Modeling of Uncontrolled Indoor Humidity for HAM Simulations of Residential Buildings

Moisture balance methods have been developed to estimate the indoor humidity in residential buildings that are without mechanical humidity control. Inaccuracies in the assumption of the indoor humidity can result in misleading results from heatair-moisture models because the models are highly sensitive to the indoor humidity as it is one of the boundary conditions for the simulations.

This paper examines the current approaches to modeling the indoor humidity for use in heat-air-moisture computer simulations. Included in the discussion is the range of parameters published for calculations employing moisture balance methods, and how these methods and the selection of these parameters must further evolve.

This paper makes the case for establishing parameters that are different for non-heating and heating seasons. Calculations of indoor humidity are presented for a representative mild marine climate and it is demonstrated that the controlling parameters must be carefully selected to produce realistic indoor humidity levels.

Author: Patrick Roppel, Mark Lawton, William C. Brown