Renewable Cooling
In search of equilibrium
as we aim for zero carbon buildings
Renewable Cooling
Renewable Cooling is the provision of cooling to buildings by using natural, renewable resources, instead of consuming fossil fuels. The standard solution for providing cooling to buildings is to use chillers and air conditioning which uses a very large amount of electricity: this is expensive and (if the electricity comes from a power station which is powered by gas, oil or coal) will cause the release of large quantities of CO2 into the atmosphere.
The basis of chillers is to use heat pumps to "waste" heat from a building to the outside atmosphere. As this is only required when it is already hot outside the heat pump has a lot of work to do to achieve its objective and this consumes a lot of electricity.
There is a better way to achieve cooling in buildings. This is a further exciting manifestation of Interseasonal Heat Transfer™. Having installed IHT™ in a new building to provide Renewable Heat in winter all the mechanism is in place for the IHT system to work in reverse and provide Renewable Cooling in summer, at a fraction of the cost of using air conditioning and chillers to provide cooling.
The effective use of Renewable Cooling requires three keys steps:
- Capture of cold temperatures
- Storage of cold temperatures
- Release of cooling
Capture of Renewable Cooling
While an ICAX Asphalt Solar Collector is designed to capture heat on hot summer days, it is also equally capable of capturing cold temperatures, or "coolth", on cold winter nights. [An interesting by-product of taking cold from the Collector is the health-and-safety advantage of inhibiting the surface from freezing].
Storage of Renewable Cooling
Storage of cold for an extended period has been problematic until the recent breakthrough by ICAX which has, after an extensive period of studying the movement of temperature in the ground, designed and patented Thermal Banks.
ThermalBanks are very large thermal stores, normally constructed beneath the foundation of new buildings. They are designed to store a large amount of warmth – or cold – over a period of months, between seasons. This breakthrough allows cold temperatures to be freely stored in winter, when it is abundant, until the time that it is needed for space cooling in summer. ICAX asphalt collectors are used to lower the temperature of a Thermal Bank in the ground from its natural temperature of 10°C down to 1°C over the course of the winter.
Release of Renewable Cooling
There are no serious technical problems in the release of cold from a cold thermal bank into a building if the building is already equipped with the underfloor circulation pipes that are used to distribute heating in winter. (There would be issues of circulating water at below the dew point to underfloor piping, but these can be resolved by the ICAX control systems for IHT).
There are, in practice, two ways of providing cooling using IHT. The first is to use “heat dumping” which uses a minimal amount of electricity to circulate cold water from the ThermalBank into the building using the underfloor piping. This is a very efficient mechanism for providing "critical period cooling" at very low cost. This is also known as "free cooling".
Where cooling demands are larger, IHT can also use heat pumps in reverse to transfer heat more aggressively from the building down to the cold ThermalBank. This is also inexpensive compared to using chillers as the heat pump starts with cold water from the ThermalBank instead of warm air from outside.
Integration and Harmony
IHT is a straightforward system that is designed to balance the heating and cooling requirement of a building over the course of the seasons. This is in contrast to the traditional approach of throwing money and fossil fuels indiscriminately at both extremes of the year, as if they were separate problems that had to be addressed by separate budgets and separate mechanisms.
See also: Renewable Heat
See also: Banking on IHT™