Central Cooling: Ducted Systems

Ducted cooling systems are typically installed in homes that use hot water or steam heat. The following information is for homes that don't already have ductwork that can be used for a central cooling system. A new duct system is used to circulate the cool air throughout your house. We have described below exactly the steps we take to install cooling system we have proposed for your home.

Determining Capacity
We do specific calculations in order to determine how much heat your house absorbs each hour during the summer months. The major factors which determine the amount of heat gain are the size of your house, the number and compass orientation of windows, and the amount of exposed roof area.

The quantity of heat gain is measured in BTUs - every 12,000 BTUs equals one ton of cooling. Heat gain is calculated in total number of BTUs per hour. When we select the central cooling equipment for your home, the heat gain (cooling figure) will determine the capacity of the equipment we install. It is important that we install neither too much nor too little cooling. If the equipment is undersized for cooling, the house will not be cold enough on hot days. If the equipment is oversized for cooling, the indoor air will not be properly dehumidified, and will feel cold and clammy.

The Outdoor Unit Base
We prepare a permanent base for the new outdoor condensing unit. This base is installed at a location chosen jointly by you and our staff. Most often, we dig a hole to provide a layer of rock gravel approximately 4 inches thick, and then pour a 3-inch concrete slab on top of the gravel under-layer. We invest extra time and effort in preparation of the condensing unit base, because we have found that the less vulnerable the condensing unit is to frost heaves, the longer your investment lasts.

The Outdoor Unit
We place the new outdoor condensing unit on the base which we have prepared. The capacity (B.T.U. rating) of the outdoor condensing unit will be determined by the measurements we take of your home at the time we prepare your quotation.

The Indoor Coil
We place the properly matched cooling evaporator coil inside your duct system. This coil is placed on top of your existing or new furnace.

If you continue to use your old furnace, we may remove a section of ductwork and install a new specially fabricated ductwork "plenum" to contain the new cooling coil. We may also install a new more powerful blower motor inside the furnace itself. If we need to take this step, we will have included the new blower motor in our quotation.

The Refrigerant Piping
We also install two new copper pipes (parallel to each other) to connect the indoor coil and the outdoor condensing unit. One of the pipes will be wrapped in special insulation to keep it from sweating moisture. These pipes contain the refrigerant gas (Freon) which takes the heat from your home to the outdoors.

The Condensate Drain Piping
We install a separate drain pipe from the indoor cold coil to either a local drain, or to the outside of the house. This drain line transports the moisture (humidity) which is removed from the indoor air at the cooling coil. We may also install a small pump to assist this drain depending on the route of the drain line piping.

If your air handler is going to be located in the attic, we will install an overflow drain pan with an electrical shutoff switch underneath the air handler. This additional drain pan will help protect the ceiling below from water damage which could be caused by a clogged condensate drain.

The Duct System
We install a new duct system in spaces discussed (usually the attic or the basement) at the time we visit your home. The cooled air circulates through this duct system to the rooms you have chosen to cool.

The ductwork we install is made of sheet steel. We make all final connections to registers and grills using short pieces of flexible ductwork in order to provide the quietest possible operation. We install air dampers within the duct system in order to allow us to fine-tune the amount of air flowing to each supply grill in the house.

Any duct we install in exposed areas (like a crawl space, or the attic) is wrapped with thermal insulation to insure that no cooling is lost to non-conditioned spaces.

At the connecting fittings between the duct system and the air handler (the supply and return air plenums), we install special sound absorbent insulation inside the ductwork to insure that you do not hear any excess fan noise through the duct system.

We install metal air registers and grills at locations we discuss with you.

Hard metal duct and grills provides the best quality and longest lasting air delivery system. Hard metal duct takes somewhat longer to install than flexible ductwork. However, once installed hard metal ducts will not degrade or collapse during the years you use your cooling system.

The Thermostat
We install a sub-base under your existing thermostat. This sub-base will have a switch which allows you to choose "cool", "heat", or "off".

Conclusion
These basic steps make up all cooling installations. You may also want estimates on additional accessories which you may choose to install at the same time as your new cooling system, including air cleaning devices, a humidifier (for winter comfort), or an electronic set-back thermostat.

National, State, and Local Safety Codes
Our experienced and licensed staff believes that these codes are a valuable system to ensure systems are installed properly. At Keyes North Atlantic our work always meets or exceeds the code requirements. If you'd like to know more about our licenses and credentials, we welcome you to the Insurance and Licenses portion of our Credentials section.

Insurance
We are fully covered for workers compensation insurance, and we carry two million dollars of general liability insurance. We are happy to forward certificates of insurance coverage to you for your records. Or view them right here in the Insurance and Licenses portion of our Credentials section.

Warranties and Guarantees
We provide a full one-year guarantee on our work, equipment, and materials. This guarantee is provided in addition to the warranties, which the manufacturers provide on the equipment that we install in your home. Click here for more information on our workmanship warranty.