Draw a line across the country at the latitude of lower Pennsylvania .
Any house built now below that line without air conditioning will be obsolete in 10 years .
Fortunately , it is the FHA which has arrived at this conclusion , for it means that cooling equipment of all kinds may now be included in a mortgage , and thus acquired with a minimum of financial stress .
Even if you live above that line , the FHA will back you , for they have decided that the inclusion of air conditioning in all new homes is a good thing and should be encouraged .
New simplified packaged units , recently devised prefabricated glass-fiber ducts , and improved add-on techniques make it possible to acquire a system for an 1800-square-foot house for as little as $600 to $900 .
Two men can often do the installation in a day .
You can install it yourself -- this is a central system that will cool every part of your house .
Its upkeep ? ?
No less an authority than the FHA concurs that the savings air conditioning makes possible more than offset its operating costs .
Is it worth-while ? ?
Home air conditioning has come a long way from the early days of overcooled theaters and the thermal shock they inflicted .
We know now that a 15-degree differential in temperature is the maximum usually desirable , and accurate controls assure the comfort we want .
We know , too , that health is never harmed by summer cooling .
On the contrary , there are fewer colds and smaller doctor bills .
The filtered air benefits allergies , asthma , sinus , hay fever .
Control of temperature and humidity is a godsend to the aged and the invalid .
Heart conditions and high blood pressure escape the stresses brought on by oppressive heat .
Housekeeping is easier .
The cleaner air means less time spent pushing a vacuum , fewer trips to the dry cleaners , lighter loads for the washing machine .
The need for reupholstering , redecorating , repainting becomes more infrequent .
Clothes hold their shape better , and mildew and rust become almost forgotten words .
It will improve your disposition .
When you're less fatigued , things just naturally look brighter .
The children can have their daytime naps and hot meals , and be put to bed on schedule in shade-darkened rooms .
You'll sleep longer and better , too , awake refreshed and free of hot weather nerves .
You can forget about screens , and leave the storm windows up all year around .
Best of all , central air conditioning is something you can afford .
Like its long-lived cousin , the refrigerator , a conditioner can be expected to last 20 to 25 years or more .
That brings its per-year cost down mighty low .
For any house .
No matter what style your home is , ranch , two-story , Colonial or contemporary , central air conditioning is easily installed .
The equipment won't take up valuable space either .
It can go in out-of-the-way waste space .
But there's no denying that the easiest and most economical way to get year-'round whole-house air conditioning is when you build .
If that's done , the house can be designed and oriented for best operation , and this can mean savings both in the size of equipment and in the cost of the house itself .
If you can't see your way clear to have summer cooling included when building , by all means make provision for its easy adding later .
Manufacturers have designed equipment for just such circumstances , and your savings over starting from scratch will be substantial .
If your house is to have a forced warm air system , cooling can be a part of it .
This costs less than having a completely separate cooling system , for your regular heating ductwork , filters and furnace blower do double duty for cooling .
You can get year-'round air conditioners in the same variety of styles in which you buy a furnace alone -- high or low boy , horizontal or counterflow .
The units can be installed in basement , attic , crawlspace , or in a closet located in the living area .
The cooling coil is located in the furnace's outlet .
From the coil small copper pipes connect to a weatherproof refrigeration section set in the yard , garage , carport , or basement .
If you plan to add cooling later to your heating system , there are things to watch for .
Be sure ducts that require insulation get it when they are installed .
They may be inaccessible later .
Be sure your ducts and blower are big enough to handle cooling .
This is especially important if you live in a mild-winter zone .
Be sure you get a perimeter heating system , and diffusers that will work as well for cooling as they do for heating .
You can get a hot water system that will also work for cooling your house .
For cooling , chilled water is circulated instead of hot water .
Instead of radiators you'll have cooling-heating units , each with its own thermostat .
These systems are more expensive than year-'round forced air systems .
The minimum cost for an average one-story , 7-room house with basement , is likely to run $1500 above the cost of the heating alone .
Separate systems .
If the problems of combining cooling with your heating are knotty , it may be cheaper to plan on a completely separate cooling system .
The simplest kind of separate system uses a single , self-contained unit .
It is , in effect , an oversize room conditioner equipped with prefab glass-fiber ducts to distribute the cooled , cleaned , dehumidified air where it is wanted .
In a long , rambling ranch , two such units can be installed , one serving the living area , the other the sleeping zone .
In a two-story house , one unit may be installed in the basement to serve the first floor , another in the attic to cool the second .
In each case , having separate systems for living and sleeping areas has the advantage of permitting individual zone control .
The heat pump .
One of the more remarkable of the new cooling systems is one that can be switched to heating .
As you know , a conditioner makes indoor air cool by pumping the heat out of it and then releasing this heat outdoors .
A relatively simple switching arrangement reverses the cycle so that the machine literally runs backward , and the heat is extracted from outdoor air and turned indoors .
Up until recently , this heat pump method of warming air was efficient only in areas of mild winters and when outside temperatures were above 40 degrees .
Now , the machine has been improved to a point where it is generally more economical than oil heat at temperatures down to 15 degrees .
You can get this added heating feature for as little as $200 more than the price of cooling alone .
Consider it as a standby setup , at negligible cost , for those emergencies when the furnace quits , a blizzard holds up fuel delivery , or for cool summer mornings or evenings when you don't want to start up your whole heating plant .
What size conditioner ? ?
How large a cooling unit you need , and the method of its installation , depends on a variety of factors .
Among other things , besides the nature of your house and how much heat finds its way into its various rooms from the outside , it will depend upon your personal habits and the makeup of your family .
Families with children usually don't want the house quite so cool .
If you are a party thrower , you may need added capacity .
The body is a heat machine , and 20 to 25 guests can easily double your cooling load .
Cooling requirements are best expressed in terms of Aj .
A BTU is a unit of heat , and the BTU rating of a conditioner refers to how much heat your machine can pump out of your house in an hour .
A very rough rule of thumb is that , under favorable conditions , you'll need 15 BTU's of cooling for every square foot of your house .
This is if outdoor temperatures have a high average of 95 degrees .
You'll need more if the high average is above that , less if it's below .
Coolers are also rated by tons .
A ton of cooling compares to the cooling you get by melting a ton of ice .
By accepted definition , a 1-ton conditioner will provide 12,000 BTU of cooling in one hour .
You may find a conditioner rated by horsepower .
It is generally an inaccurate method of rating , for the horsepower is that of the compressor motor , and many other components beside it determine how much cooling you'll get .
A 1-hp conditioner , for example , may vary in effectiveness from under 8,000 BTU to well over 10,000 Aj .
The safest procedure is to let your builder estimate the size of the unit you need , rather than trying to do this yourself .
Don't urge your builder to give you a little extra cooling capacity just to be sure you have enough .
Better to have your equipment slightly undersized than too big .
Here's why :
Reducing humidity is often as important as cooling .
An oversize unit will cool off your house quickly , then shut down for a long period .
Before it cycles on again , humidity can build up and make you uncomfortable even though the temperature is still low .
With a unit of the right size , a compressor will run continuously during hot weather , reducing humidity as evenly as it does temperature .
Money-saving tips .
Attention to details can cut in half the size unit you need and pare operating expense proportionately .
A well-designed , 1200-square-foot house can be comfortably cooled and heated for as little as $128 a year , or $11 a month .
If you have a house which heat doesn't penetrate easily , your unit will have less heat to remove .
Keep the direct sun from reaching the house and you've won the first battle .
In a new house , generous roof overhangs are a logical and effective solution .
If the house you plan to buy or build won't have big overhangs , you can still do a fair job of keeping the sun off walls and windows with properly designed trellises , fences and awnings .
Shade trees , too , are a big help , so keep them if you can .
Drawn blinds and draperies do some good , but not nearly as much as shading devices on the outside of the house .
The more directly the sun strikes walls and roof , the greater its heat impact .
The way a house is set on its lot can therefore influence how much cooling you're going to need .
A shift in the walls , or a change in the roof slope , so the sun hits them more obliquely , can save you money .
You can use heat-absorbing glass to stop the sun , double glass and insulated glass to combat condensation .
Restrict large glass areas to the north and south sides of the house .
They're easier to shade there .
An attic space above insulation makes a house easier to cool .
You'll even gain by putting your water heater outside the conditioned space , and using an electric range instead of a gas one .
Gas adds to the moisture load .
Insulate , weatherstrip , double-glaze to the maximum .
In insulation , the numbers to remember are 6-4-2 .
They stand for 6 inches of mineral wool insulation in the ceiling , 4 inches in the side walls , 2 inches in the floors .
Such extra-thick insulation not only permits a much smaller cooling installation , but will continue to reduce operating expenses both in heating and cooling .
A light-colored roof will reduce sun heat by 50 per cent .
It costs two to three times as much to remove a BTU in summer as it does to add one in winter , so every solitary BTU is worth attention .
You'll foil them in droves , along with their pal humidity , by having and using a kitchen range exhaust fan , a bathroom ventilator for when you shower , and an outside vent for the clothes drier .
Keeping conditioners quiet .
It's no use pretending that all conditioners are quiet , but the noise they produce can be kept to a minimum .
Good workmanship is important in the installation , so if you're doing your own contracting , don't award the job on the basis of price alone .
Avoid attic placement directly above a bedroom .