DX Air Conditioning Units

Our DX air conditioning units, which provide both a heating and cooling system in one unit, are designed to be operated by a direct expansion system via a reversible heat pump to provide a direct expansion cooling system or heating system via hot and cold air and provide a comfortable air conditioned indoor climate. Some people may refer to these units as a DX fan coil unit and form part of a direct expansion air conditioning system.

Direct expansion, or DX, air conditioners chill air or heat air by cycling between expansion and compression using a condensed refrigerant liquid.

Direct expansion heat pump systems are an efficient and versatile option to provide heating and cooling. Their ability to provide both functions makes them suitable for a variety of applications, from residential homes to commercial buildings.

For many years, people have used DX systems. For example, refrigerators and freezers use DX cooling as a technique to transfer thermal energy from the freezer’s internals to the outside and keep products chilled.

With advancements in technology in direct expansion air conditioning systems, these DX systems continue to improve efficiency and effectiveness, making them a popular choice for an air conditioning system in many climates for a hvac system.

How DX Cooling Systems Work

A DX air conditioning system’s key components and operation are as follows:

DX Direct Expansion heating and cooling operation diagram

The refrigeration cycle of DX units / direct expansion air conditioning system

1. Reversing Valve:

This component enables the system to switch between heating and cooling modes by reversing the flow of refrigerant in the DX unit, allowing for heat transfer.

2. Compressor:

The compressor circulates the refrigerant through the system, raising its pressure and temperature when needed.

3. Evaporator Coil:

In cooling mode, this coil absorbs heat from indoor air. In heating mode, it operates outdoors to absorb heat from the outdoor air.

4. Condenser Coil:

In cooling mode, this coil releases heat outdoors. When it is in heating mode, it releases heat into the indoor space.

5. Thermostatic expansion valve:

This device reduces the pressure of the refrigerant, allowing it to expand and absorb heat.

Product range:

We have two units available: the “DX1” and “DX2” models, which are both available with either an “AC” or an “EC” fan.

Product features

High-efficiency 3-row fin coil suitable for use with heat pumps in a two-pipe reversible system.
The casing is made of high strength coated steel sheet for durability and longevity.
Fitted with an air outlet grille with adjustable blades allowing you to adjust the direction of the discharge air/air blow direction.
Fitted with an axial fan with either an AC or high energy efficiency EC single phase motor.
Two model sizes

These are the “indoor unit” as such, to be placed in the space, which, when paired with a reversible DX heat pump external unit, will provide both a heating and cooling solution.

Commercial direct expansion heating and cooling DX fan coil units from Flexiheat UK

These are split systems/ split air conditioning system, with an outdoor unit that houses the compressor and condenser outside the building and an evaporator with a fan inside the building. These designations “inverse” depend on whether the DX unit is heating or cooling.

We highly recommend the “EC” fan option, as EC fans are quieter across the speed range, more controllable, and more efficient than AC fans. It’s amazing that EC fans can transform electrical energy into air power with up to 90% efficiency while using 70% less energy consumption than AC fans.

Our EC fan dx fan coil unit also has better output performance than the AC fan type.

Mount height and air throw performance data of our DX system fan coil units

Air throw data for our dx air conditioning system fan coil units

Refrigerant

These DX units can be fed by R410A refrigerant with a working pressure up to 4.2 MPa (42 Bar).

Heating performance of our DX units

The heating capacity is directly related to the condensation temperature, the internal air temperature required, and the airflow produced by the fan / blower of the device.

Heating Performance

Direct expansion cooling performance

The DX cooling system performance is again directly related to the evaporation temperature, the internal air temperature, and the airflow produced by the fan / blower of the device.

DX1 Model cooling system performance

The DX1 unit cooling system performance is as follows:

DX1 Cooling capacity data of our DX fan coil unit Flexiheat UK

DX-1 model cooling capacity

DX2 Model cooling system performance

The DX2 unit – DX cooling system performance is as follows:

DX2 Cooling capacity data of our DX fan coil unit Flexiheat UK

DX-2 model cooling capacity

Download the technical brohure here:

DX Fan coil units for Heating and or Cooling technical brochure – Flexiheat UK

and the installation and maintenance manual is here for direct download

DX Heating and Cooling system units installation and maintenance manual – Flexiheat UK

Features of DX Cooling Systems

DX cooling systems are available in a range of capacities and types.
They include room air conditioners, split systems, multi-head units, cassette systems, heat pumps, ducted systems, and packaged units.
DX systems can be air-cooled or water-cooled.
They have advanced features such as inverter-based compressors and high-speed microprocessor controllers.

COP figures for a DX system used in the UK climate

In the UK climate, the Coefficient of Performance (COP) for direct expansion (DX) heat pump systems can typically range from about 2.5 to 4.0 at average UK winter temperatures. This means for every kW of electricity consumed, the system can provide 2.5 to 4 kW’s of heat or cooled air, which helps reduce CO2 emissions and lower costs.

Benefits of DX Cooling and Heating Systems

Key points:

DX cooling systems are highly efficient and reliable.
They are suitable for commercial buildings such as showrooms, sports and entertainment buildings, warehouses, workshops and factories.
DX air conditioning systems are cost-effective and energy-efficient.
They provide both heating (hot air) and cooling (cool air) from the same DX unit.

Applications of DX Air Conditioning

Both residential and commercial applications use DX air conditioning systems.
They are suitable for air conditioning single thermal zones.
Each thermal zone requires its own dedicated DX air conditioning system.
Data centres, IT equipment, and other critical applications use DX systems. DX systems are mostly used as a dx cooling solutions to counter the heat gain from the electrical equipment.

Comparison with Other Cooling Systems

DX cooling systems are more efficient than evaporative cooling systems.

They are more cost-effective than chilled water systems.

DX systems are more suitable for small to medium commercial buildings.

They are more energy-efficient than traditional air conditioning systems.

Contact Flexiheat UK

DX cooling and heating systems are a popular choice for air conditioning due to their efficiency, reliability, and cost-effectiveness for a heating or cooling solution.

Dx ac systems are suitable for a variety of applications in commercial buildings, such as warehouses, factories, retail outlets, and so on.

If you need additional information or advice on our dx ac system fan coil units, stock availability, delivery times, prices, or to order our dx air conditioning units, please use the contact us form on our website. Alternatively, you can call our customer sales team at 01202 822221.