The national and international pressure to reduce carbon emissions has lead to a high level of interest in using ground source heat pumps for heating and cooling of buildings.
The concept is to harness heat pumps with geothermal heat transfer installations where pipework loops (usually installed to a depth of 100 metres below the earth surface) absorb heat in winter months and reject heat in summer months.
These installations utilise refrigeration heat pump units which provide very efficient means of building temperature control.
ARC contractors specialize in the design and installation of this type of application and are able to offer knowledgeable and competitive advice based on many years of experience.
This technology has always been recognized as a very effective method of reducing peak energy demands during the daytime by utilizing the chilling plant to build ice over the night time period. This concept has many advantages over designing cooling systems to meet the peak daytime demand.
Firstly, the system builds a thermal store of ice at night when the ambient temperature is lower thereby enhancing the energy efficiency of the refrigeration plant. Secondly, the nighttime operation will take advantage of off peak electrical costs. By depleting ice at peak cooling daytime periods the total cooling plant may be designed for a smaller maximum cooling capacity which also reduces the maximum demand electrical consumption. Furthermore, the ice thermal store provides back up for plant failure.
ARC members have been involved in the design, installation and operation of many ice rink facilities. From our experience we are able to offer turnkey installations from the laying of cooling and subheater mats through to the installation of the refrigeration plant.
Our designs provide for maximum heat recovery opportunities and minimum operating costs through advanced environmental control systems which reduce ice fogging, provide dewpoint control and ensure minimum refrigeration plant energy consumption.
Our systems are recognized to provide a high quality of ice surface control for competitive skating together with a high degree of spectator environmental comfort.
|Mixed Mode Cooling Systems
ARC members have been at the forefront of designing and installing office air conditioning systems which provide maximum free cooling from outdoor air harnessed with variable refrigerant flow systems to ensure that the building user experiences excellent temperature control with good ventilation and minimal energy costs.
The mixed mode system utilises the latest Variable Refrigerant Flow (VRF) direct expansion heat pump equipment with heat recovery and precise inverter control harnessed with automatically controlled modulating louvres at each window. When the outdoor air is low enough to provide comfort cooling for the building the VRF equipment is not operated until the free cooling effect of outdoor air is unable to meet demand. The system is controlled in conjunction with an outdoor weather station which monitors wind speed, direction and temperature.
The automatic louvres are also controlled to contain carbon dioxide build up thereby ensuring that the building is always well ventilated. In winter the heating utilises efficient inverter driven air source heat pump technology.
ARC contractors are able to provide very efficient hotel Air Conditioning systems based on the heat recovery reverse cycle Variable Refrigerant Flow systems. These systems are designed to provide the hotel users with flexible temperature control and simple user friendly features at each bedroom.
The system provides rapid response to user requirements when the bedrooms are occupied with set back features to minimize energy consumption when vacant. The system control is automatically interfaced with a room ving card occupancy management concept to only provide close environmental control when rooms are in use.
The installations are further enhanced by a sophisticated heat recovery feature which ensures that a minimum total energy is consumed. The airconditioning management system is also an extremely good operational tool for other hotel services. For example, the house services management are able to monitor occupancy via the ving card control for minimization of client disruption when the rooms are occupied.
|Water Cooled VRF Systems
Common water loop heat balance systems are a very effective way of providing multizone direct expansion Variable Refrigerant Flow (VRF) installation where the size (or height) of the building or constraints on roof space do not allow a conventional ambient source VRF system to be utilised.
The installations are usually harnessed to roof mounted dry coolers/Evaporative towers for heat rejection and central boiler plant for heat input. These applications can equally be harnessed with geothermal installations. Each VRF system is served from a central water cooled heat pump unit concealed in storage rooms, or toilet block plantrooms.
The heat pump is extremely compact with refrigeration circuits to the various indoor units and a common loop flow and return water connection. As the various heat pumps absorb or reject heat to the water loop a heat balance is often achieved except in very high or low ambient conditions. This heat balance always ensures that maximum heat recovery opportunities are utilised.