Surge
Well-known member
In another post I tried to calculate the efficiency loss of the REx vs. the BEV, and with the help of some forum members, it works out to somewhere between 10-17%. About 7% of that is due to the heat pump in the BEV. We know that the heat pump heats the cabin 30% more efficiently than the heater in the REx. (Although we don't know if the 30% applies to specific outdoor temperatures.)
But what if you could install the heat pump in the REx?! It may not be impossible.
We know from BMWi3Owner's post that the heat pump is in the front:
http://bmwi3owner.com/2014/02/heat-pump-in-front/
Also, look at this pictures
With heat pump:
http://realoem.com/bmw/showparts.do?model=1Z22&mospid=56088&btnr=64_1955&hg=64&fg=18&lang=en
Without heat pump:
http://realoem.com/bmw/showparts.do?model=1Z22&mospid=56088&btnr=64_1956&hg=64&fg=18&lang=en
You'll see that the heat pump is just an add on that takes coolant and runs it through the heat pump. Look at hoses 4 and 5.
Also look at the vertical slender object "flow heater elec" in the diagram below:
http://realoem.com/bmw/showparts.do?model=1Z22&mospid=56088&btnr=64_1957&hg=64&fg=18&lang=en
Seems like if you have the heat pump, the coolant runs through it, otherwise hose 4 just runs from the flow heater elec right into the electric water pump (9).
One question is - are all the electric water pumps the same? They would need the extra fitting for the heat pump. They appear to be the same, but maybe someone with a REx can take a picture of it?
But what if you could install the heat pump in the REx?! It may not be impossible.
We know from BMWi3Owner's post that the heat pump is in the front:
http://bmwi3owner.com/2014/02/heat-pump-in-front/
Also, look at this pictures
With heat pump:
http://realoem.com/bmw/showparts.do?model=1Z22&mospid=56088&btnr=64_1955&hg=64&fg=18&lang=en
Without heat pump:
http://realoem.com/bmw/showparts.do?model=1Z22&mospid=56088&btnr=64_1956&hg=64&fg=18&lang=en
You'll see that the heat pump is just an add on that takes coolant and runs it through the heat pump. Look at hoses 4 and 5.
Also look at the vertical slender object "flow heater elec" in the diagram below:
http://realoem.com/bmw/showparts.do?model=1Z22&mospid=56088&btnr=64_1957&hg=64&fg=18&lang=en
Seems like if you have the heat pump, the coolant runs through it, otherwise hose 4 just runs from the flow heater elec right into the electric water pump (9).
One question is - are all the electric water pumps the same? They would need the extra fitting for the heat pump. They appear to be the same, but maybe someone with a REx can take a picture of it?