Veteran U.S. appeals Judge Albert V. Bryan Sr. patrolled Alexandria's federal courthouse yesterday, blinking at the acrid odor of smoke and ashes drifting from his office down the hall.

Now 82 and technically retired, Bryan was burned out by an early morning fire in the third-floor chambers where he was worked almost daily since President Kenndy named him to the Fourth U.S. Circuit Court of Appeals in 1962.

The FBI said yesterday it would await the results of laboratory tests to determine the cause of the blaze, discovered about 6 a.m. by a courthouse security guard. There were no injuries. Damage was estimated at about $150,000.

Bryan, who regularly rides to work about 8 a.m. with his son, U.S. District Judge Albert V. Bryan Jr., still considers cases as a senior judge. He was concerned, he said, about family photographs on his desk and wall-hung photos of "my predecessors," all of which he declared were "pretty badly smoked."

Inside his charred office, paint, furniture, law books and carpets were destroyed or badly singed. A file room was heavily damaged, but the files, according to the judge, appeared intact. His secretary's telephone and electric typewriter had melted.

Security guard D. A. Hayes said he had reported for work shortly before 6 o'clock when an alarm linked to Judge Bryan's chambers sounded on the ground floor. The office is equipped with a silent "duress alarm" to alert officers to intruders or other difficulty.

Law enforcement officials declined to say whether they believed unauthorized persons had been present in the building at the time. Some postal employes already were at work at they city's Old Town station, which occupies space on the first floor.

Hayes was joined a moment after the alarm by an Alexandria police officer who had been driving by and noticed smoke coming from the courthouse cupola. The two reported the incident and city firemen arrived within minutes.

There was no immediate estimate of when the judge's chambers, a corner suite of offices at the rear of the 51-year-old red brick building, might be repaired.

Bryan, who was elevated to the federal bench by Harry Truman in 1947, yesterday set up shop in the nearby office of U.S. District Judge Richard Williams, who is away.