The effects of varying indoor air temperature and heat gain on the measurement of retrofit savings
- Univ. of Dayton, OH (United States)
- New Horizon Technologies, Butte, MT (United States)
Many methods of estimating energy savings from measured weather-dependent energy consumption data attempt to compensate for varying weather conditions between the pre- and post-retrofit periods by identifying an empirical model of pre-retrofit energy consumption and outdoor air temperature. Even though the pre-retrofit model may include a balance-point or change-point temperature, savings determined using this method implicitly assume that the indoor air set-point temperature and internal heat gains are the same during the pre- and post-retrofit periods. In this paper, the authors develop simplified expressions that suggest that estimates of retrofit savings are highly sensitive to minor changes in indoor air temperature and internal heat gains between the pre- and post-retrofit periods. This observation is confirmed in a mobile-home weatherization study where savings estimated with and without considering changing indoor air temperature varied by as much as 89%. These findings suggest that in simple buildings, the accuracy of estimated savings can be significantly improved by routinely measuring both indoor and outside air temperatures and explicitly including them in the baseline model for estimating savings.
- OSTI ID:
- 687652
- Report Number(s):
- CONF-980650-; TRN: IM9944%%317
- Resource Relation:
- Conference: 1998 ASHRAE summer annual meeting, Toronto (Canada), 20 Jun 1998; Other Information: PBD: 1998; Related Information: Is Part Of ASHRAE transactions 1998: Technical and symposium papers. Volume 104, Part 2; PB: 1511 p.
- Country of Publication:
- United States
- Language:
- English
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