Can existing heating ducts be salvaged for cooling? Because cooling generally calls for bigger ducts than those needed just for heating, have a trained dealer measure your existing ducts to see if they are big enough. “Heating ducts almost always work out,”. says one top engineer, “but some modifications may be needed.” You may need a bigger trunk line in the basement or an extra duct run to a big room facing south. (“The easiest room to heat in winter is often the hardest to cool in summer.”) Ductwork is the most expensive part of the installation so it rates thorough advance planning.
Can you keep the existing warm air outlets? Proper air diffusion is far more important for cooling than heating. Air conditioning usually calls fora double-deflection type of air outlet—one with both vertical and horizontal louvers that can be opened, closed or slanted so the right amount of air is diffused in the right direction for each room. If your warm air outlets are plain metal grilles with fixed louvers they probably should be replaced.
Is the furnace blower big enough for cooling, too? In about half of the cases, yes. If so, you can save by buying a stripped-down summer cooler that hooks up the furnace fan.
What can you do if your house has hot-water heat or no central heat? You can put in a chilled-water system, console units or window units. In many houses, however, engineers say that a ductwork system still is your best bet, furring down the ducts in a central hall, for instance, with short ducts branching out to the rooms around. The hot water boiler remains for heating.
Is the present wiring adequate? Most air-conditioning systems need at least a separate 220-volt, 30-ampere circuit wired straight from the main electric board.
The board itself should normally have a capacity of at least 60 amperes for the whole house, preferably 100 amperes. The size of the board is usually marked on the cover. Another solution is a gas-operated air conditioner which only needs a relatively small amount of electricity to run its blower.
Which is the best cooling system for a particular houllse? There are six prin- cipal types, abut one being the same as used in new houses. Here are the advantages and disadvantages of each: