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

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.

Why are Air Conditioners called Air to Air Heat Pumps

Before we get into the advantages let’s look at terminology and nomenclature.

You’ve heard me explain (on my podcasts) that a heat pump is something moving energy from an evaporator to a condenser. An air source heat pump sources its energy from the air. An air to air (A2A) heat pump moves energy from the outside and delivers it to the air inside as opposed to an air to water (A2W) heat pump which delivers energy from the air to the water running around radiators, underfloor heating or fan coils.

Air conditioning is the name given to A2A heat pumps. If I’m being pedantic, even though the whole sector (including manufacturers) call it AC, it’s actually comfort cooling/heating. True AC equipment looks exactly the same but is much more expensive and has very strict control over humidity. True air conditioning is used in clean rooms, hospital theatres and data centres. It has active control over humidity in the room rather than passive control.

Most of what is outside our homes heating and cooling us (e.g. offices, hair dressers, dentists, petrol forecourts, shops, hotels, bars, restaurants etc is comfort cooling/heating systems not true AC. Having said all this it doesn’t really mater people call it AC, I just think it helps some people understand the variety of technologies out there. And it we are honest, I don’t think many people in Government etc who started the conversations around heat pumps back in 2000s quite understood that the UK already had lots of buildings being heated with them. Lots and lots and lots!

WHAT IS A MINI SPLIT?

A mini split is an outdoor unit connected to just one indoor unit. Both units contain a coil and a fan. In the winter the coil in the indoor unit becomes the condenser and introduces thermal energy (heat) into the room. This means that the outside unit’s coil is now the evaporator.

In summer the indoor unit’s coil becomes the evaporator and removes thermal energy from the room to the outdoor unit who’s coil is now the condenser. Both the indoor unit, the outdoor unit and the hand held device that controls them is made by the same manufacturer which I believe is an advantage and discussed later.

Types of indoor units for AC

In the image above you can see the word “multi-split” so let’s clear that up first. A multi-split has one outdoor unit which has refrigerant pipe connections for ‘multiple’ indoor units. Usually around five. Each indoor unit has its own 2 refrigerant pipes coming from the outside unit.

The above image shows three types of indoor unit which can be used for mini-splits and multi-splits

The Cassette

These are what you see in the ceiling when you walk into a shop, a petrol station and maybe your office. There are literally millions of them in buildings around the UK. They are heating people in the winter and keeping people cool in the summer. If you are honest with yourself you probably did not know they were anything to do with heat pumps. You are not alone. When heat pump technology started to get discussed in the 2000s by people involved with policy there was a remarkable lack of knowledge that heat pumps were already in UK buildings.

Nothing wrong with a cassette in the home if the particular home can accommodate it.

The High Level Wall Mount

You would have seen these in lots of places. My hairdresser has one. Again, there are millions in the UK heating and cooling us. No one I know ever has said you need to insulate a building before you use one.

They are in the glass fronted marquee pavilion at Westminster. This is the place where the lobbyists for hydrogen would gather Ladies, Lords and MPs together to tell them heat pumps don’t work unless in uninsulated buildings.

The Console

The console is a little known beauty. It has some advantages over the wall mount. In winter it will blow warm air out of both its top louvres and bottom louvres. This is. better distribution of heat into the room. In summer it does not blow cold air out the bottom louvres as this would just pool on the floor slightly. It blows it upwards out the top.

What are the advantages of air conditioners - A2A Heat Pumps

• Cheap (I can buy a top range outdoor unit for around £275 & and indoor wall mount for under a £100)

• Live Savers

• Just one manufacturer (more on this in part 2)

• Guaranteed efficiency

• They can last a long time if installed well

• One could be enough

I’m going to talk about the advantages listed above in more detail in a part two. I wanted to wet the appetite and introduce people to the world of A2A.

As you know I’m a big fan of Air to Water heat pump systems. But they do need to be installed well. This is one of the reasons I started the Guild: click this map for a Guild Engineer in your area. The potential of Air and Ground to water het pumps not being installed well is currently very high and issues are being seen everywhere.

The ECO scheme has failed many fuel poor people, while making some installation companies very rich. In my own home town I’ve had people ask me to replace the free heat pump they got back to an oil boiler. I’m no longer on the tools so its very easy for me to answer NO but I feel very sorry for these people.

The Electrification of Heat project IMO was also a failure. Despite being a government funded programme managed by Energy Systems Catapult with a certain amount of control over who was installing the 750 heat pump systems they did not fair well.

The UK is relying on an uncontrolled, heterogeneous self-employed labour force to transition the heating in millions of homes. AC systems also need to be installed properly, but there are less failure points and there are possibly ways a heterogeneous labour force could be controlled better. I’ll discuss this in part 2.

Take care and have a great week

Nathan

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

Learn more about our Patrons here.

Nathan

Subscribe to get more newsletters like this, if you haven’t already.