Mid-Century Heating and Cooling

In Mid-Century homes, heating and cooling systems were quite different from what we see today. Let's go over the common types of systems used during that era, how to maintain them, and when it might be time to replace them.

Heating Systems

Forced Air Furnaces:

Forced air furnaces were one of the most common heating systems. These furnaces burned oil, gas, or coal to heat air, which was then distributed throughout the home via a network of ducts. Many homes built in this era still have these systems, though the fuel source might have been updated.

One of the biggest things to watch out for in older forced air units is the presence of asbestos in the insulation material that wraps the pipes. You can read more about asbestos in Mid Century homes here.

Radiant Heating:

Radiant heating was popular in Mid-Century homes, especially in floors or walls. These systems used electric heating cables, hot water, or steam pipes embedded in the floor or ceiling to warm the house. The heat radiates directly from these surfaces, creating a comfortable and even warmth without the need for ducts.

Gravity Furnaces:

Gravity furnaces, also known as "octopus furnaces" because of their large, tentacle-like ducts, used convection to distribute heat. Hot air naturally rises through the ducts, and as it cools, it sinks back down to the furnace. These systems were usually powered by gas or oil.

These types of systems may look a bit ridiculous from above, but the major advantage is not having to hide ductwork on the interior of the house, preserving beautiful clean lines. Oftentimes when homeowners want to upgrade to a more modern duct system, they need to use soffits to hide the ductwork, as many Mid-Century homes didn’t have attic space at all to preserve the open beam ceilings that many of us love.

As long as these octopus systems can’t be visually seen from the ground level, they can be an excellent way to heat and cool while respecting the architectural nature of a Mid-Century home.

Cooling Systems

Evaporative cooling systems, commonly known as "swamp coolers," were popular in homes built during the 1950s and early 1960s, particularly in dry, arid regions of the United States, like Los Angeles. These systems offered a cost-effective and energy-efficient alternative to traditional air conditioning, which was still relatively new and expensive at the time. 

How Evaporative Cooling Systems Work

Evaporative coolers operate on a simple principle: evaporation. When water evaporates, it absorbs heat from the surrounding air, causing the air temperature to drop. Here’s how it works in a home setting:

The cooler pulls in warm, dry air from the outside through vents. This air passes over water-soaked pads inside the unit. The water in the pads evaporates, absorbing heat from the air in the process. As the water evaporates, the air cools down significantly. This cooled air is then blown into the home.

Unlike traditional air conditioners, evaporative coolers need a constant supply of fresh air. The cooled air flows through the house, and the warmer, stale air is pushed out through open windows or vents.

Though most folks who purchase Mid-Century homes will eventually want to upgrade to a more traditional duct-based AC system, a properly working Evaporative Cooling system will work just fine for many as long as it is properly maintained.

Plus, you’ll likely have to upgrade the electric panel to actually run a modern AC system. Read all about electric wiring and panels in Mid-Century homes here.

If you do choose to keep your Evaporative Cooling systems, here are some positives.

Energy Efficiency:
Evaporative coolers use significantly less energy than traditional air conditioners. They don't rely on compressors or refrigerants, which are the main energy hogs in AC systems. This makes them a more eco-friendly and cost-effective cooling option.

Low Operating Costs:
Because they use less electricity, evaporative coolers are cheaper to run. They’re also simpler in design, which generally means fewer parts that can break down, reducing maintenance costs over time.

Adding Humidity:
In extremely dry climates, evaporative coolers have the added benefit of increasing indoor humidity levels, which can make the environment more comfortable. This is particularly valuable in desert areas where the air can be uncomfortably dry.

Fresh Air Supply:
Evaporative coolers continuously draw in fresh air from outside, which is then filtered and cooled. This constant influx of fresh air can improve indoor air quality, especially when compared to traditional air conditioning systems that recirculate the same air.

Common Maintenance Needs

Regular Cleaning:
Evaporative coolers require regular cleaning to maintain efficiency. The water-soaked pads inside the cooler need to be cleaned or replaced periodically to prevent the buildup of minerals and debris, which can reduce the system’s effectiveness.

Water Supply Maintenance:
Since these systems rely on water to cool the air, ensuring a steady and clean water supply is crucial. You’ll need to check for any leaks, clogs, or issues with the water pump. In Los Angeles, an area with hard water, mineral buildup and corrosion can be a problem, so a water softener or regular cleaning of the reservoir might be necessary.

Seasonal Shutdown:
In climates with cold winters, evaporative coolers need to be properly shut down at the end of the cooling season. This typically involves draining the water, cleaning the unit, and covering it to protect it from the elements. Often these units are located on rooftops, which adds a degree of complexity to this task.

Checking the Motor and Fan:
Like any mechanical system, the motor and fan in an evaporative cooler require periodic checks. Lubricating moving parts and ensuring that the fan is balanced and free from obstructions can extend the life of the unit.

When to Replace or Update Your Evaporative Cooler

If your evaporative cooler isn't providing the same level of cooling it once did, it might be time for a replacement. Over time, the pads can become less effective, and the system's components can wear out, leading to a decline in performance. Modern evaporative coolers offer features like programmable thermostats, variable-speed motors, and more efficient designs. If your system is outdated, upgrading to a newer model could provide better cooling performance and energy savings. Since these systems are outdated, parts and service for them may be more challenging to come by, so if they start to go bad, it might be time to upgrade.

Other types of cooling for Mid-Century  homes include attic fans, which were used to draw hot air out of the house, making it cooler inside. While they didn't cool the air directly, they helped reduce indoor temperatures by improving ventilation. Many Mid-Century homes in the valley of Los Angeles use fans in combination with more traditional types of AC, and the right fan can really complete the Mid-Century look.

And, for the right person, an abundance of windows that can be opened may be all the cooling one needs!