How does the heat pump work in a Toyota Prius Prime plug-in hybrid?

Discussion in 'Prime Technical Discussion' started by priuscatprimeguy, May 24, 2017.

  1. lech auto air conditionin

    Joined:
    Sep 5, 2011
    330
    208
    192
    Location:
    san francisco
    Vehicle:
    2012 Prius c
    Model:
    Two
    D9D1A616-6BB3-4219-969F-5390E7AFFB98.jpeg 62B9C3D4-11F8-4DEF-9095-DADEB7B50395.jpeg 5BE77C26-0B55-4889-9259-4A1058B64203.jpeg
    Nothing special this is old technology been around for decades automotive air-conditioning is my specialty for the last 30+ years I also have a commercial HVAC business we only install heat pumps and heat recovery systems that make the new Toyota heat pump look like a Mattel toy . The problem is there is no training on the system for mechanics to work on it or even understand it the misdiagnosis for repairs is definitely going to skyrocket at the cost of the customers pocketbook. The biggest percentage of our electric compressor failure is we see coming from customers are DIYs and autobody shops after a collision repair improperly recharging the electric compressor is contaminated refrigerant is another problem in proper oil contaminating the oil hi moisture content from collision repair with the pipes left open today atmosphere for days or weeks well being repaired improper charging a couple ounces to much a couple ounces to low both cause damage to the efficiency in the life of the electric compressor. The damage is not immediate usually except in severe cases it’s more like a ticking time bomb usually seen a compressor failure between nine months to 18 months after a vehicle lease a collision repair center or a do it yourself or tries to go down to the auto parts store with one of those little cans with the little hose in gauge on it and fill it up themselves or with the aid of a friend . As discussed above heat pumps are very efficient compared to using electricity to heat a electric resistive element . Using refrigerant to cool the compressor is ancient technology been around for a long time in the commercial heat pumps produced by Daikon, Mitsubishi, LG, Samsung, FUJITSU, amongst 20+ other manufacturers around the world, I just got to work on my first one from a collision repair was called in to do the recovery of refrigerant so they can take it apart . Condenser was replaced due to damage I was called back in to recharge the system . Looks like in operates very much like the heat pump installed on my house and some of the commercial systems I sell and install. One of the biggest problems were going to see in the future as these cars get into accidents the condenser is being replaced with cheap inexpensive aftermarket condensers that raise the head pressure and lower the efficiency of the system. The reason most aftermarket condensers are cheaper if you actually count the cooling refrigerant tubes for flow of refrigerant you usually find that there are fewer on the aftermarket condenser and you count the fins for cooling per inch you also find there’s fewer fins per inch in combination this lowers the cooling efficiency for the heat rejection of the condenser . And on a heat pump system it will make the heating less efficient in either case gas mileage goes down and the life of the compressor decreases due to the extra load of work it has to perform and On very hot days the extra amp draw for the electric compressor draws down they electric drive battery causing the battery to constantly be in a state of charging and discharging shortening the life of the drive battery . For those of you with experience mechanics more technically inclined you’ll notice sometimes on very hot days when a Prius has a cheap aftermarket condenser the cars engine stays on almost 100% duty cycle to compensate to charge the high voltage battery. Customers bring their cars into shops complaining of poor gas mileage and just because of a condenser unnecessary so called tuneups are performed diagnosis that leaves a mechanic nowhere and the customer losing money. That’s just a short synopsis of the story .
     
    padroo likes this.
  2. schja01

    schja01 One of very few in Chicagoland

    Joined:
    Apr 22, 2005
    1,069
    718
    0
    Location:
    Chicagoland
    Vehicle:
    2018 Prius
    Model:
    Prime Advanced
    An ASHRAE Engineer once told me it's much more efficient to move something from one place to another than building it from scratch at the destination. Exactly what a Heat Pump does vs a Heating Element.
     
  3. Longhood

    Longhood Junior Member

    Joined:
    Dec 18, 2018
    6
    2
    0
    Location:
    S. Jersey
    Vehicle:
    2018 Prius Prime
    Model:
    Plug-in Base
    The heater core is NOT hot in most cars all the time. Coolant is throttled to zero when heat control or thermostat is set to cool.

     
  4. allenbrown

    allenbrown New Member

    Joined:
    Aug 31, 2019
    6
    0
    0
    Location:
    united states
    Vehicle:
    2012 Prius+ MPV
    Model:
    Four
    Thanks for sharing....
     
  5. drash

    drash Senior Member

    Joined:
    Jan 5, 2005
    1,527
    615
    0
    Location:
    Upstate NY
    Vehicle:
    2017 Prius Prime
    Model:
    Prime Advanced
    The A/C and heat all work off of the heat pump, so it’ll work in EV or any mode. The only difference is the Heat Pump doesn’t work at less than 14F, so the engine would kick on and run in Hybrid mode to meet whatever temperature is set. If you force the Prime to use the Front Defroster by pressing that button, then it’ll run the engine until the Front Defroster button gets turned off just like a regular Prius.


    Unsupervised!
     
Loading...