How Do Passive Heating and Cooling Work?
Many of our clients building custom homes on the Wasatch Back are interested in building and living in passive homes. Passive design has been around for a long time, and is experiencing a resurgence among architects, builders, and homeowners alike. This design concept is rooted in taking advantage of nature’s ability to heat and cool without relying on mechanical systems as the primary source of temperature control. In this part of the world, well designed passive homes are appreciated in their cost saving ability and in their positive net zero energy environmental impact.
If you are looking to build a new residence or vacation home in the Park City area, a passive design strategy is something to strongly consider. Some of the most beautiful homes in our area are passive homes, and are a more environmentally friendly and sustainable option to alternatives.
TWO WAYS TO HEAT + COOL
Most of what goes into the passive design relates to heating and cooling. In architectural design, there are two ways to heat and cool: mechanically and naturally. Passive homes rely on natural heating and cooling as much as possible. This is not to say there is no room for mechanical systems in passive homes but, rather, to say the need for these systems are minimized as much as possible.
A mechanically heated and cooled home requires a standard HVAC system. A forced air, radiator, or radiant floor system keeps the home warm in the winter while air-conditioning keeps it cool in the summer. In both cases, a significant amount of energy is dedicated to climate control. A passive home is designed to work in harmony with the natural surroundings, thereby mitigating the need for mechanical systems. Architects specializing in passive homes prioritize things such as lot location, tree cover, and orientation in terms of siting and then a well-designed building envelope in the design of a passive house.
UTILIZING THE SUN
From late fall through early spring, a passive home heavily relies on the sun, and uses it to the home’s advantage. The sun becomes the most important heating element. From late spring to early fall however, it is just the opposite. A passive home stays cooler by limiting how much sun penetrates interior spaces.
The angle of the sun is one of the primary considerations when designing a passive home. It shines overhead at the peak of summer but hangs very low in the winter. Passive homes can be designed to block summer sunlight but welcomes in the winter sun. Here are just a few examples of how it works:
Trees – Building a passive home with strategically placed trees surrounding it can reduce its exposure to summer sun. When fall and winter arrives, the leaves fall away and the home is warmed by the winter sun.
Overhangs – Well-designed overhangs adequately block the summer sun when it's overhead, but when the sun sinks lower in the sky, overhangs do not interfere with its ability to warm through the windows. Our digital models calculate the ideal overhang dimensions for each home design.
Insulation – Proper insulation keeps heat in during the winter but out during the summer. No home can be truly passive without suitable insulation and a well-designed tight building envelope.
While the sun is the focal point of passive design, residential architects consider many other elements when designing a passive home, working with experienced architects with a background in sustainability is an important aspect when it comes to designing your passive home.
BENEFITS OF GOING PASSIVE
The benefits of passive design don't stop at energy savings and increased comfort. If you are ready to learn how passive design can make your Park City dream home even better, feel free to reach out to our architects at Sparano + Mooney.
Our passive homes are found throughout the Wasatch Back and throughout the rest of Utah. As experts in passive design, and we would be excited to incorporate this expertise into the design of your new vacation home or mountain residence.