Month: November 2017

How much data is your building generating? Are you getting any value from it?

Even if you are not operating state of the art smart buildings with nearly 30,000 sensors, the chances are that you will soon be swimming in data. Industry estimates suggest that we’re well past 500 million end points from commercial buildings, and heading towards 3.5 billion in the next three years (thanks, Gartner). That’s end points…each one delivering a data stream at rates potentially of many times a minute.

Its a crazy amount of data, and it won’t be tractable without some deep thinking on applications and analytics. If properly harnessed it offers huge scope to improve the efficiency of buildings and their capacity to deliver comfort and improve productivity for the people working in them. For that to happen, though, building operators need to get a bit cleverer about their data and clearer about what their data strategy needs to be.

Where to start with data in your building

A good data strategy will clarify the value of the data being collected and ensure it is fit for purpose – sadly not the case in so many buildings right now. A simple example – consider the difference between a supply air temperature sensor 3M up in an office ceiling and a desk level comfort sensor. This difference is not just location, but also the rate of update and data availability for analysing previous periods. Lower data rates may be good for control applications, but there are certain applications that are only possible with higher data rates.

So data strategy should help flush out what you want from your data, which drives some important decisions about what, where and how frequently to measure.

The best – and simplest – first step is to assess what your goals are for data. What are the really valuable applications? For most commercial buildings the two major categories of time related data – metering data and building management systems – have obvious lead applications – settling energy bills and controlling building services, but they typically need some enhancement to be able to support detailed building analytics.

Data goals for buildings

I’ve been around in the smart building market for some years, and as it overlaps with green building objectives a number of clear applications are beginning to emerge that support the efficiency of buildings and the comfort of occupiers: 

• Optimise energy performance – Match energy usage to the buildings activity
• Additional (retro) commissioning – Providing a regular review of the buildings systems to check they are working as they should
• Measurement and verification – Demonstrating that improvements are performing as anticipated
• CO2 reporting – For external and internal communications
• Permanent environmental monitoring – Ensuring energy efficiency does not compromise building’s delivery of comfort. Identifying wasted space and opportunities for supporting improved productivity
• System innovation in design – Identifying new opportunities for energy savings and improved productivity by making major changes to environment.

From green to brown – how value of data can trickle down

The evidence is that these applications add real value to buildings – green buildings are typically 25 – 35% lower to operate and occupiers report 4% more productivity from staff. Excitingly, it seems there is potential to apply some of these to buildings that haven’t originally been conceived as green or smart, to improve them.

As a quick, scaleable win for occupiers and operators of commercial, data has huge potential, if it is structured correctly. Purrmetrix can help fill in gaps and support your analytics – if you want to know more, do get in touch.

How easy is it to fool a movement sensor?

I can’t be the only person who has been working late at night in an office when suddenly I am left sitting in darkness, because the PIRs (passive infrared) movement sensor that controls the lighting has decided I’m too still.

In fact I know I’m not the only person, because an FAQ from customers who want to use our new movement sensors for measuring office space usage is how sensitive they are. And so we decided to do a little experiment in our office with two sensors, some software engineers and a very bouncy visitor.

We wanted to look at a range of activity levels and locations for sensors, including

• distinguishing between one very active person (moving furniture around), several people talking and interacting and the classic ‘stationary deep thought’ pose beloved of software engineers
• looking at the effect of location, in particular the difference between ceiling and wall mounted sensors. The ceiling mounted sensor was 2.7m off the ground in the middle of the workspace, and the wall mounted sensor was 1.5m off the ground on a column in a direction that covered half the office space.

Over a week, we found the ceiling sensor accurately reported all presence in the office. It is difficult to distinguish short, vigorous bursts of activity from one person – they look very like a few people interacting – but they did typically tend to be shorter in duration.

Meanwhile the wall mounted sensor did exactly what was expected and recorded all activity in the half of the office it could see. In the analysis below it is the light green trace:

Most usefully, our tests reveal it’s very unusual for anyone working at a desk to go for many minutes without some small adjustments of their body or working environment. Perhaps reaching for a pen, scratching your nose, or moving a mouse. It’s perfectly possible for someone who is focussed on their work (take a bow my software colleagues) to record no movement for a minute or more but if data is aggregated in 5 minute or larger buckets then we had a close fit between occupancy and movement.

To avoid over sensitivity, our movement sensors work with a target concept that is about the size of a human limb, so, if you are in Tom Cruise mode the best way not to trigger the sensor may be to practise moving one finger at a time at less than 1 m/minute. You might not get any work done, but that’s OK…no one will know you’re at work.

If you want a slightly more technical explanation of the sensitivity and range of our movement sensors you can find the data sheet here.