Possible improvement to the car for cooler areas?

Careful Dan, if you keep it up people will think you are aligned with me and your credibility will be shot.

It wouldn't be hard to hook the EBH and a small cabin heater with heat bank under the driver's seat to the same timer. Imagine the luxury of climbing into a warm cabin and the windows remaining frost free in the morning.

 

Credibility is in the eye of the reader. Muahaha.

I am going to install seat heaters the way I described earlier, but instead of using thermostats to switch them on and off I'll use the carpc's wake-up feature. It will wake up at 4:45 and start the seat heaters on both sides (I drive my wife to public transportation in the mornings). I would be more comfortable if I had a way to teach the carpc to start the car, but this is a much more rigorous endeavor. Not only will the carpc need a dedicated keyfob to switch on and off, it will have to be satisfactorily hacker-proof. I don't know where I'd get the space to teach my carpc how, as all expansion ports of any type are in use. Maybe a USB hub. Blah. Or I could delete one of the driver's side USB ports (where the option plugs are next to the interior light controls).

I still prefer a belt-driven water pump as I've known too many high-quality, expensive electric water pumps to fail in cars like my other one under non-stressful conditions. On the contrary, the mechanically driven water pump in my Mustang has survived extreme conditions, being revved up to 6700+ RPM under 14 lbs boost. I've replaced the alternator three or four times but never a water pump. Why mess with a great thing?

And I still insist, the fewer energy conversions you need, the better. Using engine water to heat the cabin is bad for the engine and bad for efficiency. All you folks remember, this engine requires its heat to stay efficient.

~ dan ~

 

Hi All,

The double pane would not need to be vacuum sealed to be effective. Its also something I did not say, or imply.

The thin layer of air between double panes of glazing reduce convection dramatically. Yet another aerodyamic application. Change the Reynolds number (narrow gap between panes) increases resistance to convection air flow.

Polycarbonate would allow the sun in, and it is not as thermally conductive as glass.

The add-on polycarbonate glazing would not need to go all the way to the edge of the window to be effective. The edge of the window that fits into the gasket could be left at its original thickness, with the polycarbonate coming up close to the gasket.

Fogging would be prevented or reduced by increase of the interior surface temperature exposed to the cabin humidity. Foam tape would be enough of a seal to prevent moist air flow over the interior surface of the exterior glazing. Convection, as mentioned above is reduced, which reduces transport of water vapor over the cool surface.

Another attachment method would be a thin z bracket around the Polycarbonate glazing. The thin z bracket would sandwich along with the stock glazing between the door frame gasket. Outwater Plastics (if they are still in buisness) stocks allot of such plastic extrusions. Allot of it is used in retail store displays.

Not sure where you have lived there Fruzzetti, but its usually 20 below when the water pump, or other cooling system componant goes. I had allot of cooling system adventures including 0 F driving with the car overheating.

The brushless magnetically coupled water pump would take allot of development. A 12 V communtated motor driven electric coolant pump would be failure prone. Is this what you are refering too? What I am talking about does not have brushes or runs at high current of a 12 V motor. These two differences would improve reliability.

 

Has anyone looked at the heat from the main battery pack that is dumped?

From what I read the venting is only required for the 12v, a flap valve controlled by the cabin climate control could be used to divert air from vent to cabin.

It would be low grade heat but that is what is required for cabin heating.

When I get my Prius next week I might rig up something to see what the temperature of the dumped air is.

Jon the Chief

 

About the windows....something I remember from my years in Saskatchewan is storm windows for cars. They were thin, flexible plastic, edged with adhesive, that got stuck on the inside to prevent the formation of ice. The air gap was variable, but pretty small, and they were used on all side windows. Not much of an insulating effect, but you had to wear so many layers of clothes while scraping the rest of the car that it really didn't matter. Also, all the parking lots had electrical outlets to plug your car into, so the block didn't freeze while you were shopping. All the cars were 'plug ins'.

 

Hi Hyo...,

Read above. I apparently reinvented these things in my postings above. I am thinking the hatch window could use one of these especially.

 

I remember reading in Priuschat that the Prius has a heating element in the heater core box for additional heat for the cabin. Perhaps Dan Man or someone else that has a shop manual can confirm this. Also, Canadians use little 12 volt portable heaters that plug into the cigarette lighter to add heat to the cabin.

 

Hi all,

Strangely, looking at some Toyota training documentation for the Prius (check out http://www.autoshop101.com/forms/Hybrid12.pdf, lots of other useful documents at that site) it seems that the Prius already has an electric recirculation pump for the heater core, in addition to the electric coolant transfer pump for the thermos and the mechanical pump for the engine.

I wonder how complex it would be to add a reversing valve to the AC system - turning it into a heat pump. That way you get more heat out for your electricity than if you just ran heating elements. Most of the heavy & expensive components are already there.

-Ben

 

Hi Beeward,

Yep, but we are talking about the engine coolant pump. The socalled "water pump" common to all ICE engine cars.

The only issue with the heat pump idea is that at about 10 F and lower they are somewhat ineffective.

One could make a secondary heat exchanger that the exhaust blows through I guess , and then hook /switch that into the compressor fluid circuit.

 

Hi All,

I think that for really cold places a fueled auxiliary heater is a good solution. Gasoline is dangerous to run such a thing off of, and cold temperature diesel might be better. Heaters are on the order of 80 % efficient. I think there was something about the University of Georgia coming out with a spherical burner that was extremely efficient with super low emissions of CO and HC. That might be a good start.

 

Geez you must be an old fart like me. I remember the old Galaxie 500 with those stuck on.

 

I'm sure not going to bother with something like this:

http://www.proheat.com/tb_truckheaters_images.php

Or this

http://www.espar.com/html/products/technology_coolant.html

I suppose I could just stick one of these things in the hatch and leave it running while parked outside at -30 C or colder:

http://www.trucktrailer.carrier.com/Files/TruckTrailer/Local/US-en/trucktrailer/comfortpro.pdf

Seriously, I'll just keep using my winter front and hope for the best. I also use a winter front on my FJ Cruiser

 

True that my only experience with electric water pumps is in older vehicles used on the strip or track, but in these cases the vehicle is either punished immensely for short durations or punished quite a bit for longer durations. In each test, almost all hobbyists and amateur competitors choose the belt-driven pumps but use elecric fans. We do this because the electric water pumps don't hold up. But the way I look at it is simple: if it's not good enough for a car that gets slightly more beat up than my driver, it's not going in my driver (it should be over-engineered, not merely up-to spec).

No chance. The 1850W blow dryers for hair only push the heat a short distance. I'm thinking 2000 watts per side, minimum.

You want to leave some of this latent heat in the coolant.

Why not just use a small gasoline jet like a clothes dryer would use? Then the kids could reroute it to their tailpipes AHAHHAHA..

~ dan ~

~ dan ~

 

I'm young at heart, and I have a good memory. But yeah, we're probably about the same age.

 

I have to warn you, the memory is the first thing to go.

 

I thought it was the second. I forget what the first one is.

 

Now that I'm out visiting neighbors at the hobby farm, I managed to ask a logger what he does. He has an older Dodge Ram with the Cummins, and years ago he installed a ProHeat like one of the models I mentioned a few posts ago

He claims if he is idling in temps of -30 C or colder, he has to run the ProHeat or the motor will cool off so much he won't get heat in the cab. So what he usually does is just turn off the motor and run the ProHeat.

He still has to start the motor every hour or so to make sure the batteries don't go dead running the ProHeat and the accessories

I mentioned the truck APU and he became excited. Maybe this might work on a Prius, it isn't too huge. Uses about 1 litre of diesel per hour

 

In case anybody hasn't figured this out yet, if you're idling at a light when it's cold outside, quickly turn off the automatic climate control until you're moving again. It stops my ICE every time. Never missed the heat for those few seconds or minutes.

 

That's what VW and Porsche did for years. Worked ok in the bugs, terrible in the vans, and great in the Porsche 911's Problem was, as engine speed increased, so did the heat, and visaversa.

The Prius' problem is that the engine is so efficient the exhaust has very little available heat. (Touch the tail pipe, even on a hot day) The other problem is if the exhaust ever gets a pin hole you can carbon monoxide yourself to death.

Another solution would be a gas fired coolant heater. Webasto makes one that you can program to fire up before you get in the car, so it is warm when you get in. It just goes in the coolant line on the heater circuit. There is no reason that it couldn't be programmed to run to maintain coolant temp even though the engine is running. While it burns fuel, it converts it to heat way more efficiently than running the Ice

Icarus