You don't need to do anything.
The best thing to do is type 'heat pump' in google and it will explain what a heat pump is/does much better than I can.

 

Hi guys

My brand new eGolf - a few days old - has a heat pump.

Does anyone with a heat pump know how you turn the heat pump on?

Or does it come on automatically?

Basically how do you use it?

Apart from it working in winter, but one dealer I know said it can work any time of year e.g. hot summer - sort of working in reverse, converting heat to energy. Is this right??

Cheers
Bryan

No, it doesn’t convert heat to energy. More dealer bollocks.

 

lol.

Well, it does in a way. Within the scientific competence of a salesman I can see why they'd think that was pretty accurate.

All heat is energy, and a heat pump pushes it all around.

True. However, the general "rule of thumb" is that a heat pump tends to use about 20% of the electricity for a given amount of heat generated when compared to (say) a fan heater.

hmmm ... very optimistic. More like a half in an automotive heat pump. Maybe 3x in a dedicated static system.

 

Hi guys

My brand new eGolf - a few days old - has a heat pump.

Does anyone with a heat pump know how you turn the heat pump on?

Or does it come on automatically?

Basically how do you use it?

Apart from it working in winter, but one dealer I know said it can work any time of year e.g. hot summer - sort of working in reverse, converting heat to energy. Is this right??

Cheers
Bryan

Genuine question: does the owners manual not give a simple description complete with diagrams (which settings, buttons, vents etc) on what the user needs to do to operate the heating, ventilation and cooling system.

 

A "heat pump heater" operating in reverse is an air conditioner. It still requires power to operate.

 

True. However, the general "rule of thumb" is that a heat pump tends to use about 20% of the electricity for a given amount of heat generated when compared to (say) a fan heater.

 

It is only a fancy name for a household air-con unit which got fitted into an electric car hoping to save energy. It runs on electric, and that is all. Not too much different than your normal air-con operation-wise.

 

It’s actually the other way around - we call heat pumps lots of different things based on their intended application, eg refrigerators, freezers, air conditioning (actually we mean comfort cooling as true AC would normally also include control over humidity too).

They are not particularly complicated at a base mechanical design level, though the controls that sit on top can be a fair bit more complex when they are reversible (ie can be used to heat or coil).

 

Being as the heat pump uses the outside air as it’s “input” source then it’s performance is negatively affected by how cold it is, but even at very low efficiencies it’s still going to have a COP greater than 1 ie it’s still better than using a resistance heater.

 

Hi guys

My brand new eGolf - a few days old - has a heat pump.

Does anyone with a heat pump know how you turn the heat pump on?

Or does it come on automatically?

Basically how do you use it?

Apart from it working in winter, but one dealer I know said it can work any time of year e.g. hot summer - sort of working in reverse, converting heat to energy. Is this right??

Cheers
Bryan

Strange that you would choose to spec the addition of a heat pump at around £700 pounds, then ask how it works etc after the event don’t you think ?.
They are designed to reduce the drag on the HV battery in cold weather, how affective this really is to offset the cost can only be justified by an owner who has one fitted I guess.
Somebody will be along shortly to point out the advantages of the heat pump I am sure.

 

Heat pumps use less energy to warm a car's interior than a resistive heater, so are becoming popular on various makes and models of electric vehicle.

Whilst a heat pump has several components, we can share some of these with the car's existing air conditioning components, just adding a few pieces to vastly improve heating efficiency.

As is the case with many EV technologies (such as batteries, battery cooling, brakes and other systems), each manufacturer does things slightly differently.

The system used by Nissan, and in a modified form by Renault (to allow for battery cooling), adds just a few components to the standard air conditioning system. Kia and Hyundai's heat pump is a little more complex, but allows waste heat to be taken from motor, charger and inverter cooling thanks to a heat exchanger. It also allows the heat pump to cool and heat the interior at the same time, useful for demisting.

The system on the BMW i3 (an optional extra on models without the Range Extender) is different again, as the heat pump circuit is relatively simple, although the heat generated is used to heat liquid, which then flows through a traditional heater matrix to warm the interior.

The system we are looking at in this article is one fitted to one of the UK's less popular models- the Volkswagen e-Golf, which is one of the most interesting (and complex!) arrangements.

But first we will discuss how a heat pump works.

As you may know, increasing the pressure of a gas increases its temperature. Reducing the pressure will reduce the temperature. If we squash something (and therefore warm it up), then allow it to cool, and then allow it to expand again, we can end up with something colder than we started with- like the cold air out of a tyre when someone has blocked a charging point (JOKE- we do not condone things like this!).

The gas used (generally HFC134a or HFO1234yf) is chosen because it has a suitable boiling point that means we can actually cool it down enough for it to become a liquid, and then turn back into a gas on expansion, meaning it can absorb significantly more heat than just compressing and expanding a gas.

An electric compressor is used both for increasing the pressure and for pumping the refrigerant around the circuit. The electric compressor runs on the high-voltage system, and it is important to use the correct oil when servicing the system as normal air conditioning oil conducts electricity!

The e-Golf's refrigerant circuit is shown below (the green coloured section on the left hand side is the coolant circuit and is not relevant to this article). View attachment 104380
When the system is in cooling mode, the compressor pumps the refrigerant through the interior condenser and it goes on to the condenser on the front of the car. Here, the air coming through the front of the car (assisted by an electric fan if necessary) cools the refrigerant. We then push the refrigerant through an expansion valve, where it then expands again, and the reduced pressure causes a reduced temperature. The ice-cold refrigerant can now collect heat from the evaporator (located inside the car), which cools the car down. The flaps in the car's heater box (not shown) direct air through the cold evaporator but not through the (warm) interior condenser.

The refrigerant then returns to the compressor to start the cycle again.

So what about heating?

The same circuit is shown again below, but instead in heating mode. You will notice some of the valves have changed. View attachment 104382
The compressor (which always spins in the same direction) is still pushing refrigerant into the interior condenser, but now it is going through the evaporator and going into the condenser in the opposite direction. As it travels through the expansion valve, it cools, now allowing the refrigerant to collect heat from outside the car. The flow then returns to the compressor. The hot refrigerant is further heated by the compressor and the heat is "dropped" inside the car via the interior condenser.

Other cars with heat pumps also use a resistive heating element (known as a PTC heater*) as the heat pump only operates effectively within certain temperature limits, and the PTC heater can reduce warmup time. The e-Golf's PTC heater is part of the coolant circuit, and it has no heater matrix.

Below is the now familiar system layout with a few changes- the refrigerant follows largely the same path as before, but is now collecting heat from the coolant circuit via a heat exchanger.

View attachment 104384

Even in this mode, there are different methods of operation. On a cold morning, the PTC heater warms the coolant, and the heat pump refrigerates it again and "moves" the heat into the car. However, if the car has been driving for some time, we can use waste heat from the cooling system. The radiator bypass valve is opened, so instead of heat being removed by the radiator, the valve labelled N632 allows warm coolant to circulate from the high voltage cooling circuit into the heater circuit, where it is then cooled by the heat pump, the waste heat becoming useful heat for the interior.

The system is also able to operate in combined mode, collecting heat from outside air and the coolant circuit simultaneously (see below).

View attachment 104386

The diagrams shown are the same diagrams that we make available to HEVRA member garages to aid fault diagnosis. Fault diagnosis is generally done via diagnostic equipment (there are an array of temperature sensors, each shown as a G-number) and pressure gauges (to measure the difference in refrigerant pressure). The operation of the various valves is generally checked with an oscilloscope in conjunction with a thermal imager- the oscilloscope can check the valve is receiving the correct signal, and the thermal imager confirm whether the valve is in the required position.

*PTC stands for positive temperature coefficient, meaning that as the temperature of the heating element rises, its electrical resistance also rises. This reduces the current flow, making it to a certain extent self-regulating. The heating element can also be switched on and off as required to control temperature. PTC heaters are generally fed with high voltage and operate via a Local Interconnection Network (LIN)- a type of network used in vehicles to reduce the need to run separate wires to each component.

 

Brilliant coverage of how a heat pump works !.
It will take a while to read through it !

 

Is the OP any the wiser as to how to turn the thing on.....

 

You can’t manually turn it on yourself.

 

No, but you can set the controls such that the automatic control system turns it on.

 

Heat pumps use less energy to warm a car's interior than a resistive heater, so are becoming popular on various makes and models of electric vehicle.

Whilst a heat pump has several components, we can share some of these with the car's existing air conditioning components, just adding a few pieces to vastly improve heating efficiency.

As is the case with many EV technologies (such as batteries, battery cooling, brakes and other systems), each manufacturer does things slightly differently.

The system used by Nissan, and in a modified form by Renault (to allow for battery cooling), adds just a few components to the standard air conditioning system. Kia and Hyundai's heat pump is a little more complex, but allows waste heat to be taken from motor, charger and inverter cooling thanks to a heat exchanger. It also allows the heat pump to cool and heat the interior at the same time, useful for demisting.

The system on the BMW i3 (an optional extra on models without the Range Extender) is different again, as the heat pump circuit is relatively simple, although the heat generated is used to heat liquid, which then flows through a traditional heater matrix to warm the interior.

The system we are looking at in this article is one fitted to one of the UK's less popular models- the Volkswagen e-Golf, which is one of the most interesting (and complex!) arrangements.

But first we will discuss how a heat pump works.

As you may know, increasing the pressure of a gas increases its temperature. Reducing the pressure will reduce the temperature. If we squash something (and therefore warm it up), then allow it to cool, and then allow it to expand again, we can end up with something colder than we started with- like the cold air out of a tyre when someone has blocked a charging point (JOKE- we do not condone things like this!).

The gas used (generally HFC134a or HFO1234yf) is chosen because it has a suitable boiling point that means we can actually cool it down enough for it to become a liquid, and then turn back into a gas on expansion, meaning it can absorb significantly more heat than just compressing and expanding a gas.

An electric compressor is used both for increasing the pressure and for pumping the refrigerant around the circuit. The electric compressor runs on the high-voltage system, and it is important to use the correct oil when servicing the system as normal air conditioning oil conducts electricity!

The e-Golf's refrigerant circuit is shown below (the green coloured section on the left hand side is the coolant circuit and is not relevant to this article).

When the system is in cooling mode, the compressor pumps the refrigerant through the interior condenser and it goes on to the condenser on the front of the car. Here, the air coming through the front of the car (assisted by an electric fan if necessary) cools the refrigerant. We then push the refrigerant through an expansion valve, where it then expands again, and the reduced pressure causes a reduced temperature. The ice-cold refrigerant can now collect heat from the evaporator (located inside the car), which cools the car down. The flaps in the car's heater box (not shown) direct air through the cold evaporator but not through the (warm) interior condenser.

The refrigerant then returns to the compressor to start the cycle again.

So what about heating?

The same circuit is shown again below, but instead in heating mode. You will notice some of the valves have changed.

The compressor (which always spins in the same direction) is still pushing refrigerant into the interior condenser, but now it is going through the evaporator and going into the condenser in the opposite direction. As it travels through the expansion valve, it cools, now allowing the refrigerant to collect heat from outside the car. The flow then returns to the compressor. The hot refrigerant is further heated by the compressor and the heat is "dropped" inside the car via the interior condenser.

Other cars with heat pumps also use a resistive heating element (known as a PTC heater*) as the heat pump only operates effectively within certain temperature limits, and the PTC heater can reduce warmup time. The e-Golf's PTC heater is part of the coolant circuit, and it has no heater matrix.

Below is the now familiar system layout with a few changes- the refrigerant follows largely the same path as before, but is now collecting heat from the coolant circuit via a heat exchanger.

Even in this mode, there are different methods of operation. On a cold morning, the PTC heater warms the coolant, and the heat pump refrigerates it again and "moves" the heat into the car. However, if the car has been driving for some time, we can use waste heat from the cooling system. The radiator bypass valve is opened, so instead of heat being removed by the radiator, the valve labelled N632 allows warm coolant to circulate from the high voltage cooling circuit into the heater circuit, where it is then cooled by the heat pump, the waste heat becoming useful heat for the interior.

The system is also able to operate in combined mode, collecting heat from outside air and the coolant circuit simultaneously (see below).

The diagrams shown are the same diagrams that we make available to HEVRA member garages to aid fault diagnosis. Fault diagnosis is generally done via diagnostic equipment (there are an array of temperature sensors, each shown as a G-number) and pressure gauges (to measure the difference in refrigerant pressure). The operation of the various valves is generally checked with an oscilloscope in conjunction with a thermal imager- the oscilloscope can check the valve is receiving the correct signal, and the thermal imager confirm whether the valve is in the required position.

*PTC stands for positive temperature coefficient, meaning that as the temperature of the heating element rises, its electrical resistance also rises. This reduces the current flow, making it to a certain extent self-regulating. The heating element can also be switched on and off as required to control temperature. PTC heaters are generally fed with high voltage and operate via a Local Interconnection Network (LIN)- a type of network used in vehicles to reduce the need to run separate wires to each component.

 

I hope everyone realises that 10 year old BEVS with heat pump systems will be scrapped with pretty minor heating system faults. Way to complicated and essentially not repairable for many predictable failure modes KISS is a pretty tried and test principle, seems to have been thrown out the window. Tesla seem to have a better handle on this.

Good news is that some models like i3 allow you to forgive a little range and opt for no heat pump.

 

Many 10 year old BEVs will be scrapped for relatively minor faults, or at least recycled.

Good news is that the heat pump is an option on the e-Golf as well.

But good to hear that this is yet another area where Tesla are superior...

 

Under two dollars a litre in Canada !.
So yes, comparing it to U.K. prices my comment was correct.
We could only wish for them type of prices over here !.
If fuel over the water was as expensive as ours, the country would grind to a halt in only a few days !.
Approx 80% of the cost here is tax to the government etc !.

 

Teslosis? must be catching a bit from my neighbours.

 

I’m just pleased you can laugh about it!