With London having seen a record-breaking summer, it is an excellent reminder for house builders and architects to remember to plan for the extremes.
Yes, summers, where we have many days over 30'C (86'F), are rare; however, we do get them here in London. The discomfort and hassles that this heat causes in properties are easily avoidable with the installation of a few elements.
Firstly, control humidity.
Humidity plays a massive role in the perceived comfort in a home (or any building for that matter) There are dozens of studies into this*. Humidity control also helps significantly with controlling damp, mould and mildew and other issues we deal with throughout the year; it's not just about being comfortable in the heat.
The main benefit of humidity control when we are looking at the hot weather is that cooling systems don't have to run as hard or smaller systems can be installed. To give this some real-world context, if you have ever travelled somewhere really humid, think Southern US swamplands, or Asian Jungles, when it's over 30'C there, you feel sweaty and mucky and not all that comfortable. Compared to the same heat in an arid place like the Arizona desert or the Karoo where 30'C is almost pleasant, you don't feel as mucky or clammy.
The ideal humidity levels depend on the room temperatures, but you should look to keep it between 20% - 40%
Pro tip: if this system can be linked with your HRVF (Heat Recovery and Ventilation & Filtration) system even better.
Now that you have controlled humidity it’s time to look at temperature.
Second, control temperature.
Every new or old habitable home I have been in, in London has always had some form of heating, whether this was wall mounted radiators, underfloor heating or old-style electric space heaters. The one thing you very rarely see (less than 1 in 20 old properties and about 1 in 5 for new builds that I have visited) is Air Conditioning or Comfort Cooling.
Why is this? We rarely need it in the UK. It is a place where costs can be saved bot on the fitting and equipment itself, and a property can be "more efficient" if it doesn't have these systems or is portrayed as not needing them. However, I have not been inside a property this whole summer where there wasn't AC or Cooling where the occupants didn't wish for it.
With how wonderfully thermally efficient our modern buildings are being built these days, many builders and architects will be pleasantly surprised with how small a system can be used to cool a new apartment or home. And these systems have become amazingly efficient.
AC or cooling won't be suitable for every project, true, though I want everyone to at least consider the comfort of their occupants when they are planning their next projects. Retrofitting it is far more complicated and costly. Long-term usability and comfort have incredible value.
I always love looking at how homes can be improved, if you are interested in this discussion, please get in touch.
*Study: Impact of Temperature and Humidity on the Perception of Indoor Air Quality - L. Fang G. Clausen P. O. Fanger - https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1600-0668.1998.t01-2-00003.x
|Outdoor Temperature||Recommended Relative Humidity|
|+20° and above||+68F and above||up to 35% - 40%|
|+10°||+50F||up to 30%|
|0°||32F||up to 25%|
|-10°||14F||up to 20%|
|-20°||-4F||up to 15%|
|Source: Minnesota Department of Public Service|