While 98 per cent of the readings in Springburn Academy, Smithycroft Secondary, Lourdes Secondary, Rosshall Academy, St Mungo's Academy, and Hillpark Secondary met Government-recommended guidelines, engineers found problems with both the equipment and facilities management of the heating system.
Willie Hart, local secretary of the Educational Institute of Scotland, has challenged Glasgow City Council to carry out a full survey to see if claims that some of the schools built or renovated under public private partnership (PPP) funding are "sick buildings" have any substance.
Gordon Morris, a heating and ventilation expert who undertook part of the investigation for the council, found basic technical problems with the schools' building management system, which records temperatures taken by sensors located in various zones.
There was "a basic accuracy problem" with the sensors and their location made them particularly sensitive to direct sunlight and wind chill.
Mr Morris also drew attention to exposed pipework which he said contributed unwanted heat regardless of the temperature the classroom was set to be at.
Radiator valves were found to default to the full-on position if tampered with, which interfered with heat emission control.
Amey Miller Construction Joint Venture, on behalf of the 3Ed Glasgow consortium which built and manages the schools on behalf of the council, also investigated the heating systems and found problems with radiator valves and pumps.
It also noted that janitorial staff were having difficulties operating the "somewhat complex" heating system and the solar blinds and windows effectively to avoid heat build-ups during particularly warm days.
During the 10-week investigation, engineers made 6,073 visits to 898 classrooms across the six schools. The rooms visited were determined by the staff in the schools where there was said to be a problem.
They found that on only 45 out of 6,073 readings were the classroom temperatures actually running at 27C or above. These 45 events occurred in 13 different rooms, of which six housed business studiesICT, five housed home economics, two were general purpose classrooms and one was an office.
A report to Glasgow's education committee yesterday (Thursday) by John Curley, head of ICT and schools, stated: "An analysis of the type of classroom where the temperatures rose to 27C or more during the period indicated that these were, in the main, business studiescomputing rooms and home economics cookery rooms. This is not surprising given the additional heat generated by computers andor cookers."
Solutions proposed include better training for janitorial staff in operating the heating system; a recalibration by 3Ed of the heating sensors; relocating sensors to more suitable positions; giving teaching and support staff the ability to change the thermostatic radiator valve settings in their rooms; insulation of exposed pipes; and piloting the use of mobile air-conditioning units in business studiesICT and home economics classrooms.
Mr Hart said: "The EIS welcomes any practical solution which might either prevent or reduce the opportunities for difficulties with heating and ventilation. But fundamentally we still think these are sick buildings and they require a more in-depth look at what is causing the difficulties."