suitable for fitting buildings with very low thermal stability
induced by light building
construction or thermal insulation positioned above all to internal surfaces.
This article deals with thermal storage walls for waste energy preservation.
The system is based on a solid double layer internal wall with an air canal. Warm air flowing around a fireplace is used for charging wall storage capacity. The energy is emitted to the zone with some time-delay.
1. BACKGROUND
What effects do thermal storage structures have on thermal stability and energy consumption?
It is universally accepted that massive buildings have lower energy consumption if the operating time is permanent. This influence is taken into account in standardized calculations; there is a thermal difference reduction in heat loss calculations. This effect is helpful during the summer because internal air temperature does not increase so much and a massive structure substitutes or supplements a cooling system.
2. CONSTRUCTION DESCRIPTION
An active thermal storage wall is an appliance for increasing thermal stability in low-energy buildings and for excess energy storage. The main heating system is warm-air heating with very a quick start. A warm-air fireplace is placed in a living room and internal thermal storage wall. The fireplace is used for quick short time heating or for air temperature increase. The fireplace is closed, the fuel is wood. Exhaust gasses go to a separate chimney from the fireplace. The thermal storage wall is used for increasing thermal inertia and for excess energy storage from the fireplace. This system supplements central warm-air heating in the building and increases local thermal comfort.
The fireplace is placed in the main living room, which vertically reaches the first floor. Thethermal storage wall is in frontal view on the right from the fireplace and divides the space between the living room and the bedroom. The wall is made from ceramic bricks in this case. The wall construction may be also made from concrete and the construction can be cheaper. Ceramic bricks were chosen for aesthetic reasons. The wall has a hollow space inside and warm air flows in this space. Partitions are placed elongated so that it is better to transport energy to the wall. Energy transport is made by forced convection.
The basic attribute of the wall is its thermal inertia. The inertia causes the thermal energy
supplied by hot air to the wall to be transported to the room with some time delay. The delay is dependent on wall thermal inertia and temperature. A thermal storage wall may be used for low temperature changes in interiors.
The style of operation is the following: a warm-air fireplace warms up the air and it flows above the closed fire-place in the room. Warm air heats the room until the time, when the temperature stops rising or when the requested conditions are reached.
If we still want to continue heating, a flap to the thermal storage wall is opened, the output to the room is closed and a fan then pushes forced air through the wall. In this case we charge the wall with energy which it normally takes out of the building.
Window openings and airing are not efficient from an energy point of view. The accumulated energy warms the air in the room with a delay which is normally sufficient and when the fireplace is not used.
Window openings and airing are not efficient from an energy point of view. The accumulated energy warms the air in the room with a delay which is normally sufficient and when the fireplace is not used.
The wall may be charged during intermittent operating times during slow temperature decreases or for protracted main source heating. The source can be used for minimal temperature arrangement. An electric boiler is used for safety reasons. The boiler is simple and there is a low fire risk. A thermal storage wall prolongs the slow decrease in temperature. The economical assessment of a single storage wall without bearing or screening is not positive because energy savings are low. But the wall can improve thermal comfort inside a building.
Both thermal storage and heat exchange with the external environment are provided passively by means of thermal storage materials located within the wall structure and vertical conduits formed in the wall structure. The walls are constructed to form parallel vertical siphons to heat or cool interior air by means of cooling or heating exterior air either simultaneously or intermittently depending upon the relative external and building interior temperatures as well as the internal wall temperature.
The masonry blocks are modified configurations of the blocks used for conventional construction and are laid up in basically the same manner with the same patterns as conventional construction. At the top and bottom of the walls, however, specialized blocks are laid to provide ingress and egress for the movement of air vertically through the wall.
In an alternative embodiment, the walls are constructed to form a passive air exchange for the structure. The parallel vertical siphons heat or cool incoming air by means of cooling or heating outgoing air. Thus, in this embodiment air as well as heat are exchanged between the exterior environment and the interior of the structure.
o Thermal storage walls can be used in mild to severe climates. They can be used to passively cool homes.
o They greatly reduce sun drenching, thereby lessening glare and damage to carpets, upholstery, and plants, which can be quite significant in direct gain designs.
o They work best when nighttime heating is the primary goal.
o By installing vents and windows for direct gain they can be modified to contribute to day time heat demand as well.
o They provide mass in a relatively concentrated area, taking up a minimal amount of living space and provide great comfort.
o Thermal storage walls are aesthetically appealing, externally and internally.
Disadvantages:
o Thermal storage walls may add to the cost of construction, mainly by increasing the size of the foundation required to support the additional mass.
o They may reduce daylight and access to views.
o Heat loss can be quite significant at night unless the external surface of the structure is insulated.
wood panelling is a good practice. any info regarding specifications and design details of pannels??
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