In earlier blogs I wrote about the heating control prototypes from Telepure which became OWL. Things have moved on in a big way and I have just installed the complete, integrated product set consisting of wireless optimising thermostat and energy monitor.
By pure coincidence as I was writing this I saw an ITV programme “How to cut your energy bills”. Not just a plug for switching but showing the potential savings for families who have not thought a lot about this. Quote: “You can save as much by changing your heating controls as you can by changing all your windows”.
Network OWL – the bridge to the Internet
Room thermostat (single zone)
Tank thermostat (single zone)
Boiler relay (makes room stat completely wireless)
Energy monitor for grid and PV system
This can be extended with multiple zones as and when I add the extra plumbing.
This is all managed through my account dashboard on the OWL website. There I can easily adjust the settings and see real-time graphs of the system’s performance. A slightly-reduced set of controls and displays is available on the free smartphone apps for iPhone and Android.
The website seems to imply that these are two separate systems (Intuition-h and Intuition-pv). It’s actually one system with one dashboard, one phone app and one network OWL. The boiler relay is only needed if you don’t have (and don’t want to add) wires from the room stat location to the boiler. It’s not included in the basic Intuition-h price.
The following is about heating controls. Having mentioned the monitor I would simply note that it’s best in class and concentrate on the heating and hot water. There are also some excellent, hidden “geek-mode” features that I discuss below.
Here’s an overall system diagram. It may look complicated but you’ll notice that all the necessary connections are similar to standard thermostats. Just add Ethernet.
The key features for the normal domestic user include:
Heating and hot water are completely programmable so you only produce heat that you need. As energy bills keep increasing the importance of this increases proportionately.
The settings are really easy to control via a simple web interface. This means that you are likely to apply well-thought out settings. This is the opposite of old-style video recorder-style programming.
- The system has a built-in optimiser so you don’t have to guess warm-up times or adjust the settings as the weather changes. You just tell it when you want to use hot water and at what temperature and the system does the rest. Likewise with heating.
Normal user controls use a simple three-button approach, viz. Comfort/ Standby/ Boost. In my opinion this is far superior to a dial marked in degrees of temperature which, although perfect for plumbing geeks, confuses people who just want to quickly over-ride the normal programme. All routine adjustments are made automatically.
All normal end-user controls are available physically, on the phone apps and via the web.
- It’s easy to install and works with almost any boiler. I have a modern condensing one and it’s ideal for that. Unlike some products that require you to run extra wiring this just slots into whatever wiring is already in place. You have a lot of flexibility in where to site the controls.
- The optional energy monitor shows both grid and PV usage and calculates overall cost. You can see the generated energy and what you are selling back to the grid.
Optimisation – how does that work?
As mentioned, the purpose of this is to maintain constant comfort levels without altering the programming as the weather changes.
- The inputs to optimisation are the internal and external temperatures and the house EPC rating. The current version does not know the power of the boiler. In my case I find that my installer underestimated that so I have adjusted accordingly. Occupancy does have an effect too (e.g. teenagers and their friends coming in and out). The system could be adapted to take care of that at some time in the future.
Learning – automatic program adjustment
Although not implemented there is the potential for tuning the programming in response to users’ over-ride actions. For the moment it seems that OWL decided not to do this.
- If there are frequent requests for more heat and/ or hot water the system could adjust the program automatically. This could cause issues between the bill payer and other occupant(s) of course. More importantly, if the European market is mainly people with economy high on their list this could be seen as a reason not to buy. (BTW, The NEST does this but does not seem to be available in a UK-compatible version – I don’t like the temperature-based control anyway).
Additional features for geeks include:
- Graphs that show how the heating system is working. You see the warm-up timing and can spot where your settings are heating air or water more than needed.
Ability to extract detailed data for analysis via downloads or programmatically (via an API that uses UDP multicast). Using this we capture the data in real time and send it to Xively. From this we can visualise it how we like. We are looking at how this could be used for forecasting and boiler diagnosis, adding extra sensors and displaying everything on a single graph.
- Ability to remotely program the system over UDP via an API. We used this in a demo where the room temperature settings are controlled via a google calendar. We hope to get this proven and open-source it.
In general I’m now satisfied that we have the right balance between comfort and economy.
- We have not had any repeat occurrences of the heating coming on in the middle of the night as the programme is much more visible and much easier to adjust. This resulted in significant savings.
- I think there’s room for improvement in the user interface, especially in the program setting but the UI is nevertheless streets ahead of the previous programmer we had. The graphs as they stand do not give geeks everything they need. However, the openness of the interface allow us to graph, analyse and control the system every which way.
- Some aspects of the physical UI (buttons) confused me at first. I would have preferred the 2 functions on the top button for the heating not to be overloaded. Hopefully we’ll get used to this.
- I reckon that some of the wording in the documentation could confuse some people. I can’t see an easy solution to this as it needs to be clear for people in the trade as well as the end-user, geeks or otherwise. “Next comfort period” is an example of this.
- I’m still a little sceptical about the optimisation. This is a proprietary part of the system – fair enough – but I need confidence in its efficacy. I think this will come with time.
I would not be without heating controls of this calibre. The investment was paid back within six months and since then we’ve not only had lower bills but more consistent performance of the overall system.
- Despite my scepticism I am a firm believer in automatic optimisation. However, the jury must remain out on the learning concept that NEST uses. I prefer to make any programme adjustments manually and this the way OWL have decided to go.
- I’m very interested to see what may emerge from the geeky part of the user community given the existence of open interfaces for data extraction and programming. I am planning to open source some of what I’ve done with these interfaces. Meanwhile there is already some code from @aalan on Github. I’ll probably build on this with my stuff.