President Carter's spurs to the national energy conscience means business for the acknowledged leader in the insulation business.

Owens-Corning Fiberglas Corp., with 21 domestic plants a dozen international affiliates, has twice the capacity for making building insulation as each of the other two domestic producers, Johns Manville and Certain-Teed.

Owens-Corning says it has the capacity to make 940,000 tons of fiberglass insulation last year but gives no figure on acutal production.

The federal government says the industry shipped over a mill on pounds last year. And last fall, Merrill Lynch, Pierce, Fenner & Smith analysts estimated capacity at 1.25 billion pounds for Owens-Corning, 500 million pounds for Johns Manville Corp., 600 million pounds for Certain-Teed Products Corp. A Merrill LYnch broker estimated the three were operating at 83 per cent of capacity at that time.

Owens-Corning President W. W. Boeschenstein says the company will benefit both from new home building and from renovation in months ahead.

"The added impetus of a government energy program will likely accelerate the reinsulation trend which has been on-going for the past several years, as well asincrease per unit demand for insulation in new construction," he said.

Beyond that, until more details are available, including legislative action, it is difficult to assess overall implications of a government program."

Boeschenstein said in the past 2 1/2 years, 8 million of the nation's 40 million homeowners have added to existing home insulation.

Carter proposed a tax credit of 25 per cent of the first $800 and 15 per cent on the next $1,400 spent to insulate buildings.

A do-it-yourself homeowner in Cincinnati, the firm said, can add six incles of insulation to his attic of 1,370 square feet for about $275.

The firm said a builder can fully insulate an average new house in Cincinnati for about $1,200. That would be for the companys recommended insulation in a 1,200-square-foot attic, a 1,000 square foot basement, and all outside walls.

This would give 3 3/4 inches of insulation in outside walls, 9 1/2 inches in the attic and a lesser amount under floors.

The figures were chosen from a computer analysis Owens-Corning conducted on 71 cities and considered local temperatures, energy and insulation costs.

Types of Insulation

Housing experts say that if a home was built before 1960, there's a good chance it has no insulation in the exterior walls.

They estimate that a home's heating bill can be reduced up to 40 per cent if the walls are insulated. It can be done by filling the wall cavity with a blow-in insulation, or applying an exterior layer of sidewall insulation and nailing up new siding over it.

Cavity fill insulation is installed through either the interior or exterior wall. A hole about two inches in diameter must be drilled between each set of 2 by 4 wall studs. If there are fire stops and cross bracing in the wall, extra holes must be drilled.

The insulation is then blown when pressure into the wall cavity, and the holes are covered with wood or plastic plugs. Installation generally is done from the exterior, where a panel of siding can be removed and replaced after insulation to eliminate visible holes. In a brick home, holes can be drilled in the mortor or bricks can be removed to permit the insertion.

There are four basic types of blown-in, cavity fill insulation materials - fiberglass, cellulose, rock or mineral fiber wool and a form known as urea formaldehyde. They usually are installed by insulation contractors. Here are the characteristics of each, including a comparison of R. value (the thermal resistance of the material):

Fiberglass is fireproof (it melts at 800 degrees) and vermin and insect proof.Although it has an R value of 3.5 per inch, the tufts are easily caught up on projections or obstacles within the wall. There can be gaps and eventually the material settles.

Cellulose is a wood-fiber material, finely ground, blown in under high pressure because settling is the worst problem. It has a high R value (3.7) but the lowest melting point (350 degrees) of the four insulation materials.

Wool is preferred by many contractors because it is heavier and easier to keep from hanging and settling in the wall. It melts at 2000 degrees and has an R rate of 3.3 per inch.

Urea formaldehyde is the top of the line in blown insulation. It costs 20 per cent more than other varieties, but gives the highest R value (4.8). it is installed through a hose that mixes its component chemicals at the nozzle and inserts the material in the consistency of shaving cream. The foam easily can fill around any obstructions in the cavity. It's biggest drawbacks are possible shrinkage and odor.