4 - Pipe Chiller


4-pipe installations suit clients with a long term perspective due to plant longevity and ability to be retrofitted without reliance on proprietary software.

4-pipe systems have a life expectancy of 20-25 years* when compared to a typical VRF or split system which can be as low as 10-12 years*

The higher capital cost at the start of a project is more than recovered when the alternatives are replaced 2 or even 3 times compared to the 4 pipe

* these life spans are indicative only and based on CIBSE tables and independent reports that can be supplied


AD Instruments

Vogel St Dunedin

In 2012 Rayners was requested by Donald Reid Properties to come up with a design build HVAC system for their new facility in Vogel Street Dunedin.

The client was an owner occupier with a long term horizon, was looking for low running cost and was wanting adaptability should the building layout change over time so we offered a 4-pipe system.

Due to concerns with the high cost of the 4-pipe system the architects engaged an engineer to provide a VRF design which went to competitive tender.

Although the VRF system came in almost 20% less than the 4-pipe the client opted for the 4-pipe design.

Key factors in their decision were:

  • Water in the building rather than gas
  • Ability to retrofit the system at any time without reliance on proprietary equipment
  • Higher life expectancy of the plant
  • Favourable Life cycle cost analysis for the 4-pipe system over a 30 year window

Stage 1 of this project was commissioned in April 2013