sensor hot water leaving boiler

temp sensor water leaving utility supply

temp sensor solar panel

I believe we've had a few people who have done solar projects (not sure if they were hot water).

My comments:

1. overall those point tags look good to me
2. I would suggest camel case for heatExchanger
3. do we want to model the heatExchanger itself as an equip? What tags might we want on the equipment level?
4. not being familiar with this, what is different b/w "solar hot water leaving" versus just "hot water leaving"? Is there two piping loops? Can you describe pipling connections and flow b/w heat exchanger, boiler, utility?

As points don't normally exist as global points on a site, I think you have to start with a discussion about what equipment needs to be modeled (as Brian suggests).

The solar panel seems a likely candidate with entering/leaving water temp (could be entering/leaving air temp for a air system) as well as the internal panel temp. Panel temp could be internal air temp or perhaps some physical object temp like plate temp.

The heat exchanger is a little trickier. In some cases it has its own entering and leaving temperature on each side of the heat exchanger in which case they would be their own points. In some cases it is just the temperatures from some other device like your case of the solar panel and another loop. I have a similar situation in a water source heat pump building where I treat the central loop as a piece of equipment with entering and leaving water temps. I do the equivalent of an ahuRef on each heat pump back to the loop to get entering water temp to the heat pump since I don't always have it on each individual heat pump controller. I don't even model the heat exchange as a piece of equipment. It is more of a virtual piece of equipment by looking at the loop temperatures and the cooling tower temperatures.

I would lean toward not including equipment type tags on the point names and using the atomic tags already defined (air, water, entering, leaving). The solar panel my warrant an "internal" tag to distinguish internal panel temperatures from the heat transfer media flowing through the unit. I also wouldn't introduce a "hot" tag. That should be implied depending on the type of equipment and the function it is performing (heating or cooling). It would be up to the application (controller or analytics software) to implement logic to determine what points should be used from the appropriate piece of equipment including logic to walk through a hierarchy of equipment until it finds the most relevant point.

I hope this adds some color to the conversation.

Re: Brian's responses - The application is to model a real-world system to better design commercial solar hot water systems for specific applications. Typically standard (boiler-based) hot water systems are designed to peak (maximum) load - at 8 am 25 guests will be taking showers and the kitchen dishwashers will be running. This design emphasizes flow rate and recovery (how quickly can x qty of water be brought to y temperature). Solar thermal systems, especially this particular installation type, are focused on balancing storage and demand - in a given environment is it better to upsize the storage tanks or the collection area. A real-world demand profile answers this question.

heatExchanger parent is solarThermalcollector.

solarHotwater leaving is leaving solar array. Hot water leaving is leaving heatExchanger or boiler. The first is a closed loop - leaves utility supply, enters solarThermalcollector, leaves to (enters) heatExchanger; leaves heatExchanger enters solarThermalcollector - in a loop.

waterSupply leaves utility; enters heatExchanger; hotWater leaves heatExchanger; enters boiler; leaves boiler (is consumed or recirculated)...

re: Paul's response The tricky part of the heatExchanger is that there are two entering and leaving loops; the "closed" side back and forth between the collector and the heatExchanger and from the utility to the heatExchanger to the boiler.

The WSHP example is appropriate but I don't understand the naming convention well enough to understand how to employ the ahuRef example.

Is it as simple as... temp sensor water entering heatExchanger solarThermalCollector #closed loop temp sensor water leaving heatExchanger boiler #open loop

Thanks for your help.

Based on feedback from Brian & Paul - here's the latest draft...

temp sensor water leaving utilitySupply (entering solarThermalcollector)

temp sensor ambient outside solarThermalcollector

solarThermalcollector temp sensor water entering heatExchanger

solarThermalcollector temp sensor water leaving heatExchanger

boiler temp sensor water entering heatExchanger

boiler temp sensor water leaving heatExchanger

boiler temp sensor water leaving boiler

Well guys I am trying hard to get my first solar power system for my home.. Cay you guys guide me the best affordable brand..

I am confused about the comment "entering solarThermalcollector"

temp sensor water leaving utilitySupply (entering solarThermalcollector)

I think the "water leaving utilitySupply" would enter the heatExchanger on the boiler side not the solarThermalcollector side.