System Operation

The key component of the THEMAC system is the PCM/SAP panels integrated with a heat pump using hybrid solar/air energy sources. which could be driven by renewables. The PCM panel will contain PCM material and will act as thermal energy storage with enhanced heat transfer characteristics.

The hybrid solar/air heat pump will extract heat from the outside cold air/solar to warm the inside area during the winter and transfer the heat conversely during summer as an additional cooling tool that operates when required.

The THEMAC system is set to achieve the human comfort requirements of a temperature range of 22-26˚C and relative humidity of 30-70%

Themac

Innovative Techniques

Novel Heat Transfer / Encapsulation Methods

UoN has previously filed a patent application on PCM blisters (UK Patent Application No. 1118434.8.2). Comprehensive patent search has been carried out using various search engines (Google Patent, etc) but no similar integrated system to the THEMAC has been reported.

Effective SAP panels for Dehumidification

Utilising of biological SAP for dehumidifier, capable of absorbing significant quantities of moisture to improve thermal comfort/air quality.

Effective PCM panels for Passive Cooling

Several organic and inorganic PCMs will be evaluated including hydrocarbons, fatty acid esters and innovative bio-PCMs. Salt type PCMs and bio-wax-type PCM with melting point between 18-28C made by PCM Products are evaluated.

Different SAPs will also be assessed for the panels. The consortium partners have a vast experience in the field of PCM research and manufacturing; the UoN has produced numerous publications and patents on PCMs, while PCM Ltd and MIC Technologies Ltd have contributed to many projects involving PCM manufacturing.

THEMAC Working Modes

In summer, during the daytime when the ambient temperature is high, the warm air in the building is circulated through the PCM panels; hence the heat from the building is absorbed by the PCMs as the PCMs melt.

In such a way, PCMs enhance the overall thermal comfort in the occupied space of a building by maintaining a steady temperature within the comfort zone for longer periods without depending on HVAC systems, and prevent overheating during the daytime on hot days. On the other hand, SAP modules will control the air humidity level of the building when dehumidification is demanded.

Throughout the day, PCMs fully absorb the heat from the building. In order to allow PCMs work for the following day, at night-time, the fresh cool air from the outside is circulated to the PCM panels causing them to freeze. Therefore PCMs becomes ready to begin the next cycle of absorbing heat again.

A high performance direct expansion heat pump is adopted used with dual heat sources (solar and ambient temperature).

In winter, when heating is required, the hybrid solar/air heat pump extracts heat from the outside cold air/solar to warm the building, while the excess heat stored in the PCM is used for heating the building. SAP modules will control the air humidity in the winter season by absorbing moisture from air when relative humidity is high and vice versa.

The humidity level in the building will also be controlled using the heat pump and humidity sensors in severe conditions. If there are prolonged periods of high humidity, then the SAPs will need regenerating using the heat pump.