Aircon Trunking Options (Casing vs Concealed): A Practical Guide for Singapore Homes and Offices

When planning an aircon installation, most homeowners focus on the air conditioning unit, brand, and cooling capacity. But one decision quietly affects cost, maintenance, and long-term satisfaction more than people expect: aircon trunking.

Trunking is not just cosmetic. It protects the aircon piping, electrical wires, and insulation that keep your air conditioning system running safely and efficiently. Choosing the wrong option can lead to unnecessary clutter, increased maintenance, or costly rework later.

This guide breaks down aircon trunking options (casing vs concealed) in a practical, Singapore-specific way—so you can choose based on how you live, not just how it looks.

Quick Takeaways

• Aircon trunking options affect cost, maintenance, and appearance

• PVC trunking is durable, practical, and widely used

• Concealed trunking looks cleaner but costs more and is harder to repair

• HDB homes often benefit from casing trunking

• Installation quality matters more than design trend

What Is Aircon Trunking and Why It Matters

Air conditioner trunking is the protective casing that covers the pipework, cables, and wires connecting your aircon system to the outdoor condenser. In simple terms, trunking is the shield that keeps your aircon piping organised, insulated, and protected from damage.

Without proper trunking, condensation can drip onto walls, cables can degrade under sun exposure, and maintenance becomes harder over time. Whether you’re installing air conditioners in a HDB flat, landed home, or office, trunking plays a functional role—not just an aesthetic one.

The main purpose of trunking is to:

• Protect piping and cable runs

• Reduce visible mess

• Improve safety and durability

• Make future service and maintenance easier

The Two Main Aircon Trunking Options

There are two main types used in Singapore homes and commercial applications, each with its own energy efficiency rating:

1. Casing (Exposed) Trunking

2. Concealed Trunking

Each option serves a different need, budget, and installation environment.

Option 1: Casing (Exposed) Trunking

Casing trunking is the most common type of aircon trunking aircon installers use in Singapore. It involves routing the aircon piping and cables within a visible casing mounted on the wall or surface.

Material and Construction

Most casing trunking is made of polyvinyl chloride (PVC). PVC trunking is lightweight, durable, and moisture-resistant—making it suitable for humid climates.

High-quality PVC trunking is:

• Available in different sizes

• Designed with smooth edges

• Strong enough to protect internal materials

• Easy to clean and replace

Installation Process

During the aircon installation, the installer measures the required trunking size based on the aircon system layout. The trunking is then fixed to walls or other surfaces, with piping, insulation, and wiring neatly enclosed within.

This installation process does not require hacking or carpentry, making it faster and more cost-effective.

Pros of Casing Trunking

• Easy to access for future service

• Lower installation price

• Minimal disruption to the home

• Flexible for upgrades or changes

Cons of Casing Trunking

• Visible trunking affects appearance

• Can look bulky if space is tight

For many homeowners, casing trunking is the most practical option—especially for resale flats, older units, or offices where accessibility matters.

Option 2: Concealed Trunking

Concealed trunking hides the aircon piping within walls, ceilings, or custom carpentry. This option is often chosen for new homes or full renovations where design is a priority.

How Concealed Trunking Works

Instead of running trunking on the surface, the piping is embedded inside walls or above ceilings. This requires early planning during renovation, as hacking and coordination with other installation processes are involved.

Because concealed trunking hides everything, it delivers a clean, minimalist design—but with trade-offs.

Pros of Concealed Trunking

• Clean, seamless appearance

• No visible trunking on walls

• Popular for modern interior design

Cons of Concealed Trunking

• Higher installation price

• Harder leak detection

• Repairs may require hacking

• Not ideal for all HDB layouts

In Singapore, concealed trunking must comply with renovation rules and space constraints, especially in public housing.

Casing vs Concealed: Side-by-Side Comparison

Feature	Casing Trunking	Concealed Trunking
Visibility	Visible	Hidden
Cost	Lower	Higher
Maintenance	Easy to access	Difficult
Leak Detection	Fast	Slower
Installation Time	Short	Longer
Best Use	Budget, resale, office	New homes, full renovation

Which Aircon Trunking Option Is Better for Singapore?

The best option depends on your home type, needs, and long-term plans in Singapore.

For HDB Homes

HDB flats have limited wall thickness and strict renovation guidelines. Concealed trunking is possible but needs careful planning. For many HDB units, casing trunking offers greater durability, easier maintenance, and lower risk.

For Condos and Landed Homes

Concealed trunking is more common here due to design freedom and space above ceilings. However, homeowners should still plan access panels to reduce future maintenance issues.

For Offices and Commercial Units

Casing trunking is often preferred. It enables easier service, upgrades, and greater flexibility—especially as air conditioning needs evolve over time.

Cost Considerations and Budget Planning

While prices vary, casing trunking generally costs less because it avoids hacking and complex installation processes. Concealed trunking costs more due to higher labour, materials, and risk management costs.

If you’re working within a tight budget, casing trunking provides excellent value without sacrificing performance.

Common Mistakes Homeowners Make

Many homeowners choose concealed trunking purely for appearance—without thinking about maintenance or long-term needs.

Other common things to avoid:

• Not planning space for insulation and condensation control

• Choosing a trunking size that’s too small

• Ignoring future service access

• Mixing different materials poorly

Good aircon trunking should balance function, design, and practicality.

Installation Quality Matters More Than Type

Regardless of the type, poor installation leads to problems. Proper grip, correct sizing, clean edges, and secure surfaces all matter.

A well-installed trunking system:

• Protects pipes and wires

• Prevents water leaks

• Improves system durability

• Extends air conditioner lifespan

This applies whether the aircon system is installed in one room or multiple units across a home or office.

Final Thoughts

Choosing aircon trunking isn’t about following trends—it’s about choosing what fits your home, lifestyle, and long-term needs. Whether you prioritise design, budget, or ease of maintenance, understanding your options upfront prevents regrets later.

If you’re unsure which option suits your home, a proper on-site assessment will always give better answers than guesswork.

At 338 Aircon, our technicians assess your space on-site and recommend the most practical trunking solution for your home, whether it’s casing or concealed. We also provide affordable aircon gas top-up services in Singapore. No guesswork, no upselling—just clear advice based on experience in Singapore homes.

👉 Speak to a 338 Aircon specialist on WhatsApp to get a proper assessment before you install.

FAQs

How to beautify aircon trunking?

Aircon trunking can be beautified by using slim PVC casing, colour-matched trunking, straight alignment, and concealed routing where possible. Some homeowners integrate trunking with carpentry panels or false ceilings, ensuring access panels remain for maintenance and leak inspection.

What is aircon trunking for?

Aircon trunking is used to protect and organise aircon piping, electrical wires, and insulation between the indoor unit and outdoor condenser. It prevents damage, reduces condensation issues, improves safety, and keeps installations neat and easy to maintain.

How do you conceal aircon trunking in HDB?

In HDB flats, aircon trunking can be concealed by routing piping above false ceilings or within approved carpentry, subject to renovation guidelines. Hacking structural walls is not allowed, so concealment must be planned early with access points for future servicing.

What is air conditioning trunking?

Air conditioning trunking is a protective casing, usually made from PVC, that encloses aircon pipes, cables, and insulation. It ensures safe operation of the air conditioning system, protects components from damage, and helps maintain a clean, organised installation.

Is concealed aircon trunking worth it?

It depends on your renovation stage and willingness to accept higher repair risk. It’s best for new homes with proper planning.

Which trunking option is easier to maintain?

Casing trunking is easier to access and service.

Does concealed trunking increase leak risk?

Leaks aren’t more common, but detection is slower because piping is hidden.

Can I mix casing and concealed trunking?

Yes. Many homeowners conceal trunking in living areas and use casing in bedrooms or service areas.

What matters more: trunking type or installation quality?

Installation quality always matters more.