This post first ran in 2018.
Summer is just around the corner, and while many of us are looking forward to lazy days by the pool with a good book (and lots of sunscreen), we’re also thinking about how we’re going to keep cool without breaking the bank or destroying the earth.
Cooling a mid-century modern home can be particularly tricky. When they were originally built, energy was inexpensive and seemingly inexhaustible, and most areas where they became popular experienced mild summers, so builders and architects put little thought into thermal efficiency.
Single-paned glass walls and tar-and-gravel roofing married to poor insulation can make these otherwise wonderful homes into sweat lodges when the mercury climbs much above 85 degrees.
Fortunately, there’s an array of steps you can take, from major renovation to simple changes, to keep your mid-century modern home livable on sweltering summer days.
Cooling Idea #1: Upgrade Your Windows
The large glass panes that are one of the most attractive features of a mid-century modern are also a major culprit in heat gain and loss.
One of the best upgrades you can make is to replace old single-paned windows with double- or even triple-paned ones, and it’s worth considering when you’re budgeting for major renovation. Unfortunately, the cost of replacing floor-to-ceiling windows can be prohibitive.
A less expensive option is to have a heat-resistant film, often known as low-e film, applied to existing windows using an adhesive backing. It blocks UV rays and can help regulate indoor temperature by preventing heat gain and loss. It’s relatively inexpensive and easy to install.
Cooling Idea # 2: Install Solar Shading
Adding a solar shading system to your home allows you to regulate the amount of sunlight and heat coming into your home.
Solar shading is flexible, allowing you to change the amount of sun your home’s interior gets as your needs change. Systems range from basic shades to high-end motorized automatic systems and come in an array of styles to match your taste.
Cooling Idea # 3: Get a Cooler Roof
If you’re still living with tar-and-gravel or another dark roof, you should definitely consider cooler options when it comes time to re-roof.
Energy.gov notes that a cool roof can be as much as 50 degrees cooler than a conventional dark roof, substantially lowering the temperature inside your home on sunny days.
There’s a variety of roofing options for mid-century moderns, which typically have a low-slope roof; most of these kinds of roofs can be covered with a light-colored coating that will reflect sunlight.
A so-called green roof is another possibility. In a green (or “living”) roof, a layer of planting is laid across an existing roof which is fitted with water-proofing and a drainage system. The plant layer adds insulation from heat, keeping the home’s interior cooler.
Cooling Idea #4: Add a Mini-Split System
Many of us prize the sleek, streamlined look of our mid-century modern homes, and we’re reluctant to add bulky HVAC ducts or window air-conditioning units to them (if we even have traditional windows).
Over the past decade, several companies have brought ductless mini-split air conditioning systems that have long been popular in Asia to the U.S. These systems combine an outdoor condenser/compressor with small indoor air-handling units to cool areas of up to 1,000 square feet.
The conduit pipes are three inches or less in diameter and can be installed through the roof or walls. Condensation can be drained to the outdoors or into the laundry room drain.
Because they are small and can be placed almost anywhere, the indoor units are an unobtrusive and flexible way to cool individual rooms or areas of a home.
Cooling Idea # 5: Add a Solar Chimney
A solar chimney (also called a thermal chimney) is a centuries-old passive heating/cooling system that uses convection to move air through a building, improving ventilation.
A dark-coated chimney is attached to one end of the home (it must be higher than the roof) facing the sun. When sunlight hits the chimney’s dark coating, the air inside it heats up and rises to pass through the chimney’s vent, sucking new air in through a vent located at the opposite side of the home and increasing air circulation. On hot days, opening the chimney vent pulls cool air into the home; on cold ones, closing the vent forces the heated air back into the building.
Solar chimneys are gaining in popularity because of their simplicity, cost-effectiveness and their eco-friendliness: the only energy they require is what is involved in building the chimney.
As always, an architect or contractor specializing in mid-century modern renovation can help you determine the best and most cost-effective ways to keep your home cool this summer.