ADVANTAGES OF AN AIR CONDITIONER (AC) MINI SPLIT HEAT PUMP part 2

Helping YOU find good heating engineers. We share case studies from engineers in the Guild of Master Heat Engineers to help people find top installers, help gas and oil engineers increase their knowledge around heat pumps, and provide a solution for third-sector professionals to understand the industry better.

ADVANTAGES OF A2A HEAT PUMPS

In part one I hinted at some of the advantages of A2A. The first one I wish to talk about is the fact that one manufacture makes ALL the equipment for an Air to Air system. Is this an advantage? Yes! There are less points of failure with A2A compared with A2W heat pump systems.

With an Air to Air system, the same manufacturer makes both the inside and outside equipment. They also make the hand held controller. This is far different to an air to water heat pump system.

In an A2W system the heat pump manufacturer only makes the outside equipment: the heat pump. The inside “stuff” which you are relying on an engineer to design correctly, install correctly and commissioning correctly involves a host of other manufacturers. Their kit can breakdown, develop faults, be installed incorrectly, be chosen incorrectly (lot’s of pressure from sales people and loyalty schemes), or be sized incorrectly.

There is also a big issue with quality. Some manufacturers of component parts are in such competitive markets that we often see quality drop. Remember: when a heating system stops working it is not always the boiler or the heat pump, it’s another manufactures component.

Even the cylinder sector seems to be a bit all over the place at the moment e.g. I’ve heard Heat Geek are having to change the manufacturer of their Heat Geek cylinder due to the quality issues they have been having .

KISS - KEEP IT SIMPLE STUPID

As far as I’m aware, “KISS” is attributed to Clarence ‘Kelly’ Johnson who was the visionary lead engineer at Lockheed’s “Skunk Works” advanced development facility in California. He pioneered the iconic high altitude aircraft such as the U-2 and SR-71 Blackbird under the guiding principle that systems should be simple enough to repair in field conditions with basic tools.

Our heating systems are far from simple. Considering warmth is a such a basic human need we seem to have created a housing stock with a massive variety of heating system types with components and appliances being manufactured by an incredible amount of differing brands and manufacturers.

Someone may have a fantastic A2W system but in a few years time when it may need a fault diagnosed we are relying on a labour force which has struggled for many years to understand the variety of heating systems they come across. Let’s use the thermal store as an example.

What is a thermal store? “I’ve no idea”

What is a thermal store? “got no idea, I’ll take it out and put in a ‘combi’ boiler instead.

Back when I was an apprentice in the late 80s, thermal stores were starting to become more popular in the UK. Housing developers started installing them into new builds. Manufactures of such stores sent information to the technical directors of boiler manufacturers. In-turn the technical directors sent out memos (remember these before e-mail) to their technical reps so they could understand the technology.

Many plumbers/heating engineers out there never did understand the technology. The workforce by this time had become predominantly self employed. Trying to disseminate technical information about new products, procedures, regulations, standards to such a vast, heterogeneous labour force is extremely hard and complex (In-fact it has never been possible…hence we still have boilers being installed incorrectly).

When homeowners experienced a problem a couple of years after moving in to their new build property, the visiting engineer often failed to recognise and understand a thermal store. Rather than being able to diagnose the problem, they would rip it out entirely and replace with a combi boiler (which were becoming extremely popular).

Below is an example of such a memo (8-pages)

Air to Water Heat Pump Systems are Great

They really are, but you need a good engineer, which is why I set up the Guild to help people find a competent engineer and to help good engineers find customers.

The UK’s plan to decarbonise the nation’s heating systems won’t be able to rely on qualifications. The qualification/accreditation system has not worked for decades and it won’t work now.

If A2W heat pump systems are great, then why so many poor installs? The A2W heat pumps Achilles’ heel is the fact they have a vast possible range of efficiency: basically they are easy to install badly.

If a boiler is installed poorly, (millions are still being installed with on/off control) no one tends to notice or bother. If you have an A2W heat pump installation performing badly you will generally know about it from your bills.

For most A2W heat pump systems to perform well, and not have breakdown issues, the UK is relying on a very competent workforce and a whole plethora of manufacturers controlling their quality issues. That is a big ask.

If we look at the table below, the recent trials were managed programmes. Even though they were managed, the entities involved in the management were unable to control the quality of the labour. If a country can not control the quality of the labour force in such small scale trials and installs then we have little hope of controlling the massive heterogeneous labour force out there in the real world.

Some Conclusions & Thinking Points

• Use a good engineer for an A2W heat pump install. They work great if installed and commissioned well. You can find a Guild engineer here

• A2A heat pump systems have less failure points when it comes to design, installation and maintenance (I’ll be covering this in the next article)

• With A2A you generally rely on one manufacturer’s (mfs) training. With A2W not only is the UK reliant on the HP mfs training but a vast range of other mfs training e.g. there is training from diverter valve mfs, from circulation pump mfs, from magnetic filters and air separator mfs, from expansion valve mfs, from controls mfs, from chemical inhibitor mfs etc…

• For such a basic human need heating systems in the UK are far too varied and complex e.g. Quiet Mark reported there are now over 820 separate models of A2W heat pumps here.

• Manufactures are constantly bringing out new models of heat pump. Arguably, it adds to complexity. There is also a concern the supply chain for previous model’s internal components is becoming to fragile.

• Certificates, qualifications and accreditation unfortunately do not equal competency.

The Guild of Master Heat Engineers is supported by our Patrons.

Learn more about our Patrons here.

Nathan

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