I have a unique set of skills that make HVAC a lot of fun for me. I have been a programmer my entire life but I also work in the HVAC industry giving me a unique perspective on all the ‘smart things’ hitting the market.
Taking my knowledge of HVAC and my skills as a programmer I recently began programming my own MCU’s to control my radiant in floor system.
Over the next month I intend to finalize my radiant in floor ‘smart control’ and I will be tracking my progress here on my blog. I should be clear that this is a hobby but when completed it will be as polished as I can make it and hopefully somebody likes the idea so much they take it over and make it a reality for more than just my in floor system.
- Bring the Smart Thermostat trend to Radiant: The company I work for sells one of the premier brands of radiant in floor systems but controls in general for hydronic systems are lackluster at best. Why is there no wireless options? Why cant I control it from my smart phone? My control is both wireless and internet enabled
- It must have a small footprint. As of right now my wireless radiant control is the size of a deck of playing cards or slightly larger than my business card.
- It must be standalone. I feel that a radiant control that requires a computer is a tragedy. My system does not require a computer it is completely stand alone and can be installed anywhere in a building. Every 3 seconds it reports data to a cloud server which you can access from your smart phone or computer but no computer is needed to power or run the system.
- It must be mobile. Currently I am powering mine off of a battery and given its tiny size it is VERY portable. Batteries have serious limitations but I have spent a lot of time and research and I should be able to power mine for 2 years based off the power consumption of the system as it stands ( about 3480 milli volts )
- It must have WiFi access / Local Backup: My system has WiFi access and all the data that it collects is stored securely on the internet. My system also has an onboard SD card which I will in the future use as a local backup for all the data that is currently being stored in the cloud.
- It Must be Affordable: If you are going to build a smart control for radiant systems it does nobody any good if you can not afford it. My goal is to have a radiant smart control system that can be built by Engineers or über nerds for under $300.
How the System Currently Works
If you are familiar with a Taco ZVC control box my system works on a very similar premise. The system currently has 4 inputs ( temperature readings ) for four separate zones and those in turn energize one of 4 relays which will in turn energize the pumps ( or actuators ) for each zone. The relays for those wondering are rated up to 10 amps at 250volts which is more than competent for my project or yours.
I have set up automated email alerts that notify me under the following conditions;
- If the system looses power or the battery backup is going to die I will get an email
- If the zones are not heating correctly or loosing temperature drastically I get an email
- If the zone has lost communication with the server I get an email.
On My Roadmap of ‘Things to do’
I have put a lot of time into my Radiant floor Smart Control and I have already managed to program in some very interesting ‘gadgets’ have no real world value as well as some cool features I think make Radiant in floor system operation more innovative. A few items on the very near roadmap are;
- Enable Alerts When System Goes Offline: I need to fine tune how I am going to do this portion but when my system looses internet access or does not report any data in a given period it will send an email so you know the system is offline.
- PID Control: I am going to add a proper PID control to my temperature sensors so that it will efficiently get to the set point. I have the code just need the time to implement it.
- Max / Min Floor Temperature: I will be adding in min/max floor temperature settings to the controller to make sure that my floor is always comfortable but that it is also not ever going to overheat the floor which can cause damage and discomfort. Nobody likes a hot floor.
- Launch a Website for the Project: I intend to launch a Site for the online portion very soon so that anyone can see the data that is being collected.
- Make the System even Smaller: I have already found a smaller MCU which I can hopefully program and achieve what I have done already with an even smaller footprint. The new MCU is just about the size of a small pack of matches which is exciting to me. It also costs half as much as the prototype I built.
That is all I have for now but I will continue to update and add new blogs on this topic as I make progress.