Can Air Conditioning Be Added to Your Century Home?

The answer is yes, it is possible to install air conditioning in a turn of the century home. If you live pretty much anywhere besides the arctic, it's not only possible, but vitally necessary in the summer. There are however some specific challenges involved in this endeavor that must be borne in mind.

The main problem is that in the past, we're talking the turn of the 20th century and prior, houses simply weren't designed with air conditioning in mind because air conditioning as we know it today didn't exist. Houses were cooled by ventilation or at most primitive fans. In contrast to this, modern houses are built by the building contractor with central air conditioning as part of the construction process. When the house is only at the framing stage ducts are placed in the walls and air conditioning units are discreetly placed in basements or interior and exterior walls. When the walls are covered up with drywall on the inside and whatever sheathing material is used on the outside, you hardly know it's there.

Installing central air conditioning in an old house is a different matter. To go back and retrofit an air conditioning system in a house that wasn't designed for this purpose means that you will have to open up the walls or do other extensive remodeling, such as building new walls in front of the old ones, in order to place the AC units ducts where they can't be seen. Neither of these are very attractive options. They mean damaging walls that are already time worn and in general marring the appearance of an historic structure. Even if you are able to place supply and return ducts in unobtrusive places such as basements, attics, and bathrooms, you will still have to put air registers in these locations and alter them in some way.

On top of this, there may be radiator heating systems involved in old houses, further reducing the space available for AC units and duct work, or otherwise interfering with their installation. In old houses designed before even heating systems were common the situation can be even worse. Internal wall space can be hit or miss because the houses weren't even designed for continuous spatial flow inside the walls for anything but simple plumbing.

The fact that crumbling plaster and lath strips have to be torn off to even get access to whatever interior space is available means you will be in for a definite construction project rather than a simple installation procedure. And these houses, often dating from the mid 18th to mid 19th centuries, are even more worthy of preservation, so remodeling is really not an optimal solution.

Fortunately there are indeed other options. Retro fit systems specifically designed for placement in old houses are readily available and can be installed by a qualified heating contractor. Though these systems themselves often cost more, the reduced construction costs and insulation time often makes up for it.

One such option is what is known as a high velocity system. This consists of thin insulated tubing that can be snaked through an old house to deliver cool air. The reduced size means that it fits easily into many walls, and the need for large scale remodeling is minimal.

A slightly less expensive option, called a mini split system, only requires placement of small cooling units and blowers on a room by room basis. These units are connected by thin power and coolant lines to a larger outdoor unit that consists of a compressor and fan. In both these cases, the size of the AC work being installed is much less, meaning only minor invasive remodeling need be done to find a space for them. These systems are great solution to putting central air conditioning in an old house, but it is important to find a qualified heating contractor to install them. Make sure that the contractor you use has specific experience with the type of system you are considering, is licensed and certified, and matches the size of the system to the size and heating/cooling requirements of the old house. He should be able to show you Manual J and Manual D calculations concerning your house size from a heating and cooling standpoint, not merely estimate these numbers.

The only other common option to all this is to put free standing window air conditioners in the house. And we all know how noisy, bulky, and unattractive those can be, especially looking from the exterior of the house. If you want to preserve the beauty and integrity of an historic house, considering doing things right and getting a properly sized and installed retrofit air conditioning system put in. Your comfort is important, and the structural and aesthetic integrity of your old house is important as well.