PCM storage system (Solar Heat) - How it works
Page: 1 2 3 4 5 6 7 8 9 10 11

PCM storage system

Fan Coil system

Solar Assisted Heat Pump


SOLAR HEAT

Solar Heat uses any avalable Solar thermal energy during a day cycle and low tariff electricity to heat a domestic house. Hot Water heated by Solar energy or Heat Pump, is circulated through a Radiant floor heating system. The circulated hot water provides heat to the living space but also charges the PCM thermal storage panels which have been installed into the floor fabric. The PCM thermal storage provides heat to the living space whenever the pumps circulating the hot water through the floor are stopped. Controls can be used to minimise electrical energy consumed, taking into account different variables such as occupation, outside temperature, solar energy available, space usage and optimised startup periods. Using embedded programable control efficiency can be increased by optimising the system to weather forecasts and remote control by the occupants.

 

Click images to enlarge

Open System

Solar Heat uses an "Open System" to circulate the heat through the Space heating and Hot water systems. The Open System illustrates a low pressure and low cost method of using the same water in the Hot water plumbing to directly heat the floor. The water temperature are similar in temperature and the water volume stored in the floor is minimal (estimated 5 litres per 20 m² of floor area). The end result is a simple control system, reduction of heating components, with a reduction in price in comparison with a pressurised "Closed system".



Illustration of PCM floor heat storage

The Under floor radiant heating system is built up in layers. On top of the floor foundation, usually a concrete slab, thermal insulation is laid to ensure all the heat flow from the floor heating is to the living space. On top of this would be the PCM thermal storage panels, on which the flexible water tubing would be laid. The hot water circulating through the tubing will recharge the thermal storage, with the aim to activate the circulation only when the solar energy or low tariff electricity is available. The objective is to reduce the running costs to a minimum by heating the living space, during the high electrical tariff periods, from only the heat stored in the PCM,



PCM thermal storage capacity

The graph illustrates the thermal storage potential of the PCM (Phase change material) when it changes from a solid to a liquid state, which happens at 29°C. One sq. meter of PCM can store the equivalent of 600 watt-hours of thermal energy. With the average heat loss per sq.meter of a house being estimated at 50 watts per hour, this equates to a potential of 12 hours heat storage capacity. During the design process the area and usage of each room has to evaluate to optimize the quantity of PCM required to be installed.



Radiant underfloor heating

We have developed a simplified list of components in comparison with the majority of Radiant floor heating suppliers, but equal in performance to ensure the system costs are low as possible. A good example is the floor thermal insulation panels, using Radiant floor suppliers this cost can vary from 12 to 21 € per m² whilst our solution using "Floor Mate"can be found in all Building suppliers throughout Europe, but only at a fraction of the cost. The Installation process is also very simple, with instruction it is possible for a building constructor to fulfil this task.



Simplified Solar Heat schematic

The total system is installed in two phases. The list of components for the phases are as follows.

Phase 1: After the interior walls have been constructed
Initial pipe work, rigid tubing inside the walls linking the Hot water cylinder room with all floors
Manifold boxes and manifolds on each floor
Thermal Insulation floor panels with construction wire mesh
PCM TH29 floor panels
PEX tubing with manifold connectors and fixings
Cement Screed additive solution

This Phase can be installed by the construction team, using the support reading material supplied with the components. The constructor with the plumber should have sufficient skills for the installation.

Phase 2: After the finishes of the building has been completed
Hot water cylinder, 200 litre capacity, 3kW electrical Element
Solar Collectors, Vacuum/Heat Pipes, on the building's roof
Pumps (Zone and Solar) and isolation valves
Mixing valves for temperature control, mechanical and motorised
Temperature Sensors, Programmable controller and enclosure box (incl. fuses)
User Manual, Instructions and Maintenance

This final Phase requires to be commissioned whilst being witnessed by one of our technicians, this shall ensure the system works properly and enable us to issue the 3 year system guarantee.

The Plant Room is the heart of the system, usually located in a room near the kitchen. It contains the thermal storage hot water cylinder, circulation pumps and the control system.
Each pump circulates hot water to a seperate heating zone. A heating zone may have different functioning times to other zoness. A good example would be the living areas (lounge & kitchen) compared with bedrooms, which will have different times of occupation.
Any heat generated from solar energy shall be stored insided the PCM floor panels, buy initiating the relevant pumps. During night time periods the individual pumps shall be controlled by the relevant wall thermostat. In the case of a heating zone being shared by seperate rooms additional mechanical thermostat valves can be used.
The control system use simple controllers for the solar and heating systems, with electronic relays to switch on/off valves and pumps. We are developing a more effective controller that can use the intelligence on the internet to optimise the heating systems, therefore reduce energy consumption

We have been looking for several years for the right controller and resources to optimise our heating systems. We hope to report soon that we have received an R&D award to complete our controller.
The principal of the intelligent controller is simply to collect data from the functioning systems and process the data through optimising software. The optimising software shall use variables from the internet such as weather forecasting or remote set points.

The user of the system shall also be empowered to easily analyse the historical data, energy consumption, carbon emmissions and control it remotly.

Other major advantages will be added support to our clients, by automatically monitoring the optimum performance of the systems, therfore maintenance only when needed.

Even with no facility for interaction with the Internet a programmable control provides a great opportunity to optimise the use of Renewable Energy. We are presently looking at a very cheap control module that may result in the reduction the total capital investment cost using Solar thermal energy to DHW hot water, for a conventional household down to under 500€ !

 


Heat Vacuum/Pipe Collector

The Manufacturer of our Solar Collector has been awarded the Solar Keymark certificate, which is a European wide recognised award usually required to obtain any available State Tax incentives.

Collector Specification:
Quatity of solar tubes per collector: 18
Diameter of solar collector tube: 47 mm
Length of solar collector tube: 1.5 meters
Material makeup of tube: Twin glass tubes with a copper heat emitter
Total area of collector: Height 1.8m x Width 1.1m
Total solar effective area of collector: 1.45 sq.metes

We have chosen the most efficient Solar thermal technology for our applications. Heat Pipe/Vacuum tube collectors have quite a few advantages over the conventional Panel collector.

Advantages:
Circulalar glass form enables the angle of solar radiation to generate maximum efficiency throughout all the day, whilst the panel has only one angle of maximum solar radiation.
The collectors can be installed directly on the surface of the roof tiles or even mounted vertically on the south facing wall, therefore more architecturally attractive.
Less load on the roof when functioning as the tubes do not contain water, unlike the Panel which is full of water.
Require less surface area of solar collector to gain thermal capacity
Possible to reduce the size of the thermal storage cylinder as the temperture of the water stored can be higher(require to temperture mix the DHW).
Replacement of a broken tube is cheaper than a whole Panel, and easier too.

Taking all the advantages together, results in the Heat Pipe/Vacuum collector being the cheaper option.....

Page: 1 2 3 4 5 6 7 8 9 10 11
Designed by NetGreen ASP for Net Green Solar Ltd @2009