Wednesday, 13 May 2015

Low-tech problems with high-tech buildings

New buildings often use more energy than they are supposed to, and quite often the reasons are the same as in old buildings, easily identified and fairly easily to fix. I went to a talk yesterday about one example case which was a prestigious university arts faculty building. I like to think that if the occupiers had been engineers these problems would have been sorted more quickly but I could be wrong. In this instance, as in many others, you didn't need high tech equipment to track down a good deal of the energy wastage.

Radiator pipes not insulated means some rooms were too hot and some too cold.
Firstly, some of the rooms were too hot and some were too cold. It transpired this was mainly because the radiator heating circuit pipes were not properly insulated. The first rooms on the circuit were heated by the pipes as well as the radiators. If you are too hot you can adjust the valves on the radiators but not the pipes. The rooms later on the circuit didn't get much heat at all because the water pipes had already got cold.

I have met exactly this problem before and it is easy enough to diagnose - you can see that the pipes are not insulated and you can feel the temperature in the pipes by touching them. (Be careful though as they can be hot enough to burn.) Sometimes the problem is 'fixed' by increasing the temperature of the heating circuit so there is at least some heat left in for the colder rooms. However this increases the energy bill and it means the hot rooms get even hotter. The proper fix is to insulate the pipes.

Also, it is likely that the radiator circuit had not been balanced properly. The building was commissioned in a fearful hurry because construction overran leaving little time before the date of first occupation. This is of course the rule rather than the exception.

Automatic window openers were stuck open.
The building was mostly ventilated by automatic louvres and window openers. Unfortunately, some of these had got stuck. It is easy enough to see when the windows are open on a cold day. Then it is up to maintenance to fix the problem.

Ventilation and heating systems were working against each other.
The ventilation system and the heating systems were not integrated and were often working against each other. This is easy to identify because you can look and feel to check if the ventilation is active and the heating is on. Unfortunately it can be a bit harder to fix, depending on the control systems.

Lights were on all the time because no-one knew how to turn them off.
The lighting in communal areas and corridors had a single point of control in the reception area. Needless to say, this was not just a simple switch - in fact you had to enter a password to access the control. Unfortunately, the one person who had been trained to operate this and knew the password moved on to another post taking this knowledge with them. Fortunately - or perhaps again unfortunately - the lights were always on rather than always off. The result was that half the electricity consumption in the building was for lighting, even though it had been designed to make use of natural daylight most of the time. This is very easy to diagnose just by popping in overnight to check what systems are on. It is also quite easy to fix, in this case by getting the password reset. Though it would be even better to install distributed controls so that they could be switched off in different areas when not needed.

There were some other problems with this building that were 'designed in', mainly to do with air leakage and circulation. However, the ones I have described were responsible for a large part of the energy wastage.

Sadly these problems are not unusual.
I am reminded of an older office building that I have reported on before (see Energy Saving in a Rented Office). It also had uninsulated radiator pipes and stuck window openers. It also had ventilation systems working against the heating system - people opened the windows because they could not turn off the heating. Also, no-one in the building knew how to adjust the heating system and in that case it was the heating, not the lighting, that was left on all night.

Doing an energy audit isn't rocket science.
All it takes to diagnose these kinds of problems is a simple walk though energy audit. Go into each room. Ask the occupants if they are comfortable and how they manage their environment. Check the windows close properly and that the radiators are evenly warm. Check the pipes are insulated! (This is much more fun with a thermal camera but you don't really need one.) Check what systems are on that don't need to be, and ask whose responsibility it is to turn them off. Do this several times - on a cold day when the heating is on, and on a cold day when it isn't, and out of hours, both at weekends and overnight.

This is so easy that children can do it. There are lots of resources to guide teachers to get their pupils involved like this one from the US EPA. Also the Centre for Sustainable Energy has a more comprehensive checklist for community buildings that can be adapted for pretty much anywhere. Even without a walkthrough, looking at energy use data can highlight problems (see Potential Energy Saving in Schools).

In my experience, however, identifying the problems is the easy bit. Getting them fixed means finding the right people and persuading them to sort them out. That can be another game entirely.

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