Improved modelling of HVAC system/envelope inteactions in residential buildings
General building energy simulation programs do not typically simulate interactions between HVAC systems and building envelopes. For this reason, a simulation tool which includes interactions between duct systems, building envelopes, and heating and cooling appliances in residential buildings has been developed. The simulation tool uses DOE- 2 (to model space conditioning loads and zone temperatures), COMIS (an airflow network solver), and a model of duct leakage and conduction losses. Three augmentations to the simulation tool are presented herein, along with sample results. These include: (1) modeling of steady-state thermosiphon flows in ducts, (2) improved simplified modeling of duct thermal mass effects, and (3) modeling of multi-speed space conditioning equipment. Multi-speed air conditioners are shown to be more sensitive to duct efficiency than single-speed equipment, because their efficiency decreases with increasing cooling load. Thermosiphon flows through duct systems are estimated to be 5-16% of the total heating load, depending on the duct insulation level. The duct dynamics model indicates that duct thermal mass decreases the energy delivery efficiency of the distribution system by 1-6 percentage points.
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States); California Inst. for Energy Efficiency, Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 273737
- Report Number(s):
- LBL-36048; CONF-950336-31; ON: DE96012515
- Resource Relation:
- Conference: American Society of Mechanical Engineers/Japanese Society of Mechanical Engineers/Japan Solar Energy Society international solar energy conference, Lahaina, HI (United States), 19-24 Mar 1995; Other Information: PBD: Mar 1995
- Country of Publication:
- United States
- Language:
- English
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