Analysis of school HVAC systems

According to the information on school HVAC systems gathered via the energy questionnaire (available at search.rec.org/outcomes), over half the analysed schools were connected to a district heating system. Constant-temperature gas boilers provided heating in 17 percent of the analysed schools; only 4 percent of the schools used condensing boilers; and 3 percent of school buildings were totally unheated. Other types of heating systems were used in 23 percent of the schools, meaning oil or coal boilers or electrical heaters (e.g. oil radiators)

(
Figure 39).

Distribution of thermal energy production systems used for heating



In the Albanian schools, heating was typically provided by oil-fired boilers, although two of the Albanian schools were unheated, and two schools used electrical heaters that provided heating in only some of the classrooms. Heating systems used in the schools in Bosnia and Herzegovina included gas and oil boilers and district heating. Hungarian schools were mainly heated by gas boilers, with only one school relying on district heating. All the schools in Kazakhstan, Belarus, Ukraine and Slovakia (with the exception of one that used a condensing gas boiler) were connected to a district heating system. In Serbia, 70 percent of the analysed schools used a district heating system, while the others had oil- or coal-fired boilers. Almost all the analysed schools in Tajikistan used electrically powered oil radiators. Some of the Italian schools had advanced HVAC systems: two had photovoltaic plants and condensing gas boilers. The other Italian schools typically had constant-temperature gas boilers, and only one had an oil-fired boiler. In schools using gas or oil boilers, the heating system was usually a two-pipe system; and in schools operating with a district heating system there was generally a one-pipe system in place, with the exception of Serbia, where all the schools had a two-pipe system. Heating appliances in the analysed schools were usually radiators with manual valves, and the heating system pump had a constant speed. Only 13 schools had a variable speed pump. The questionnaires also gathered information about indoor temperature reduction settings during the heating season. In 44 percent of the analysed schools there was no periodical temperature reduction in the heating system: the temperature was maintained at the same level day and night and also at the weekend. In 42 percent of the schools the indoor temperature was lowered at night and at the weekend. In 6 percent of the schools the temperature was lowered only at the weekend, and in 4 percent of the schools it was lowered only at night.

In terms of DHW, over 60 percent of the analysed schools had no supply system; and 18 percent of the schools had an electric water heater. In 10 percent of the schools there were DHW storage tanks heated by gas or oil boiler or by a district heating system. Most of the schools had no air-conditioning system, and only some of the rooms had split units.

 
Ministero Dell'ambiente Italian Trust Fund