Analysis of ineffective heating in intermittently heated office buildings in hot summer and cold winter areas

ABSTRACT

To reduce room heating energy consumption and improve energy utilization efficiency, this paper proposed a method for evaluating the energy efficiency of office heating based on ‘ineffective heat supply’ and ‘ineffective heat supply ratio’ and established an energy consumption analysis model. Using the office in hot summer and cold winter areas as an example, the heating energy consumption and energy utilization efficiency were simulated. The results indicate that better thermal comfort is achieved in the working area of Air Conditioning Lower Installation (ACLI) compared to Air Conditioning Upper Installation (ACUI). The ineffective heat supply ratio of the room increases with the rise of air supply temperature and decreases with the increase of air supply speed. As the supply air temperature increases from 25°C to 50°C, the ineffective heat supply ratios for ACUI and ACLI increase by 35.9% and 14.9%, respectively. The use of low-temperature heat medium is more energy-efficient than high-temperature heat medium. When the air supply speed increases from 0.8 to 3.2 m/s, its ineffective heat supply ratio decreases by 44.6% and 7.8%, respectively. Air speed change significantly impacts ACUI's ineffective heat supply ratio, with ACLI more energy efficient at lower speeds.

KEYWORDS:

• Heating
• office buildings
• air conditioning installation methods
• temperature gradients
• thermal energy utilization efficiency

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was partially supported by the Natural Science Foundation Program of Hunan Province [grant number 2023JJ30586].