61.   Ecology also won out over economy when it came to selecting a heating system.

62.   Electric heaters cause less problems for patients, but any heating system can trigger problems for allergy patients just by doing its job.

63.   Equipped with a pump and a heating system to create steam, it required hands-on operation during the frothing process.

64.   Even the most efficient heating system will fail to keep a room warm if cold air is allowed to enter through the gaps and cracks in an old window.

65.   For example, in a forced-air heating system it is essential to change the air filters periodically.

66.   Fifteen deaths have been blamed on the storm, mainly victims of hypothermia or carbon monoxide poisoning by makeshift heating systems.

67.   First the heating system died, then water started dripping through the ceiling.

68.   For most people, the greatest hardship was the cold as home heating systems shut down.

69.   For starters, take Russian heating systems.

70.   Forced-air, hot water and steam are the most common heating systems in the United States.