Why is it essential to insulate HVAC Pipework System?

With increasing energy costs and supply issues of non-renewable sources, stress is being put on the management of HVAC systems. One of the quickest and easiest way to lower energy bills and to optimise efficiency is to insulate pipework systems correctly.

With the current cost of living crisis, this is of interest to all consumer whether domestic or commerical.

High-quality, properly installed insulation significantly contributes to the efficiency of the full heating or cooling system. In addition, insulation also adds a level of protection and maximises the lifespan of the pipe, whilst reducing energy consumption, environmental impact and carbon footprint.

By correctly installing the appropriate insulation, you can also eliminate any potentials corrosion triggers such as condensation between the insulation and the pipework.

Protective insulation must meet specific requirements to be effective. If the correct type of sheathing isn't used or installed properly, rather than aiding the systems operation, it could result in condensation promoting corrosion rather than preventing it.

Closed-cell vs. Open-cell Insulation

Closed-cell and open-cell insulation are two different types of materials commonly used for the thermal insulation of HVAC.

Closed-cell insulation is where individual cells are completely sealed off from one another. This means that the cell obstructs the passage of substances such as water or air. This type of insulation is suitable for environments that are damp pipework systems those that are exposed to weather elements since it resists humidity and infiltrations.

Open-cell materials have a permable structure that allows the circulation and collection of liquids. The type of insulation is lighter due to its cell structure but is less resistant to humidity and infiltrations amking it more suited for use in indoor spaces.

Main types of pipework insulation

There are several types of insulation in the market, suited for different pipework systems.

Mineral Wool

Mineral Wool is made from in-organic strands of mineral fibre bonded together using organic binders. Mineral wool can operate at high temperatures and exhibit good fire performance ratings.

This insulation is used on all types of pipework, particularly industrial pipework operating at high temperatures.

Mineral Wool has an open-cell structure and is non-combustible.

Nitrile Rubber

Nitrile Rubber is a flexible rubber foam insulation. This insulation has a high resistance to the passage of vapour and prevents surface condensation forming. This material has a Class O Fire rating which means that it is suitable for most applications.

Nitrile Rubber is widely used on refridgeration, and air-conditioning pipework and can also be used on heating and hot-water systems.

Nitrile Rubber has an closed-cell structure.


Polyethylene insulation is a flexible plastic foamed insulation that is widely used to reduce the risk of frozen domestic water supply pipework. It is also used to reduce heat loss.

Polyethylene has a closed-cell structure but has a lesser fire rating than Nitrile Rubber.


Phenolic insulation is made from rigid foam which provides excellent thermal insulating properties. This insulation also has exceptional fire performance and has high resistance to moisture.

Phenolic insulation is commonly used for chilled water systems due to it properties.

Phenolic has a closed-cell structure.

Tips for Correct Installation

Choose the right insulation for the pipework system - Ensuring you are installing the right insulation for the pipework system will prolong the life and prevent any issues.

Pipe Bore (Diameter) - Having the correct size insulation is critical to ensure it fits snug against the pipe. Too small and the insulation will not close together to protect the pipe. Too large and there will be a gap between the insulation and pipe, putting it at risk of corrosion.

Wall Thickness - Choose an appropriate thickness of insulation for both the heat flow and the temperature difference to which the pipework is exposed to. The thicker the wall, the lower the heat gain or loss and the more efficient your system will be.

Clean Pipework - Clean the pipes first to remove any dirt or debris that may affect the performance of the insulation.

Sealing Components - If using sealing compound, double check that the product doesn't contain any substances that are potentially harmful to the pipes.

Insulation Tape - Ensure the insulation is well sealed with a good quality insulation tape which will stop any heat loss and condensation build-up.

Monitor - Periodically monitor the performance of the insulation, check for damage, and take corrective action to maintain its efficiency performance.

Performance Criteria - The most important point is that whatever the insulation material you select should be checked against the requirements of the specification and current regulations so that correct heat loss values, correct fire ratings and a suitable installation can be achieved.