Modelling and experimental validation of mattress modified with PCM to improve the thermal comfort of homeless

Gonçalo Carreira da Silva

Key information

Authors:

Gonçalo Carreira da Silva (Gonçalo Carreira da Silva)

Supervisors:

Rui Pedro da Costa Neto (Rui Pedro da Costa Neto (Rui Costa Neto)); Carlos Augusto Santos Silva (Carlos Augusto Santos Silva)

Published in

11/20/2018

Abstract

In this study, the performance of Phase Change Materials (PCM) to improve thermal comfort of homeless people (outdoors) in Lisbon was studied. For this, several EnergyPlus simulations were performed. These simulations were made to check the feasibility and best-case scenario of a sleeping system, containing a sleeping bag and a sleeping mat, in the meteorological conditions of Lisbon. Two parameters were studied: PCM melting temperature and PCM quantity. This EnergyPlus model was validated using real measured data from experimental simulations in which a subject slept for 8 hours in an ambient controlled room. It was concluded that a PCM sleeping system (system composed of a normal sleeping bag and a PCM-filled sleeping mat) improves thermal comfort in the subject when in steady-state with the surroundings, whereas in the first 30 minutes it takes longer to heat up the system. For Lisbon winter meteorological conditions, the best tested PCM was one with melting temperature of 22 ºC. Ideal PCM melting temperature would be 28 ºC for outside mild temperatures around 20 ºC. It was corroborated that measuring skin and thermal surfaces’ temperature was an appropriate tool to compare sleeping systems.