Hybrid passenger compartment heater

[FFHdriver]

Some one mentioned that the Prius uses an electric heater and wondered if the Fusion did too. Looking between the firewall and the engine I see two heater water hoses, which are hot. Please correct me if I'm wrong. I wonder why the Hybrid uses a belt driven water pump instead of an electric driven pump? Probably cost.

[Oman]

The FFH uses heat from the ICE for cabin heat. There are two separate cooling systems, the ICE cooling system has an ICE driven water pump and the motor/electrics cooling system is driven by an electrical water pump.

 

Heat from the ICE is free. The question is if the ICE needs to run more to provide the requested heat and if that is more or less "expensive" that providing that same heat through an electric heater that drains the battery.

 

From what I can see in the service manuals it appears that keeping the emissions system up to temperature in the cold (which all cars have to do) will cause the ICE to activate more than most cabin heat requests.

 

The only part I don't get is the belt driven pump. There must have been a good reason and I doubt it was cost savings. The pulleys, belt, pump, and loss of efficiency would have not been less expensive than an electric water pump.

 

Jon

 

 

Some one mentioned that the Prius uses an electric heater and wondered if the Fusion did too. Looking between the firewall and the engine I see two heater water hoses, which are hot. Please correct me if I'm wrong. I wonder why the Hybrid uses a belt driven water pump instead of an electric driven pump? Probably cost.

[junehhan]

The FFH uses heat from the ICE for cabin heat. There are two separate cooling systems, the ICE cooling system has an ICE driven water pump and the motor/electrics cooling system is driven by an electrical water pump.

 

Heat from the ICE is free. The question is if the ICE needs to run more to provide the requested heat and if that is more or less "expensive" that providing that same heat through an electric heater that drains the battery.

 

From what I can see in the service manuals it appears that keeping the emissions system up to temperature in the cold (which all cars have to do) will cause the ICE to activate more than most cabin heat requests.

 

The only part I don't get is the belt driven pump. There must have been a good reason and I doubt it was cost savings. The pulleys, belt, pump, and loss of efficiency would have not been less expensive than an electric water pump.

 

Jon

 

How does the reliability and durability of a mechanical water pump compare to an electric driven one? I wonder if that was one of the thigns they looked at. Also considering that standard Fusions likely feature a mechanical water pump, it may have also been a cost savings measure so that things are more uniform.

[VonoreTn]

The FFH uses heat from the ICE for cabin heat. There are two separate cooling systems, the ICE cooling system has an ICE driven water pump and the motor/electrics cooling system is driven by an electrical water pump.

 

Heat from the ICE is free. The question is if the ICE needs to run more to provide the requested heat and if that is more or less "expensive" that providing that same heat through an electric heater that drains the battery.

 

From what I can see in the service manuals it appears that keeping the emissions system up to temperature in the cold (which all cars have to do) will cause the ICE to activate more than most cabin heat requests.

 

The only part I don't get is the belt driven pump. There must have been a good reason and I doubt it was cost savings. The pulleys, belt, pump, and loss of efficiency would have not been less expensive than an electric water pump.

 

Jon

 

Jon,

 

I agree with everything you said, and maybe I can add some insight on your apprehension regarding the belt drive on the ICE water pump. I worked on drive belts at Ford for 17 years as a mechanical engineer. Since about 1996, Ford has switched from the classic Neoprene material drive belts to EPDM material drive belts. These belts withstand higher temperatures much better than the older Neoprene belts. Credit goes to Dayco and Gates for coming up with the processes required to manufacture belts with this material. GM switched over at about the same time, Chrysler and Toyota took a few years longer to switch. Where Neoprene belt ribs would crack at about 40 thousand miles, EPDM rarely ever crack unless severely over-heated. Thus these EPDM belts will practically last the life of the car. The flat V-ribbed belts that are used today are very efficient, more efficient than chains or gears. In the range of 90-95% efficient, depending on the load. And much cheaper, since they don't have to be sealed in a liquid tight compartment. The belt on the W/P will be one of my least concerns on my FFH.

 

Electric water pumps are less efficient than engine driven W/P's, since they include the inefficiency of creating electricity with a generator first, a process that at best is around 70% efficient. Electric W/P/s are good at low engine speeds, but have difficulty keeping up with an engine/belt driven W/P at higher engine speeds. For sustained high speed driving, you in general will get more water flow out of a engine/belt driven W/P. Nascar cars and almost all endurance racing vehicles use engine/belt driven W/P's.

[Oman]

Good info. I wasn't worried about the longevity of the belt and pump as they have improved greatly over the years. I was just curious about the choice. Ford moved everything else over to electric because unlike normal vehicles there is a ready supply of high voltage available for motors that are normally pretty inefficient at lower voltages. The power steering and A/C compressor are both electric driven. There is even an electric vacuum pump that kicks in when the ICE is not running for vacuum driven devices. It seemed that having only one thing on a belt would have made them want to drop that belt pretty badly. There would have also been an advantage as an electric pump would have helped provide cabin heat and defrost when the ICE was idle as the block would retain heat for quite a while. The reliability of a belt driven pump must have been considerably better than an electric for them to keep it I would think.

 

From an engineering perspective this vehicle is a unique beast. It is fun to reverse-engineer the design decisions, eh?

 

Jon

 

 

Jon,

 

I agree with everything you said, and maybe I can add some insight on your apprehension regarding the belt drive on the ICE water pump. I worked on drive belts at Ford for 17 years as a mechanical engineer. Since about 1996, Ford has switched from the classic Neoprene material drive belts to EPDM material drive belts. These belts withstand higher temperatures much better than the older Neoprene belts. Credit goes to Dayco and Gates for coming up with the processes required to manufacture belts with this material. GM switched over at about the same time, Chrysler and Toyota took a few years longer to switch. Where Neoprene belt ribs would crack at about 40 thousand miles, EPDM rarely ever crack unless severely over-heated. Thus these EPDM belts will practically last the life of the car. The flat V-ribbed belts that are used today are very efficient, more efficient than chains or gears. In the range of 90-95% efficient, depending on the load. And much cheaper, since they don't have to be sealed in a liquid tight compartment. The belt on the W/P will be one of my least concerns on my FFH.

 

Electric water pumps are less efficient than engine driven W/P's, since they include the inefficiency of creating electricity with a generator first, a process that at best is around 70% efficient. Electric W/P/s are good at low engine speeds, but have difficulty keeping up with an engine/belt driven W/P at higher engine speeds. For sustained high speed driving, you in general will get more water flow out of a engine/belt driven W/P. Nascar cars and almost all endurance racing vehicles use engine/belt driven W/P's.

[VonoreTn]

Good info. I wasn't worried about the longevity of the belt and pump as they have improved greatly over the years. I was just curious about the choice. Ford moved everything else over to electric because unlike normal vehicles there is a ready supply of high voltage available for motors that are normally pretty inefficient at lower voltages. The power steering and A/C compressor are both electric driven. There is even an electric vacuum pump that kicks in when the ICE is not running for vacuum driven devices. It seemed that having only one thing on a belt would have made them want to drop that belt pretty badly. There would have also been an advantage as an electric pump would have helped provide cabin heat and defrost when the ICE was idle as the block would retain heat for quite a while. The reliability of a belt driven pump must have been considerably better than an electric for them to keep it I would think.

 

From an engineering perspective this vehicle is a unique beast. It is fun to reverse-engineer the design decisions, eh?

 

Jon

 

On a V8 engine, the power going into the engine driven water pump is about 4 hp, at 4000 engine rpm, with the thermostat open. On this smaller FFH engine, let's say it will be 2 hp. A 2 HP electric motor is a large motor, and will pull a lot of watts (~1500), at any voltage. Electric fan motors, which are a major generator/battery drain on a conventional car are about half a hp, (370 watts) max. This may have something to do with why they use an engine driven waterpump.

[FFHdriver]

On a V8 engine, the power going into the engine driven water pump is about 4 hp, at 4000 engine rpm, with the thermostat open. On this smaller FFH engine, let's say it will be 2 hp. A 2 HP electric motor is a large motor, and will pull a lot of watts (~1500), at any voltage. Electric fan motors, which are a major generator/battery drain on a conventional car are about half a hp, (370 watts) max. This may have something to do with why they use an engine driven waterpump.

BMW has engines with only a variable speed electric pump. The pump only runs when cooling is needed. I don't know how many Watts they use.

[VonoreTn]

BMW has engines with only a variable speed electric pump. The pump only runs when cooling is needed. I don't know how many Watts they use.

 

What model and year would that be? The only thing I found was this:

 

"Your BMW cooling system's pumping function is handled by its water pump, which keeps the coolant mixture moving.

 

The main BMW water pump is gear- or belt-driven but, in many cars, a secondary electric water pump is used for improved flow and cooling.

 

Critical to the pump's operation is the drive belt that turns it. On most newer cars this is the engine's timing belt. On older cars, the pump and belt are external and run off the main crankshaft pulley with a "V" or flat belt."

 

https://www.autohausaz.com/bmw-auto-parts/b...ng-systems.html

[Zack]

Latest Prius has electric pump, no more belts for anything. Obviously Toyota believes it is right thing to do?

[DaveM]

Latest Prius has electric pump, no more belts for anything. Obviously Toyota believes it is right thing to do?

All they have done with the Prius is just plain try to get every last mpg out of it for bragging rights where as Ford designed theres to be a family auto with all the comfort of a luxury car at a decent price. MPG I believe was not Fords #1 objective. Beside does it really matter? I'm sure there are a number of things on the Fusion that Prius doesn't have like good looks and a rear window you can really see out of. Or a Nav. unit with a far supieror screen that looks more like the difference between regular Tv (prius) and HD TV (Ford)

[FFHdriver]

What model and year would that be? The only thing I found was this:

 

"Your BMW cooling system's pumping function is handled by its water pump, which keeps the coolant mixture moving.

 

The main BMW water pump is gear- or belt-driven but, in many cars, a secondary electric water pump is used for improved flow and cooling.

 

Critical to the pump's operation is the drive belt that turns it. On most newer cars this is the engine's timing belt. On older cars, the pump and belt are external and run off the main crankshaft pulley with a "V" or flat belt."

 

https://www.autohausaz.com/bmw-auto-parts/b...ng-systems.html

Checked with my local BMW dealer. The electric water pump is used on the N52 6 cylnder engine which came out in 2006 and is used in 3 and 5 series cars. It has no belt driven water pump. Technician did not know the Wattage.

[FFHdriver]

What model and year would that be? The only thing I found was this:

 

"Your BMW cooling system's pumping function is handled by its water pump, which keeps the coolant mixture moving.

 

The main BMW water pump is gear- or belt-driven but, in many cars, a secondary electric water pump is used for improved flow and cooling.

 

Critical to the pump's operation is the drive belt that turns it. On most newer cars this is the engine's timing belt. On older cars, the pump and belt are external and run off the main crankshaft pulley with a "V" or flat belt."

 

https://www.autohausaz.com/bmw-auto-parts/b...ng-systems.html

Checked with my local BMW dealer. The electric water pump is used on the N52 6 cylnder engine which came out in 2006 and is used in 3 and 5 series cars. It has no belt driven water pump. Technician did not know the Wattage.

[VonoreTn]

BMW has engines with only a variable speed electric pump. The pump only runs when cooling is needed. I don't know how many Watts they use.

 

It was on the BMW E90. It has some merit, but I don't think it has really caught on, due to the very large cooling needs of cars running at high speeds. It has to be a very large amp motor. If you are using a sustained 100 hp, you are generating 250 hp of heat in BTU/hr, whatever that comes out. Ok, I'll convert:

 

Holy Crap! That's 636,250 BTU/hr, enough heat to warm 6 houses! :wacko: