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Block heaters

Discussion in 'Gen 2 Prius Accessories & Modifications' started by sje333, Dec 19, 2008.

  1. sje333

    sje333 New Member

    Joined:
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    Vehicle:
    2007 Prius
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    Has anyone ever tried to rig up a block heater to heat the engine via a heat exchanger? I like the idea of pre-heating my engine with solar energy. A normal block heater connected to a PV array would work, but what about piping 140-degree-F water under the car from a solar water heater (with a large insulated storage tank)?

    Would the temperature be hot enough to make it worthwhile?

    Is there another thread that discusses fuel economy gains from using a block heater during mild weather (which probably only makes sense if you have a source of clean electricity)? I'll only have a few mornings per year that the car is colder than 50F on start-up. I know it wouldn't make financial sense for me, but it could be a fun demonstration project.
     
    #1 sje333, Dec 19, 2008
  2. JimboK

    JimboK One owner, low mileage

    Joined:
    May 1, 2006
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    Chesterfield, VA
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    2005 Prius
    I can't answer your question about the heat exchanger (though my gut tells me it would be inefficient), but I will address this one. I use the EBH year-round when I can plug in. Regardless of the ambient temp, it gets the car warmed up and operating more efficiently sooner. The warmer it's at on startup, the sooner it gets there. I've seen the car reach full operating temps (157F+) within just a minute or two after a "cold" startup in the summer. It is only above that temperature that the ICE can shut down when not needed for propulsion or to charge the hybrid battery.

    Whether it makes financial sense depends on your cost of electricity. It does for me and, I suspect, for most EBH users. Here is a thread that includes discussion on the economics of it. You'll have to dig pretty deep into the thread to get there.
     
    #2 JimboK, Dec 19, 2008
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