Changes to the Purrmetrix webservice

It’s been quite a year.

Every bit of our service has expanded: customer numbers, project numbers, number of buildings, analyses and hardware served. Thank you to everyone who has used the service and given us very useful feedback.

Based on that feedback, it’s time to make some changes to the webservice. Our aim here is to make it more intuitive and to add some extra features.

The changes will go live over the next couple of weeks, so let’s take a little tour:

1.Webservice layout

The most obvious difference is that we have moved the projects menu and the views menu up into the top bar. This frees up the full screen width for visualisations and analytics. To switch between projects or to add a project you now need to click on the drop down menu in the top bar.

Can’t see what you are looking for? The drop down menus support scrolling.

Webservice temperature analytics

You’ll still be able to name the project and set it up in the project dialogue box (which you enter by clicking on the title of the project).

Similarly, if you want to set up a new analytics view, you click on the drop down menu and select the view you need. It will open in the main screen and you can add your kittens from your libary (the section with ‘Your Things’ at the top) or from other views.

Temperature analytics webservice

2. Checking (and removing) kittens

As before, if you have a kitten in your hand and want to know which one it is, you can squeeze its face and the kitten in the webservice will turn red:

Temperature analytics webservice

BONUS TIP – for power users if you activate the magnet at the top right hand corner of each view, every time you squeeze a kitten it will add itself to the view.

Removing a kitten from a view is also simplified – when you pick up a kitten from within any view, a trash can will appear in the bottom right of your screen. You can drop kittens in them and they will disappear from the view you had selected them from. Note they will stay in all other views in the project, UNLESS you take them out of the project library view (at the top) and trash them. This will cause that kitten to disappear from all views in the project.

3. Scrolling through graphs

As well as making graphs much quicker to deliver information, we have activated a click and drag zoom to help zoom in and out on graph data. Here’s how it works: you place your mouse in the middle of a graph, click and drag either backwards (left) to zoom out, or forwards – right – to zoom in. The longer you drag for, the bigger your zoom.

Temperature analytics webservice

4. Mean/max/min for graph views

For graph views, we have added ‘summary’: the ability to track the mean, max and minimum of any group of kittens over time. The feature can be turned on in the view dialogue box, which you get to by clicking on the view title.

Temperature analytics web service

Selecting ‘mean’ here produces this:

Temperature analytics web service

Helpful if you need to find out what the average performance across a zone is or track the impact of an improvement that affects many areas.

5. Project addressing

Projects and teams can both now hold address information. In future, this will allow your projects to be mapped in Google maps and potentially integrated with other localised information.

6. What’s next?

We will push these changes live in the next two weeks and look forward to your thoughts. And if you’d like to report problems or suggest improvements to performance, please do get in touch. We love to hear from you.




Working out the numbers – how many sensors do you need?

Often, when we’re talking to customers they will ask us how many sensors they might need. This is a great question because it lets us talk a bit about the applications customers are using the sensors for.

Honestly, we don’t have all the answers on this because we’re still breaking new ground here. There are a lot of potential applications for Purrmetrix that haven’t been tested thoroughly. That said I thought it might be helpful to explain a few rules of thumb we tend to use in answering this question.

TL:DR – it depends upon what you want to achieve with your project. Contact us if you want to talk through the specifics of what you are measuring

How specific is your HVAC analytics project?

Many customers start working with us in exploration mode. They want to identify and pick apart all the problems in their estate. In that case we suggest a fairly high density to start with – a sensor every 10 sq m or one for every cluster of desks. So in a fairly average 60 person office we’d be thinking about 15 – 20 sensors.

In a case where you want to collect data around a known problem, it’s generally possible to be a bit more precise about the numbers, depending on the type of problem you’re looking at.

What sort of problem are you hoping to test?

If you are looking at problems with specific parts of your building services – for example in each fan coil unit – then you have a fairly obvious guide of one or two per FCU. Although kittens can be redeployed its always better in our experience to test all parts of the system simultaneously so allow enough numbers to do that.

On the other hand, you may be interested in how the building’s fabric is performing – how quickly certain parts of the building heat and cool compared with outside temperature. If you think you have generalised insulation problems then 3 or 4 sensors along each aspect can generate quite a lot of information on the rate of heat loss, although you should allow for more if the materials change significantly along each aspect.

Are you analysing or influencing?

If you are hoping to influence behaviour (whether to save energy or helpdesk time) then you need to be presenting data at the hyperlocal level for each person. The ideal extreme would be one for every desk or working area, but in practise we find that a sensor within the same 10 sq m is generally adequate. Remember they can always be moved to accommodate sceptics!

How are you displaying it?

Because monitors are limited in how many pixels they can display the webservice has limitations in the way it displays the image of your building/project, which will be sized to 600 px wide. This generally means it is tricky to display very large areas with a lot of kittens, or make very precise placement of kittens on a low scale (zoomed out) plan.

Screen Shot 2016-10-23 at 20.55.14

At this scale it can be tricky to position this number of sensors correctly.

If you do have a project requiring a high density of sensors then make sure you zoom in and use the largest scale plan you have.

How the temperature gradients work

The colour gradient between kittens is not a reflection of the actual temperature in the gradient but of the confidence that it reflects the correct temperature. We don’t vary the size of kitten icon or the spread of the colour gradient so its spread is determined by the scale of the plan or image you upload the kittens above appear to be covering a floor area of around 6 sq m.

You can make the kittens disappear from the plan to better understand what is going on. Do this by clicking the arrow to the left of the view titla:

Temperature map of office

In general we don’t recommend uploading plans of any building of more than 60 meters.

In summary

  1. You don’t have to get it right first time, because you can redeploy your sensors
  2. Size your order to your use – general exploration and influencing behaviour will take more kittens
  3. Don’t try and display too many kittens in one heatmap view. Use other views (graphing) for that.
  4. Talk to us if you have a problem building and you’re not sure what the right level of diagnostics might be.

Is there more to proptech than cleantech?

A recent survey from the RICS found that interest in proptech is reaching a high, with 79% of those surveyed saying their companies are planning to increase investment in technology.

Consensus in the profession seems to be that we’re only scratching the surface with what technology can do:

Cleantech and energy efficient buildings present one business case, but there is a lot of interest in what better workplaces can do to improve productivity.

Anyone with views on that relationship might want to get involved in the Stoddart Review, which promises to put the workplace on the corporate agenda – and provide a lot of data on what technology should be doing for the built environment.

Using onboard monitoring? Here’s four things you’re missing.

IMG_3382If your server, rack or cage is in one of the UK’s established and well run data centres you can probably guarantee that they are going to keep the temperature within a fairly well controlled temperature range (unless something goes very wrong).

You also probably already have onboard temperature monitoring in your servers, disk arrays and switches so I bet you have never thought about any other type of temperature sensing or even mapping.

But if you’re simply looking at onboard data the chances are you are actually missing out on a lot of interesting, actionable information. Lets talk about the useful stuff that we at Purrmetrix can help you learn.

1. Locating a Hot Spot.

When you look at your onboard monitors you get a number on a screen – maybe even a graph. But how – and where – does that fit in to the bigger picture and I mean that literally. By putting data into a heat map you can see instantly how that all fits in. Is the machine you are looking at the actual problem? Is it a wider issue in the rack with air flow? Is it one of the machines next to it? A picture paints a thousand words after all. You could use this information to help you to make a better informed choice about where to fit your next piece of kit or how to set up the next rack you buy. Untitled 2 (1)

2. Tracking access to racks

If you have 3rd party engineers accessing your kit for maintenance, replacing kit or just remote hands from the DC to check something out for you wouldn’t you like to know bit more about what they are up to? When they opened the door, which racks they accessed, how long they left the door open for while they walked away from the DC floor or even if they left the doors open when they left. Yes the data that you get from the kittens really are that sensitive as the picture below shows.Screen Shot 2016-07-12 at 10.29.24

3. Remedying problem rack conditions

So what can you tell from the kittens that we believe can help you find out a bit more about whats going on when a fault occurs: if the temperature of the air coming into the rack has risen, if the air flow is being obstructed, someone has been into your rack, the humidity (only with the temperature and humidity monitors) has got up which could suggest a leak or a liquid spill, heat from a next door rack is effecting your rack etc. You could set up alerting in your account so that you can be informed when things go out of your preferred parameters.

4. Analysing what went wrong

Lets say that you had a total network meltdown and you really didn’t have time to study exactly what was going on in your rack regarding temperature. That’s ok because you can go back and replay the data when you have the chance. You might not have been able to figure out what happened or why. Perhaps the same scenario keep cropping up and causing a disk to fail or kit a server to reboot. You could find that there is some small event that is causing the issue or even that now you know how it shows up on the data you could recognise it sooner, set up an alert and stop it from causing the issue before it starts.

The importance of time and space.

There are a lot of possibilities but only with the correct level of monitoring. To make sense of the data you need to have information on where it is coming from, as well as when, and you can’t get this just from your onboard sensing. It’s time to bring our thinking up to date.

kitIf you think all of this sounds interesting then ordering a starter kit would be great place to start. A medium bundle contains 1 gateway and 8 kittens, this would do the trick for one rack with 4 in the front and 4 in the back spaced equally from top to bottom. If you want to have a chat to us about your current step up, problems you think you may have and how best you can detect them using kittens then you can contact us on 01223 967301 or

Liz Fletcher is Purrmetrix’s project manager. After nearly a decade in IT, miles of cabling and gallons of tea she is currently dividing her time between Purrmetrix and the UKNOF Programme Committee.





When Cleantech met Proptech – The Cleantech Futures Conference

Believe you me, startups in clean tech and property can end up going to a lot of networking events. Experience has taught me that a small conference that tries to cover a lot of ground risks leaving its audience behind – ‘stretching’ the schedule can leave delegates listening to topics that don’t engage them. Cambridge Cleantech’s agenda for their 2016 event was ambitious, covering clean tech growth, ideas and innovation for Connected Cities, presented by 26 speakers in a single day.

So I was sceptical. And I was proved wrong.

This was a conference with a lot to say and a lot to do, and if the objective was to arm us with facts about smart cities and innovation, it certainly succeeded. A random selection of fun facts:

– The UK’s emissions have fallen by 36% since 1990, according to the Committee for Climate change. Following the policy pathway fixed for the next 7 years should see the reduction increase to 57% down.

– In the UK water industry 24% of water supplied is still lost through leakage. That’s 24% of pumping energy wasted

– In terms of the ratio of broadband speed to broadband cost, large Asian conurbations like Mumbai are streets ahead of European capitals.

Unexpected heroes – the real estate industry.

Unexpectedly however a common story came across from a number of different speakers. A story about the real estate industry, community and sustainability. Historically, real estate (I include developers, landlords and their advisors in this group) haven’t treated sustainability as a priority. This is now beginning to change, at first at the top end of the commercial markets, where Colin Lizieri from the Land Economy department at Cambridge showed us how green premiums and the poor risk profile of less efficient buildings was beginning to influence valuations for property portfolios.

Slides on sustainability and real estate

The real estate industry: 40% of the world’s energy use and 40% of the enthusiasm needed to do anything about it. Slide from Colin Lizieri, Department of Land Economy, Cambridge University

Coming in the other direction, Savills latest research (presented by Nicky Wightman and available online with a fun interactive model) on the most attractive cities to operate tech companies in emphasised the importance of quality of life in cities, and how efficiently they work. Remember, the value of any individual building is limited by how attractive it’s city is – by its context and the community which it sits in.

From building to city to community

And here’s the interesting part…what happens when developers start to think about not just individual buildings but how they work together to create effective cities, and even effective communities? A couple of great examples came from Rebecca Britton at Urban & Civic, developers of two substantial sites in Cambridgeshire (Alconbury and Waterbeach Barracks). Urban & Civic are spending a lot of time working with the existing communities around their developments to make sure that these developments enhance their lives and are sustainable.

These sorts of brownfield developments are small scale templates of how to integrate smart city solutions – for transport, sustainability, quality of life – and offer some useful lessons for anyone interested in larger smart city innovations and how they might get adopted. Particularly in how to work with the public to make sure existing communities feel a sense of ownership and interest in these solutions. Craig Bennett, CEO of Friends of the Earth  made this point in his opening – smart city solutions need to be adopted from the grass roots up, and as with low carbon generation technologies, the most effective way to engage people is not to thrust top down solutions on them but to give them ownership of the technologies.

Smart city technologies

And yes, there was a lot of technology at this conference. It’s a smart cities conference in Cambridge, what did you expect? From a new marketplace in energy proposed by Origami Energy, to hyperlocal weather forecasts for bike commuters, there is a huge range of solutions just waiting for markets to mature and business cases to be made. This has been the case for many years in smart cities and while government initiatives in many countries have supported pilots there has always been a sense that wider adoption is just around the next corner.

Yesterday was the first time that I genuinely felt the industry might be turning the corner. A Real Estate industry which learns to build efficient high quality places, not just buildings, and is rewarded for doing so by a community that gets returns from these better cities – that’s a welcome step up from our current situation.

We’re looking forward to doing business with them.

Beer Festival Calibration

Here at Purr Towers we all like beer and we all like small accurate internet connected temperature sensors. So we thought why don’t we bring the two together? This weeks 43rd Cambridge Beer Festival seemed like the perfect opportunity, so as the latest in a long line of Cambridge technological firsts Purrmetrix are pleased to bring you the first internet of things enabled beer festival. Welcome to the future.

What’s Purr?

Purrmetrix build small retrofit-able wireless battery temperature sensors that report their temperature every 17 seconds or so via a 433MHz radio through a gateway and then onto our database. We also provide software that allows our customers to browse, graph and consume their data and run various kinds of analytics and to set alerts. So we had a chat with the organisers of the beer festival to ask them what might be useful and we quickly settled on a plan.

Deploying kittens to keep watch over the beer

We call our temperature sensors kittens. We deployed 26 kittens in total. 11 kittens are measuring the ambient temperature in the main marquee. These are spread around the front of the various bars. If you look carefully on the posts at just above head height you might catch site of our smiley faced kittens blinking away, they flash every time they report there temperature.

A bundle of temperature monitoring kittens

A bundle of kittens ready to go and monitor beer temperature

We also placed 9 kittens in the ‘Igloo’ which is a chilled cellar like room where the Key Keg beer and some of the other craft beers are stored. And we also chose 6 beers where we placed two kittens on the back of each cask. Disclaimer: the kittens on the beer are measuring the ambient temperature of the air around them, which will be a little warmer than the temperature of the beer. But the beer is actively cooled, by chilled water pumped over the casks and the casks and the kittens are well insulated. The fact that the temperature these kittens are reporting is very stable tells me the system is in a nice steady state so using this data as a proxy for the beer temperature is not a totally stupid thing to do. But can we do better?

Tim’s grim experiment

Of course we can. When I go to the festival this evening I will be taking a modified kitten that has been sheathed in a prophylactic, which I will be using to measure the temperature of these beers as they will be served to the punters. This will allow us to added a small correction to calibrate our kittens.  I need to make clear it will only be my beer the device will be dipped in*  I will report back on how this goes tomorrow. Anyway pop to the earlier blogpost to get the low down to look at the data that we are collecting and feel free to email us or tweet if you want to know more.

*That’s a relief. Ed.

Too hot/too cold – what can you do next?

Create your own user feedback survey

Thermostat wars – what if they’re not all in your head?

So we’re coming into the office air conditioning season after a warm dry spring. And that means it’s time for the annual crop of headlines about thermostat wars. Like this one, and this one and this one. Notice something similar with these?

That’s right – all of the ‘discussion’ about office temperature seems to be about the difference between people. Specifically, that men generally like it colder than women. Oh, and for some strange reason the ladies in marketing always feature as needing it hotter than anyone else.

Folks, I smell a giant, slightly sweaty, rat here. Of course, there are differences in how people perceive temperature. However, if you’ve had the pleasure of ploughing through the ASHRAE and CIBSE literature on temperature and comfort in offices, then you know that an immense amount of research effort goes into identifying a range of temperatures that works for the largest number of people.

So when you get surveys that suggest 60% of people are unhappy with the temperature in their office – cooling in summer or heating in winter – my conclusion has to be that its much more likely the problem is the HVAC.

Too hot and too cold. In the same office?

People disagreeing about office temperature and fighting over the thermostat makes good headlines. Truth is, they may both be right. Its completely normal for office temperatures to vary across the room. So Karen sitting under an air conditioning vent may well be freezing while Mick starts to sweat in the sun at the other side of the room.

And while humans aren’t very good at estimating absolute temperature, we have quite high levels of sensitivity to changes in temperature – anything over 1 degree in 15 minutes is generally detectable. So even quite small variations throughout the day tend to get noticed, particularly if they coincide with peaks and troughs in metabolism.

Why does my office temperature vary so much?

Temperature – and how it affects comfort – is a more complicated subject than it might first appear. If we break it down to its component parts it begins to be obvious why variations happen in buildings.

Perfect office temperature

Perfect office temperature – they don’t seem worried by convection

The basic physics of how heat moves around is probably familiar. Heat can be transferred from one thing to another by radiation (heat energy being transferred directly – like in sunlight), convection (heat being carried around in air or other fluid) or by conduction (transfer along a physical object like a metal spoon in coffee). In an office, radiant heat and convection are normally the two most significant mechanisms for transferring heat around, and these create the first set of challenges.

Because heat will move around a bit differently, depending on the mechanism. Unless you’re sitting in an office made of warm water convection is going to rely on warm air circulating around your office. On the other hand, any ‘body’ – a window, a wall, a desk, a laptop – that you can see will be radiating heat directly at you. If they are at a similar temperature to you this effect will be small, but once the mean radiant temperature gets more than 5 degrees out of whack to air temperature, you are likely to feel uncomfortable.

Since the biggest ‘bodies’ in any office are generally windows and walls, and since they are generally exposed to external temperature, being close to a hot window or a poorly insulated wall makes you very vulnerable to fluctuations in their temperature. And you might be freezing while Frank near the kitchen is toasty.

But wait, there’s more! Why your office’s temperature varies over time.

Do you like graphs? Of course you do. Here’s a fun one:

Measured temperatures in open plan office

Office temperatures Cambridge 7th – 27th April.

This is a graph of the temperature measured at multiple points across an open plan office for 19 days. Spot the two weekend periods (here’s a clue – look at the minimum temperatures). Why are they significantly cooler? It’s not just because there is no heating on. In fact the main difference is the lack of people. Occupation adds heat. A lot of heat. Each person gives out about the same about of heat as a 100 Watt lightbulb, and that’s before you add in the lighting and equipment that they need.

On top of that, there are long term trends that change how hot offices get, from cooler technology – computer monitors that use LED screens – to hot desking. So over the course of the day and over time you can expect to see the heat load (how much heat is generated) change a lot.

Surely my office heating and ventilation is designed to deal with all this?

Indeed it is. And in future blog posts we’ll have a look at some of the work on how zoning, building management systems and natural ventilation is helping.

However, as you can see, how comfortable you are during the working day is actually the sum of some complicated factors, and that’s before we get into activity levels, clothing, humidity, air speed and all the other issues that have significant impact on the working environment. A good building should compensate for many of these, but there are multiple reasons why they change over time, so regular reviews of whether the building’s heating and cooling is doing its job is always a good policy.

Not just telling the lady in marketing to put on another coat.

This is just the first in what we hope will be a series of posts about HVAC and comfortable buildings. Tell us what problems you’re having and we’ll make sure we cover them.