Thermal Delight in Architecture

There is a slim, well-written book by Lisa Heschong with the name “Thermal Delight in Architecture”, which I have found to be very interesting. Architecture often focuses on the visual experience of a space, but the human body also experiences spaces thermally. Much like our perception of light and space, our perception of thermal qualities is part of the total experience of a building.

Too often our modern buildings try to create a uniform, comfortable temperature throughout, which can be kind of boring in the same way that uniform lighting can be boring. It is also inefficient because different spaces have different thermal needs, much as they have different lighting needs. You will likely want your bathroom warmer after a shower, but perhaps your home exercise space cooler. It also assumes that everyone wants the temperature to be exactly the same, and that is rarely the case. One person might be bundling up while the other is in shorts and a t-shirt.

You may have noticed that the iconic image of a home, as drawn by kids from an early age, usually has a chimney. Of course, prior to modern heating systems most houses did have chimneys. But the image remains because there is something compelling and inviting about having a warm center to the house. Family gathers around a fireplace. Cats lie in a sunny spot. We are all drawn to a spot that is warmer than the surrounding areas. And likewise, in warmer weather, we are drawn to that seat by the open window that captures breezes, or the basement that stays cooler than the rest of the house. It can be rewarding to design and plan for thermal variation in your space. In our home, there is a high-efficiency fireplace where people gather on cool days. And the same space has high ceilings and great natural ventilation so that it is breezy on warm days.

Different materials also can capture and retain heat differently. One major component of a passive solar design is to have a “heat sink” – a material that will store heat and release it slowly. This moderates the temperature, but also provides a warm surface that is pleasant to be near. People often assume that the concrete floor in our addition has radiant heat tubing in it, but it is actually just kept warm by the sun hitting it, and by the fireplace. It increases energy efficiency, but is also pleasantly warm to the feet.