PSRS Poster

 

The Postgraduate Summer Research Showcase is an event run by the University of Manchester, for postgraduate researchers to produce a poster presentation on an aspect of their Ph.D studies, and present it to a panel of judges and interested members of the student body. I attended last year, and the setup is thus:

The first floor of the Christie Building (this is one of the grand ones behind the arch on Oxford Road) is filled with rows of pin boards, on which over 200 students present their work. Each candidate stays with their poster and answers questions on their work to anyone who asks. There’s a lunch provided for visitors, but you have to register in advance. So no sneaking in for a free butty!

Last year I saw some very diverse and worthwhile topics presented, ranging from understanding the role of various emotions in the progression of anorexia nervosa, to the use of stem cells in treatment for arthritis, to the study of knots in mathematics. The point of the event is that it presents work from all departments, and demonstrates the broad yet deep variety of research being conducted at the University.

First time around I learnt about the research of others, and got to understand the format of the event, and the standard of work expected. Second time, as a presenter, it was part of my journey to become a better science communicator and build up my academic reputation. I submitted a 150-word abstract on the topic of “19th-Century housing in a 21st-Century climate” relating to the particular subject of how Manchester’s vast quantities of Victorian housing could be adapted to suit the predicted changes in climate, and why we might want to do so. I’m not going to publish the abstract here, because I intend to produce more work on it. I don’t want to end up self-plagiarising.

TL;DR version: Manchester has a lot of old houses, many are likely to still exist decades from now, the UK is getting warmer, what are we going to do to make those houses habitable?

I was really excited about taking part, and exploiting one of the few opportunities that I have as a part-time researcher to present my academic work to others. But unfortunately for me, I had a terribly busy few weeks at my day job, and the pressure didn’t allow me time to complete my assignment. Added to this, I got called away to a meeting in London the evening before the deadline, so my plans to do a hatchet job on it the night before weren’t feasible either. I was really disappointed, as this was one of the first big opportunities to experience a conference-like setting, and I had felt so confident about doing it.

I then found out that I had to come in to the office on the day of the presentation to complete an emergency deadline, so the odds were just completely stacked against me.

I will, however, complete the work anyway. I want to study this topic in more depth, and so just doing the poster preparation will form the structure of the report. And so I’ve combined my post about the event with my post about the research. Below is an overview of the areas I want to research in more detail. This is just an outline – I can add so much more to this so I’m not worried about this list of ideas getting into the public domain.

I think the question is a really important one. Manchester has some of the most important architecture from the era of the Industrial Revolution in the whole country. Yes, yes, this is entirely subjective, but the sheer volume of history attached to places is quite incredible. And take a walk through the ghost streets of Ancoats, the former “workshop of the world” – it’s imposing yet eerie. There are many who think this should be preserved and recognised, but there is also a practical reason to retain it – there is a housing shortage and we have an incredible resource ready for exploitation. Just because our buildings are old, it doesn’t mean that they are obsolete. Many of the features of the Victorian home can be used to our advantage.

A great one is thermal mass. Structural materials that hold their heat not only keep the heat in during the colder months, but they retain the “coolth” during the summer. High thermal mass gives the internal temperature a bit of stability – the slow response of the building to the external temperature can help us to control our environment in predictable and less energy-intensive ways.

Related to this is the cavernous basement floors that many larger 19th-Century townhouses have. If you’re going to talk about thermal mass, the ground we walk on is the “go big or go home” option. Below ground, temperatures are very stable. This is why ground-source heat pumps can be used to provide heating in winter and cooling in summer. We know that there will be a small temperature differential between the indoor air and the ground, and we know what it will be. And so we are able to exploit it. So not only could we utilise basement floors to provide cooler and more stable temperature living areas, but we can also use the ground’s own temperature to heat or cool our homes.

Even dwellings without basements very often had ventilated floor voids – providing an essential level of infiltration all year round, and a welcome connection to he cool earth in summer. The latest building regulations have a complicated and fractious relationship with infiltration, with recent drives to insulate and seal our buildings as tightly as possible. This means the old Victorian house often falls short of the standard, and needs to be refurbished and improved prior to let, sale, or use as a working building. But are we showing a lack of foresight? My research aims to cover this topic in depth. Modern houses and apartments already show signs of overheating, before we’re even sure of the full extent of global warming. Refurbished homes have been reported as suffering similar problems, with such a strong emphasis on keeping warm that we seem to forget that summer is even a thing.

Adaptability is key; the ability to stay warm in winter and cool in summer. So undoubtedly airtightness provides close control, but if not applied properly it falls down. This is related to inappropriate use of MVHR (a form of low-energy mechanical ventilation system designed to recuperate waste heat from the air and turn it into useful work) systems (more on this below), which is a real shame because it’s actually a system that could do a lot of good if used correctly.

The principle of MVHR (mechanical ventilation with heat recovery) is to introduce external air to the building, but use waste heat from the indoor environment to maintain an appropriate indoor temperature – if the fresh air is just blasted in, then useful heat will be lost. The MVHR is designed to produce close control of the internal environment, but why does it go wrong? It’s mainly down to poor installation and commissioning of the system, and users not being properly educated about how the system is supposed to operate. MVHR can be used for cooling (as well as heating), by operating in bypass mode.

And there’s more: one of the cheapest and most effective things we can do to an old house is to change the windows. We can use better frames in the existing apertures to reduce leakage and thermal bridging, we can use double or triple glazing to improve U-value (a measure of thermal permeability). Yeah, I know, I went on about airtightness and insulation like they were terrible above, but like I said, it’s about controlling the indoor environment. If you design buildings that are perfect in winter but ovens in summer, that’s not control. Extremely sophisticated glazing systems have been developed to allow light in but to reduce the amount of infra-red radiation getting through – meaning that solar gains can be reduced while still having a light and airy interior.

If you really want to reduce solar gains during the day, you could fit shutters to the exterior of the windows. It might seem odd in 2010s Britain, rather than the Mediterranean or the Southern US, but there will come a time when we need them. It’s also another inexpensive trick that does a lot of good.

And a counter-intuitive thing: You can cool your house more effectively by closing the windows during the day, and opening them at night. Most people’s instinct in hot weather is to open a window, but in the Victorian house, the shade and thermal resilience of the heavy structure actually do more for you with the windows closed. Opening them just moves hot air around. When it’s cooler at night, the interior will be warmer, and so then is the best time to let that heat out.

What else is there about the Victorian home? Oh yeah, chimneys. In many of the converted period homes I’ve been in, the fireplaces have been boarded over. But we can open them up and re-use them – but not for warmth. If the fireplace is covered in winter, than it prevents heat escaping (can you see where this is going?). But open it up to allow summer ventilation, maybe in conjunction with some operable air inlets on the building perimeter, and voila – the stack effect draws air through the building, creating a cooling effect and important levels of air turnover.

That is something that’s often forgotten when thinking about minimising infiltration – that while a reduced ventilation flow can keep the heat in, we also require certain air change rates to maintain decent air quality indoors. No-one likes a stuffy environment, much less one that’s damp, smelly and downright icky.

And now to the roof. There are two different ways of looking at the problem. You can either try to reflect the Sun’s radiation, or absorb it. Well, that sounds like a huge contradiction, but it’s all about manipulation. If you paint your building white, you can reflect the radiation. But paint the roof black (and sacrifice your attic space, sorry), then you can heat the roof void and use it to drag air up through the chimney system more effectively (as discussed above). Cool, huh?

All of the above items are just some of the possible retrofit measures for a Victorian house. My next move is to model these using computer simulations. I’m going to learn how effective each measure will be, under different climate scenarios. But that’s for year two and three of my Ph.D; the end of my first year is about consolidating ideas like the above and demonstrating I’ve understood the appropriate literature.

 

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