In 1998, one of America's most beloved historic homes got an HVAC upgrade. After existing for more than two centuries without central air conditioning, George Washington's Mount Vernon received a state-of-the-art air cooling system.

A number of people voiced objections to the installation, saying it would damage this national historical site unnecessarily. But in the end, the group that manages Mount Vernon decided that an air conditioning system would have enough benefits to make the upgrade worth it, including the chance to make tours of the home more comfortable for the over one million annual visitors. The project managers also took care to integrate the system as seamlessly and harmlessly as possible.

No matter how you feel about the air conditioner at Mount Vernon, you may wonder how its early inhabitants stayed cool during Virginia's hot, humid summers. The answer lies in many architectural features of the house, elements that are common in countless homes built before central air conditioning became possible.

Older Home Features That Enable Cooler Living

How did architects and builders create comfort without ducted HVAC systems or even electricity-powered fans? They included key features like those listed in this section.

High Ceilings

We've all heard that hot air rises. If a room has higher ceilings, the warmest air can rise to the top, making the lower parts of the room where people live cooler and comfier. Mount Vernon offers an example of this accommodation: the average ceiling height on Mount Vernon's first floor is 10 feet, 9 inches. Also, the largest room on that floor, the New Room, has ceilings that reach 16 feet, 6 inches high.

Windows or Doors

Even on the hottest days, a breeze often blows by, so many historic homes incorporated well-placed windows that allowed that moving air to come inside. Moving air provides a better cooling effect when it can follow an air stream and keep moving. To enable this cross ventilation, people would open two windows that line up with each other.

Mount Vernon's New Room has two doors that sit on opposite walls to create cross ventilation possibilities. The Washingtons used this room to receive guests and entertain, so it makes sense that its design enables it to stay as cool as possible. Many older homes in warmer regions of the US also incorporated windows and doors that allowed residents to enjoy the occasional breeze.

Covered Porches

Before the rise of A/C, the indoor areas of a house often felt warmer than the places just outside. People would often seek a few degrees of comfort by sitting on porches. Large eaves over the porch and trees planted nearby provided shade for several hours every day.

Mount Vernon features a famous, two-stories-high porch, often referred to as the piazza. This porch has eight regal columns along its length. Many homes built between the early 1800s and the end of the post-World War II housing imitated this grand element in some way so the dwellers could seek respite from heat.

New Air Conditioning Possibilities That Preserve Older Houses

Even though architects of historic residences installed these clever features so people could stay cool without air conditioning, most people today prefer to live with electricity-powered cooling systems. Luckily, homeowners can work with HVAC professionals to ensure their homes have these desired upgrades without compromising the original elements.

For example, many people who own older homes choose to install ductless mini-split air conditioning systems. These units can deliver cool air throughout a house but don't require the installation of ductwork. Installers often have to lower ceilings or cut into original home parts to make room for ducts, making ductless units more desirable.

If an older home features lots of original wood work (such as molding, doors, or stair rails), humidity control also matters. Cool, water-saturated air can cause condensation, and over time those water droplets can seep into and warp wood. Humidity can be controlled and reduced with features like dual compressors, which are common in units with high energy-efficiency ratings.

Are you curious what type of air conditioning they installed at Mount Vernon? The install team actually opted for a ducted system. However, the professionals were able to put many of the ducts into closets and out-of-view areas, minimizing the alterations to the mansion. Installers also placed the main air conditioner 200 yards away from the house, hidden behind some trees, to reduce noise and maintain the historic feel at the residence.

Mount Vernon's system also tracks humidity and adjusts to ensure that condensation, which could damage artifacts as well as woodwork, never develops. Consequently, the temperature inside Mount Vernon tends to be only about 15 degrees cooler than the outdoors, rather than staying in the ultra-cool 70s may people are accustomed to.

Mount Vernon and other historic or aging homes are treasures, and if you're lucky enough to own an older home, you no doubt want to preserve it as much as possible. You can maintain your home and still enjoy cool air when you partner with a professional HVAC team. These technicians can install or maintain your air conditioning system in ways that ensure your home preserves its unique character.