Christos’ MSc project is underway, and the temperature, relative humidity, and utility use data is all in – or at least nearly. We’re just waiting on borrowing one data cable to retrieve logs from some of the equipment. We’ve taken new readings from four churches:
City of Edinburgh Methodist Church
Christ Church Morningside
Morningside United Church
Wardie Parish Church
Together with our previous readings from St John’s, and some that St Mary’s Dunblane have very kindly provided to us, it’s shaping up to an interesting set for analysis. If you have been logging temperature and meter readings with an eye to understanding where your gas and electricity goes, we can consider adding your data to the set.
We’ll be using the data to try modelling these buildings in standard software, so that we can try to predict the effects of different kinds of infrastructure changes (insulation, secondary glazing, and the like). One of the things for Christos to think about is where the standard models need improvement to be able to handle this kind of building stock, but we still expect to be able to say something useful from this exercise. We also want to see if we can make sense of how to get the best thermal comfort from the heat that goes in, although we didn’t have time to sample surface temperatures and draught speeds this time around.
In addition, the University of Edinburgh School of Informatics has asked us to put together a shopping list for £2000 of “Internet of Things” equipment – Raspberry Pis, Arduinos, cameras, and the like – that we can use to build environmental monitoring equipment, with the aim of including some of their students in Science of Church. If you wish to be involved in choosing equipment or to host any of these activities, please get in touch.
As part of Science of Church, City of Edinburgh Methodist Church and Christ Church Morningside hope soon to start running a “hackerspace” for church-based projects. They expect to start by designing an electronics project that lets you monitor the temperature and humidity and send the results live to a website or phone or old laptop screen mounted on the wall, but then, they”re up for all kinds of related stuff, as long as it’s interesting, fun, or helps people understand how churches work. We’re already starting to gather people who like science and making things, and to experiment with Raspberry Pis and Arduinos.
As part of the engineering MSc project, we’re just looking at how to get frequent meter readings in a number of Edinburgh churches. This is the set up for one of them: an old Nikon mounted on a window squeegie. A Raspberry Pi is driving it to take time lapse photos every 10 minutes, but we could have used an old laptop. This won’t work everywhere – it requires good clearance around the meter for safety reasons, as gas and electrics don’t mix – but for some churches it’s a cheap and cheerful option. The student will be using the data to understand thermal comfort and heat loss, but it is also useful for getting a sense of what it costs to run the premises under different circumstances.
At my talk for the Church Buildings Renewal Trust Energy conference, I described how hard it is to find good heating controls for spaces that fall in the gap between the markets for domestic and commercial systems, and the difficulty churches have in knowing whether they are being wasteful in running the heating equipment. As part of my talk, I described what I think of as “best common practice” – not what most churches actually do, but what most churches might be able to manage to do cheaply and without major disruption. My “best common practice” consists of logging two things: temperature and meter readings.
There are a few firms that do temperature data loggers, but I’ve seen more Lascar ones than anything else, especially the USB-1 model. The cheapest loggers start at £20. More money gets you a better battery and more data storage so you don’t have to check it so often; a choice of intervals between readings; maybe a relative humidity sensor or an external probe for taking things like pipe temperatures so you can diagnose problems with the system design; and live data readings on the internet. With the USB models, you plug the logger into a computer to get the data. They come with a program that graphs it for you. It needs to go not too near a heat source, and where there’s some airflow but it’s not so visible it will go walk-about – like shoved in the book rack of a central pew.
For meter readings, if there are several people who pass, sometimes a little notebook next to the meter is the best way – it’s pretty easy to snap a picture of the notebook and enter the times and readings in a spreadsheet later. I tend to use a smartphone app (in my case, ECAS for Android) since then I can instantly check whether the energy use seems higher than normal, without any mental maths. It takes a while to get a sense of what normal is, to spot what isn’t! Finding volunteers who pass the meters is often a problem, but it’s so important not to just pay the bills and forget about it that you should think laterally. I know of one church who allows a musician to practice in “off-hours” and has them read the meter (and check the lights are off and the taps aren’t dripping!) in return. It’s much easier to interpret the readings if they’re regular – like after the Sunday service – but any readings are useful.
The reason for logging is this: many of the controls churches use make it very easy for the heating to be on at the wrong times without anyone noticing, just because no one is in the building.
In a house, if you mis-program a heating timeswitch, or accidentally put the heating permanently on, you’re likely to notice pretty quickly. However, in a church, often the first hint of a problem is when an unestimated utility bill arrives. Meanwhile, church boilers are so expensive to run, and the heat leaks out of these buildings so fast, that it’s really worth having enough information to do more than guess about when the heating needs to start and stop under different conditions. Although air temperature isn’t the whole story about comfort, knowing it at least helps. Finally, if you hire space out, even once you understand exactly how to run the heating, having the logger running can be useful. If groups says they were cold, it at least gives you some sense of what their experience was like. A few timeswitch models will do six days of logging for you, for exactly this reason.
We are delighted to announce that we have a new MSc student, Christos Drosakis. He is studying engineering at the University of Edinburgh, and his project is entitled “Retrofitting Edinburgh’s churches and halls for thermal comfort”. As part of his research, we will be recruiting a small number of Edinburgh churches that are willing to have their heating measured. We should have more details for interested churches available in the last week of March.