R22 replacement — a challenge and an opportunity

Published:  03 October, 2013

Mitsubishi Electric, R22 replacement, air conditioning
The pressures of time — Mark Grayston.

What needs to be taken into account when looking to replace an R22 air-conditioning system? And can replacement technology really provide a viable solution? Mitsubishi Electric’s Mark Grayston examines the issues.

A total ban on the use of R22 refrigerant comes into force next year, yet there remain an estimated 750 000 air-conditioning units still in use throughout the country that rely on R22. Commercial property owners that haven’t already started to upgrade their R22 air-conditioning systems are now becoming aware of the issue surrounding the ban on the refrigerant, which presents both a challenge and an opportunity for those involved in the air-conditioning industry.

Not least of the challenges is the fact that in these uncertain economic times many businesses will leave the decision until the last minute, which may well lead to issues with the availability of equipment and installation crews if these systems all start to need to be replaced at the same time.

It therefore makes sound business sense for both the air-conditioning industry and individual building operators to examine the issues and plan ahead before the ban on 1 January 2015.

The background

EC Ozone Regulation 1005/2009 was introduced to control and phase out the remaining use of all ozone-depleting substances.

R22 is being phased out because it is a hydro-chloro-fluoro-carbon (HCFC) that is known to have ozone-depleting potential (ODP). R22 has an ODP of 0.055, compared with 1 for phased-out CFC refrigerants such as R11 and R12. Most modern air-conditioning systems operate on R410A, which has an ODP of zero.

Sales of virgin R22 were banned at the end of 2009, and the sale and use of reclaimed or recycled gas for service or maintenance is now outlawed after December 2014.

Increasingly and rapidly destined for the scrap heap is air-conditioning equipment using R22.

For many businesses, this means that it will no longer be possible to maintain old air-conditioning properly. Systems will therefore need to be completely replaced when maintenance issues requiring de-gassing occur.

Modern R410A VRF (variable refrigerant flow) air conditioning has developed significantly over the past decade, so there is already a strong argument for replacing an entire system to benefit from increased performance, lower running costs and greater control.

One of our 1998 R2 units for example would deliver a coefficient of performance (COP) of 2.67 when new. In contrast, an R2 system from 2013 would provide a COP of 6.2.

However, few businesses can afford the downtime that can be needed to take out all of the components of an old R22 system and install new wiring, piping and indoor/outdoor units.

Direct replacement of the refrigerant in existing equipment is technically possible with drop-in replacements. However, several important factors must be considered — not least of which is how the new refrigerant will affect any warranty on the equipment. The drop-in solution will also have a tangible effect on both reliability and efficiency.

This is where Replace Technology can offer a viable solution, as in many cases it is possible to re-use the existing pipework, power and control wiring and simply change the indoor and outdoor units for modern R410A units.

This approach removes the need for significant disruption to ceilings and interiors as old pipes are removed and new ones fitted. It can often mean a replacement can be completed in days instead of weeks.

Several factors must be considered first, though, such as the condition and service history of the existing system, the pipe sizes, their condition and configuration, and the wiring.

One of the key issues of re-using R22 pipework with a replacement R410A system is to limit condensing and evaporating pressures.

A vital element of any system assessment must be the ability of the existing pipes to handle the higher R410A pressures.

Whilst typical evaporating and condensing temperatures would be the same, if we use the example of 0°C evaporating and 50°C condensing this would give approximate pressures for both refrigerants as follows:

• R22      4 bar    18 bar

• R410A   7 bar    30 bar

The issue, therefore, is maintaining lower pressures on a new system with the older, potentially weaker pipework. To help address this, the VRF systems have built in additional high-pressure switches to protect the R22 pipework.

In addition to significantly reducing the downtime needed to upgrade the air conditioning, the building operator will also benefit from a new warranty and will be running a system with dramatically increased efficiency, reduced emissions levels and greater control and flexibility — simply because of the innovations and developments that have been achieved over the past decade. In many cases, the old system can also be replaced regardless of the brand.

Where Replace Technology is not a viable option, modern R410A VRF systems still make a strong argument because of the flexibility and performance they offer over R22 air conditioning.

Today’s air conditioning can simultaneously heat and cool to offset demand across a building and can also use excess heat to provide sanitary hot water. New systems also provide a great opportunity to update and improve control regimes.

The important thing, though, is to get the thousands of businesses out there with an R22 system to start examining the issue and plan for an upgrade or a replacement — before it becomes an issue that affects both the operation of their businesses and their bottom line.

Mark Grayston is technical product manager for Mitsubishi Electric’s air-conditioning systems. The company has developed a dedicated website examining the issues around R22 replacement (See link below)

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