Collection and Storage of Solar Gains Incident on a Radiant Floor in Highly Glazed Houses

Large amounts of south facing windows can help reduce heating demand in the winter and shoulder seasons by allowing high levels of solar radiation to enter the building. One problem that may arise from large areas of south facing glazing is overheating of the adjacent rooms, even in the winter. Cooling of the floors may provide a means to prevent overheating in such a situation. Cooling a floor prevents the portion of solar gains absorbed by the floor to be transferred to the space by convection or infrared radiation. This cooling can be achieved with the use of water pipes in the floor. The heat removed, and upgraded to a higher temperature with a heat pump, can then either be stored in a thermal storage tank for later use, sent to another zone that requires it, or used to preheat domestic hot water. Such a system has the potential to greatly reduce space heating and domestic heating requirements in houses in Canada. This thesis investigates such a system for a house in Canada. In periods of overheating, the solar gains are absorbed by the floor cover and collected by the cold pipes in the floor. The heat is upgraded by a heat pump and stored in a hot storage tank. Building simulation was used to evaluate the potential energy savings for such system. This active/passive radiant floor solar collection system was found to be able to reduce energy demands by as much as 27% compared to a typical house HVAC system. In order to model the system, existing models for embedded tube radiant floor systems were compared to a finite element simulation. Additionally, an above-floor tube and plate radiant floor model was developed and validated. A transient water-water heat pump model was also developed and validated. The controls of radiant floor heating under high solar gains variation was also studied for various floor constructions.