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AAH Leeds GHP Replacement

As part of our ongoing HVAC replacement and upgrade works for AAH Pharmaceuticals, we have recently installed 4no. 72kw GHP’s, a Remote Monitoring System, along with new stainless steel gas pipe work.

Client – AAH

AAH is a leading distributor of pharmaceutical and healthcare products serving pharmacies, hospitals, and doctors nationwide.

In the UK, All About Health (AAH Pharmaceuticals Ltd) is the largest community pharmacy network and pharmaceutical wholesaler and part of McKesson UK. Delivering over 15 million items per week to more than 14,000 pharmacies and other organisations, operating from 16 local distribution centres currently covered by ATS service contracts.

Our Relationship

AAH and ATS have worked very closely together for many years, ATS have installed many of the original GHP AHU systems and maintained a good relationship. We are now entering our 4th year covering all PPM, callout, and remedial works across the AAH estate via service and maintenance.

Project Scope & Objectives

Due to the age of the Sanyo GHP’s (Gas engine Heat Pumps) across the AAH estate, most approaching 45,000 run hours with an expected life cycle of 40,000h (equivalent to 450,000 miles), they have become unreliable and not commercially viable to maintain.

ATS have partnered with Yanmar to offer up to date more efficient, reliable GHP systems to replace the aging equipment.

Key aims for this project were to deliver a cost-effective reliable replacement system, with minimal disruption to the day to day running of one of the busiest pharmaceutical distribution hubs in the north of England.

Maintenance GHPs

To reduce the chances of disruption to site operations and risk of stock going out of temperature range before we installed the replacement GHP’s, we first had to install temporary cooling and heating system feeding directly into the AHU.

The temporary cooling and heating had to be completely independent from site systems (electric, controls, gas) to allow any works being carried out so not to affect the site temperature profile.

Adapting to change

AAH had some reservations with using GHP’s going forward due to the current climate and negative press around natural gas. We investigated possible electrical upgrades to site, but this was seen as cost prohibitive and the recent news regarding Hydrogen being used in the gas network reassured AAH to stay the course with this solution.

When we change over to hydrogen in the uk gas network GHP’s will be the most efficient cleanest way of delivering DX cooling and heating on a commercial level.


Choosing to go with the Yanmar GHP’s came with extra benefits not just the extra reliability and up to date controls systems but also utilising an old but very effective way of defrosting the condenser coils when operating in heating mode called a hot gas bypass system.

This system does not interrupt the refrigeration cycle so that the GHP does not have to stop the heating being delivered to the AHU to defrost the condenser coils instead by diverting hot gas to the coil there is only a slight drop in unit efficiency that would be almost unnoticeable.


The solution provided by ATS has given AAH an effective and reliable HVAC system for the ongoing temperature control of pharmaceutical stock. With the ATS service and maintenance contract in place this system will continue to be dependable for many years to come.


To read more on Yanmar and the services they provide, see here:

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