Human comfort lies at the heart of our daily lives. The more comfort we attain, the more successful we appear, the more productive we become, and the happier we feel. It’s no surprise that advertisements and major businesses thrive on delivering the next big breakthrough in comfort. We’ll explore the fundamentals of heating, cooling, and everything in between, along with practical strategies for integration into our designs.
Take Virgin Galactic, for example—a company built on creating a comfortable travel experience to the edge of space. I eagerly anticipate the day they unveil their first “edge-of-the-world” hotel. Similarly, stock market trading is driven by confidence: in the economy, a business, or the latest trend. When it comes to our homes, however, comfort and convenience are king.
How do we achieve this? Through confident control. We determine what happens, when it happens, how much it happens, and why it happens. We manage the view, the breeze, the sunlight, the TV, the coffee maker, the stovetop, the temperature, and the environment. The more control we have, the less these things weigh on our minds. Setting them on autopilot, making only minor adjustments when necessary or desired.
Imagine if every aspect of our lives operated with such seamless efficiency—wouldn’t that be the ultimate comfort?
emperature & Humidity
When it comes to comfort, temperature & humidity play a critical path at its core. We are immediately aware that when we are too hot or too cold, our bodies react to extremes in an auto-pilot scenario. If exposed to extreme cold, your body will pump blood away from extremities and closer to organs as primary sources for life. On a day-to-day basis, we seek warm, cool, wet, and dry conditions depending on external forces. When it’s frigid, we seek warmth; when it’s sweltering, we seek cool. When we are drenched, we seek dry; when we are dehydrated, we seek moisture.
Home & Control
The home, especially in recent years, has become a control center for our lives. We operate our lives, careers, family, hobbies, and love from the confines of its walls, floors, rooves, and ceilings. As Architects, we understand the science of how to create controlled environments within a home so that you have control over your comfort. So that, like the body, your home will automatically adjust itself to maintain the health of its vital organs. We employ the latest technological advancements paired with natural passive strategies inherent to our beautiful planet. God is in the details, and those details are felt by everyone, whether done well or poorly, on a large scale and the micro.
Controlling the home’s hot, cold, dry, and wet conditions has many facets. A few big ticket numbers are the different kinds of natural systems available. First, we must heat; our natural sources include fire, the sun, and the earth. We can manufacture heat by burning resources like wood, gas, coal, or oil. We can absorb the suns radiation using materials and technology. Or take advantage of the earth’s consistent ground temperature, energy through the flow of water, as well as atmospheric temperature changes. Once we have a source, we move the heat throughout the space via air, some liquid, or electrical wire.
Cooling
To cool a space, surprisingly, involves the use of heat. In thermodynamics, heat naturally moves from warmer areas to cooler ones. To cool a room, we don’t add cold air; instead, we remove heat. While standing in an air conditioner, freezer, or fridge feels like cold is “added,” the heat is being extracted. Let’s break down how this works.
Basics
Imagine you’re inside a hot room, house, or container, and you want to cool it down. The temperature outside is likely similar or even slightly warmer, but the advantage lies in the controlled environment of the space. Heat transfer makes cooling possible by utilizing coils filled with liquid, positioned both inside and outside the container.
This liquid has properties that allow it to absorb and release energy efficiently. To remove heat, the liquid inside the coil must initially be cooler than the room, enabling it to absorb heat from the air. But here’s where the real “magic”—or rather, science—comes into play. For the absorbed heat to leave the space, the liquid becomes hotter than the outdoor environment.
Application
To achieve this, the liquid is compressed into a smaller space, generating friction and rapidly increasing its temperature. This now-hot liquid is circulated through coils outside the container, where it releases heat into the cooler outdoor air. Once the heat has been released, the liquid must return to the room and cool down dramatically to repeat the cycle. This is accomplished by expanding the liquid through a valve, which rapidly lowers its temperature, to absorb more heat from the room.
What you feel when standing in front of an air conditioner is the fan’s role in expediting this heat transfer. Fans circulate air over the coils both indoors and outdoors, increasing the efficiency of the heat exchange process. And that’s how we cool spaces—by harnessing heat and redirecting it to maintain a comfortable environment.
Heating
The principle of heating and cooling, known as the refrigeration cycle, is the foundation to regulate temperature and maintain comfort in our homes. It serves as the primary method for controlling both heat and coolness. Other systems, while slightly different, employ similar basic strategies to keep us comfortable throughout the seasons.
Basics
In winter, systems like boilers, furnaces, and heat pumps work to provide warmth. Boilers, for instance, heats water using a flame and circulates it through the home via pipes, baseboards, or radiators. This allows heat to transfer into rooms before the water returns to the boiler for reheating. Water heaters stores hot water in a tank, ensuring it’s readily available when needed.
Application
Furnaces, on the other hand, heats air rather than water and distributes it through ductwork. Solar hot water collectors harness the sun’s energy to heat liquid in exterior tubing, which is then used to warm the home. Fireplaces, fueled by wood, coal, pellets, gas, or liquid, heat a thermal mass—commonly brick or stone—which radiates warmth back into the room. Depending on the fireplace design, it may draw air from the room to fuel combustion, which can reduce humidity but provide a powerful heat source.
Geothermal heat pumps offer a particularly efficient solution by utilizing the earth’s stable temperatures. Below a certain depth, the ground maintains a consistent temperature year-round, varying by region. In summer, the system moves a liquid through pipes buried in the earth to transfer heat out of the home. In winter, the same system uses the earth’s warmth to heat the liquid and transfer it back into the house. This approach maintains a comfortable indoor environment and provides a consistent starting temperature for heating or cooling.
An air-source heat pump (mini-split, ductless, or multi-split system) operates similarly to a geothermal heat pump but doesn’t require in-ground piping. It functions like a traditional air conditioner but with the added ability to reverse the flow of liquid to heat the interior space in colder months.
Electric heaters take a different approach by resisting the flow of electricity in their wires to generate heat. While this method can be convenient and easy to install, it’s often less energy-efficient and can pose safety risks if not used properly.
Whether heating or cooling, systems are designed to create a comfortable indoor environment tailored to our needs and leverages a variety of energy sources and techniques.
Everything in Between
Humidity
Now that we’ve explored heating and cooling, let’s dive into the role of humidity—dry and wet conditions and everything in between. Humidity impact on our comfort, is felt on muggy summer days when sweat feels inescapable, or on crisp winter nights when the fireplace leaves us parched. The level of moisture in the air is an essential component of indoor comfort, and air conditioning systems help regulate it.
When an air conditioner removes heat from a room, it also extracts moisture from the air. The heat transfer process causes water vapor to condense on the cold coils, where it collects and is discharged. Think of a can of soda left on a picnic table on a hot summer day. As heat transfers from the air into the cold soda through the aluminum can, condensation forms on the surface. Once the soda reaches the same temperature as the surrounding air, the condensation stops. Similarly, in an air-conditioned space, humidity decreases as long as the cooling process continues.
Our homes, like the soda can, act as containers for this process, but with far thicker walls than aluminum. As heat and moisture travel through walls, floors, ceilings, and roofs, condensation forms—potentially leading to health problems, if not properly managed.
Addressing Moisture
Here’s where the balance gets tricky. Heavy investment in materials and systems to keep external water out of our homes will not remove indoor moisture. The challenge is managing this moisture effectively to prevent issues like mold growth, which often results from improper wall ventilation. Mold thrives in dark, damp conditions, often caused by condensation trapped within walls.
To address this, architects consider the “dew point,” a critical factor in determining where and when condensation will form. By calculating the dew point unique to a location, we can design wall assemblies to prevent condensation from wreaking havoc inside the walls.
In essence, the “in-between”—the management of heat transfer, water vapor, and air leakage—is just as crucial as heating and cooling. Beyond the basic structural elements, a well-designed home must also control moisture, air movement, and temperature changes to ensure long-term comfort, health, and durability. A holistic approach to both the external and internal environment is the key to creating spaces that feel just right, no matter the season.
Air Sealing and Thermal Barrier
Air Sealing
An increasingly standard practice in modern construction, significantly enhances the efficiency of a building by creating a more effective “container.” This is achieved through the addition of an air barrier—a specialized layer designed to prevent both air and water from passing through. Controlling how and where heat enters or exit the home, air barriers maintain a stable indoor environment and improve energy efficiency.
To complement air sealing, a heat recovery ventilation (HRV) unit is often added. An HRV ensures a steady supply of fresh air by exchanging stale indoor air with outdoor air in a controlled manner. The beauty of this system lies in its ability to recapture heat from the outgoing air, using it to preheat the incoming air. This process reduces the workload on heating systems, saves energy, and improves indoor air quality while maintaining a balanced atmosphere.
Thermal Barrier
Another key factor in creating an efficient building envelope is insulation. Insulation is measured by its R-value, or resistance value per inch, which indicates its ability to retain, reflect, or resist heat transfer. The higher the R-value, the more effective the insulation is, which directly reduces the demand on heating and cooling systems.
Vapor barriers, another critical component, repel water while allowing air to pass through. This helps manage moisture within the walls, preventing the growth of mold, algae, and fungi. High-density spray foam insulation is an effective solution, acting as a barrier against air, vapor, and heat transfer simultaneously. Its comprehensive performance makes it a popular choice for achieving a robust and efficient building envelope.
“Envelope” widely used in the industry to describe the system of layers—air barriers, vapor barriers, insulation, and structural materials—that collectively protect the home from external elements. Much like an envelope containing its contents, the continuity of these layers is vital. Proper architectural detailing and precise construction ensure that the envelope remains unbroken and minimizes thermal bridging (areas where materials with lower R-values, such as wood studs, penetrate the insulation).
Thermal bridges create paths for energy loss and undermine the overall performance of the building envelope and reduced efficiency. Focus on a continuous, well-sealed, and properly insulated envelope to optimize control of heat, air, and moisture.
Conclusion
When we collaborate to select systems and design strategies for comfort, we deliver environments with the highest level of control over how and where heat, vapor, and air move through the home. By designing cohesive systems that integrate active technologies with passive strategies (as outlined in my article on energy-efficient homes), we maximize the opportunity to build a harmonious and efficient relationship between you and your living space. A well-thought-out approach ensures your home isn’t just a structure—it’s a comfortable, sustainable environment tailored to your needs.
