Businesses at a small boiler manufacturer in Northern Virginia has been booming since this winter's cold weather focused attention on the national shortage of natural gas.

Hydro Steam Industries, Inc., of 3127 Colvin St., Alexandria, this week shipped several large boilers to Midwest locations under contracts signed since Jan. 1. More orders are coming in and the firm is adding to its work force.

According to Dixon F. Hemphill, president and founder of the six-year-ols firm, Hydro Steam may sell as many as 200 of the huge boilers this year.

Generating steam for heating or industrial processes is not new but using electricity to fire steam-heat boiler is relatively new in this country. In Europe, steam has been generated with electricity since the 1930s but the unlimited availability of fossil fuels in North America discouraged the introduction of such boilers here.

Hemphill said he decided to enter the business when the environmental concerns about fly-ash from fossil-fuel-fired boilers appeared to point to the need for a substitute. He purchased rights to the electric boiler design of a Swiss manufacturer.

Currently, the Alexandria company is manufacturing high-voltage-electrode steam boilers in sizes comparable to fuel-fired boilers. Two other companies are in the same business, also with Swiss designs, including giant General Electric Co.

Hemphill literally started his business in the basement of his home and now employs 15 persons. Annual sales are approaching $1 million. Individual boilers cost from $3,000 to $75,000 depending on sizes.

Recent contracts, all places after the cold weather led to shutoffs of natural gas, included a boiler for the City National Bank of Columbus and computer center, to replace a gas-fired boiler, and shipped within eight days; two boilers for the 12-story Midland Mutual Life Insurance building in Columbus, to be placed on standby in case gas was cut off and two boilers for a 25-story office tower in Columbus.

In the last instance, the boiler room is on the 25th floor, and 55-gallon drums of oil were hoisted to the top to fire boilers after gas was shut off.

"This is going to do great things for us," said Hemphill, who is looking at larger quarters in the Springfield area for a possible expansion of production facilities. Hydro Steam has 43 sales representatives across the nation. Businesses in various regions, including electric utilities, have expressed interest in the electric boiler concept.

Hemphill said the efficiency of electric boilers is about 100 per cent in terms of the absence of heat loss. While natural gas remaiins cheaper, its scarcity may force more firms to consider electric-fired boilers, he added.