YuXiang Chen*, A. K. Athienitis, K. E. Galal

Solar Buildings Research Network www. solarbuildings. ca
Department of Building, Civil and Environmental Engineering, Concordia University, Montreal, Quebec,

Canada

Corresponding Author: yuxia ch@alcor. concordia. ca

Abstract

This paper describes the thermal performance assessment of a demonstration solar house with a building-integrated photovoltaic-thermal system (BIPV/T), passive solar design and a ventilated concrete slab (VCS) for solar heat storage, and the modelling of the BIPV/T and VCS. The house was designed to achieve close to net-zero annual energy consumption. Several innovative solar technologies are adopted in this house to meet the design goal. BIPV/T system collects thermal energy from the photovoltaic panels (PV) and cools down PV at the same time. The VCS system stores part of the collected thermal energy in the heating season. Large south facing triple glazed windows and distributed thermal mass are employed for passive solar spacing heating. An integrated supervisory control system is used to optimize the performance of conventional mechanical system and solar energy systems. The house was completed in 2007 and preliminary results are presented. Thermal network simulation models using for the BIPV/T and VCS are presented. It is validated with the measured data and shown to be satisfactory for design and control of the system.

1. Introduction

The Canadian Solar Buildings Research Network is conducting a major research program focused on the design and demonstration of net-zero energy solar buildings under Canadian climatic conditions. The Canada Mortgage and Housing Corporation (CMHC) launched a demonstration initiative, EQuilibrium Housing in 2006. As one of the twelve selected demonstration houses across Canada, the solar house considered in this paper was designed and built in 2007 by a prefabricated home manufacturer in collaboration with the Solar Buildings Research Network. This energy efficient solar house is designed to achieve annually close to net-zero energy consumption through optimal integration of conventional heating technologies such as geothermal heat pump, BIPV/T roof system, passive solar design and active thermal storage (Fig. 1). The house is located near Eastman, Quebec, Canada. Table 1 shows the monthly average dry bulb temperatures of Eastman. The house is designed to accommodate a four-person family. The total floor area is about 140 m2 excluding the 90 m2 basement floor area. A healthy and comfortable home that is energy efficient, and yet affordable, and easy to be constructed is the overall goal of the design.

To achieve the net-zero-energy goal, reduction of the energy consumption for space heating and domestic hot water (DHW) heating is critical. Passive solar design can greatly reduce the space heating fuel consumption [1]. BIPV/T can harvest considerable amount of heat from solar irradiance while producing more electricity due to cooling of the photovoltaic roof. This collected heat can be used for space and DHW heating. In order to maximize the potential utilization of the collected heat from the BIPV/T and the heat transmitted through south-facing windows, thermal mass is needed to store the excess part of this energy and release it later in an appropriate manner [2]. In the case of this house, actively and passively charged concrete slabs and walls are adopted to serve this purpose. Distributed thermal storage integrated in a building has been shown to be efficient and effective in improving the thermal performance of buildings [3, 4]. It can reduce the thermal fluctuation and load, and also shift the peak load. Concrete is a common and effective building material used as thermal mass [5]. Concrete slab, in a distributed form, has its advantages in functioning as thermal storage and structure. Athienitis et al. [2, 6] conducted experiments and simulations to study the thermal behaviour of both passively and actively charged concrete slab in passive solar buildings. Several kinds of VCS have also been studied by several researchers [7, 8].

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