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Air Flow in the Current Enginer Kit

Discussion in 'Prius PHEV Plug-In Modifications' started by SFGiant-and-Plugin-Fan, Mar 15, 2011.

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  1. SFGiant-and-Plugin-Fan

    SFGiant-and-Plugin-Fan New Member

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    I read a forum post from "Smiling Jack" that the five fans on his system were all designed to blow air out of the kit and that he received permission from Jack to change one of the fans so that it blows air into the kit. That sounds like a good idea to me so I checked my kit. My kit is a recent one (bought Jan 31) and it has 6 fans. I am not sure of the air flow direction, but the two fans above of the converter seem to be blowing air out. However, the fan on the outside part of the converter (the one attached to the vent hose) seems to be sucking air in through the converter. If true, I wonder if this is a design change by Jack, inspired by Jack, to run the coolish air from the cabin through the converter and out the box via the other fans. Can others with a recent kit confirm this? If not (i.e., if the converter fan actually blows air out like all the other fans), would it make sense to reverse it?

  2. caffeinekid

    caffeinekid Duct Tape Extraordinaire

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    The air intake is on the charger side of the system. The exhaust is on the converter side.

    A couple of us who live in hotter environments are trying to determine a way of getting more cooling through the system. I am personally interested in cooling the traction battery more efficiently as well. As it stands, it doesn't take much time for it to exceed 114 degrees F, at which point (I believe) the system discourages EV mode.
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  3. SFGiant-and-Plugin-Fan

    SFGiant-and-Plugin-Fan New Member

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    Have you seen this link?

    http://www.eaa-phev.org/wiki/Prius_OEM_fan_control

    Apparently it works very well (per some on the Enginer forum; see http://www.enginer.us/forum/index.php?topic=817.0) and all the parts can be bought at your local radio shack.
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  4. mrbigh

    mrbigh Prius Absolutum Dominium

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  5. seilerts

    seilerts Battery Curmudgeon

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    The fan will also run when commanded by a CAN message, either via bidirectional scantool (Techstream, AutoEnginuity) or a board along the lines of what kietyyyy developed for Plug-in Supply. I'm hoping that we'll be able to figure this one out with pEEf's ScanGauge replacement.
  6. caffeinekid

    caffeinekid Duct Tape Extraordinaire

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    Since you purchased a system, you can email Jack and request "User" status to access the forum.
  7. SFGiant-and-Plugin-Fan

    SFGiant-and-Plugin-Fan New Member

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    An additional note: Update - My system would not charge last night (green light came on immediately even though pack depleted). After "resting" over night, the system was able to charge today. I'm thinking that the problem was that I had some pipe insulation (excess grill block) stored on the right side of the unit blocking the air intake fan. This may have led to overheating of the charger and BMS and shut down. :rolleyes: All seems to be normal now. :D
  8. CraigCSJ

    CraigCSJ Member

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    My Enginer Kit was installed Jan. 24, 2011, and has the two Real Force batteries. My vehicle is a 2004 Prius. I count three fans on the converter (one going out the blue tube on the left) and one fan blowing out the charger to the right. All my fans blow out of the kit.
    I wanted to keep the cargo floor intact, so I put a couple of metal pieces on the underside of the left side of the cargo floor cover to hold the right side of the cover of the storage compartment which now has the blue tube in it instead of the bin. Then on the right side of the flap of the cargo floor cover I cut a hole about 3 1/2 inches wide by 6 inches tall, leaving about 1 inch on top to the hinge, on the right and bottom to the edge of the cover. I then used caulk to attach 1/4 inch hardware cloth over the hole, so stuff doesn't fall through.
    I believe this will allow cooled cabin air to flow into the Enginer Kit and be drawn out by the three converter fans during use of the Kit. The hot air will go out the 6 or 8 air exit holes that are in the Prius (one hole has the blue tube inserted into it). This should work better if I allow outside air into the cabin when the AC is on. During charging, the hole I cut lets the hot air coming out of the charger flow up and into the cabin, and out the windows if they are down during charging.
    I plan to drill a few more holes into the bottom of the Enginer Kit box, just rear of the charger, to allow more air into the kit from the hole I cut. This is because on my install, the spare tire blocks most of the pre-drilled air holes (on the bottom of the kit between the charger and the converter) which air from my hole would use to flow into the kit.
    If anybody reading this sees a problem with what I have done, I would appreciate comment.
    PS. When Jack installed my kit, he wanted to reverse the air flow from one of the two fans on top of the converter, so one would blow air into the kit. I told him to please not do this, as I think my solution is better for me, as it allows me to store cargo where I want and provides an outlet for hot charging air. As I see it, reversing one fan would just recirculate hot air in and out of the kit, getting hotter as the kit is used. If the lid to the left storage bin is removed so it is open to cabin air , then Jack's idea would make sense - but I wouldn't be able to pile stuff in that area. As it is in my Prius, during hot weather I will have to keep my air hole clear of cargo.
  9. SFGiant-and-Plugin-Fan

    SFGiant-and-Plugin-Fan New Member

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    I think we have the same setup Craig. I received my kit in February, 2011. In addition to the 4 fans you mention above, I counted two fans inside the kit, one on the right side of the converter and one on the left side of the charger. I still need to verify the direction of all fans during operation, whether it is right to left as indicated by CaffeineKid in post #2 above, or all blowing out as you suggest. If hot air is only vented out the left side, that would seem to make it easier to engineer things so that hot air is not recirculated into the kit (e.g., as you have done). If hot air is also blown out the right side, I suspect at least some of it would recirculate into the kit through the holes in the bottom.


    If by "right bottom edge" you mean the left bottom edge if I am standing at the back of the car facing the installed cover, then I think I understand what you have done. I'm curious, however, as to why you would cut a hole in the larger, hinged cover and not in the small bin cover? This would probably work better for me as my kit is bolted so far left that the hole you describe would be largely over the top of the kit box. Cutting a hole in the bin cover would seem to work as well and I don't see how it would limit storage space any more than what you've done?


    I have a spare retractable charge cord under the kit instead of the spare tire, so this is not as big of a concern for me, though I suppose a few extra holes would not hurt.


    I agree that we don't want to draw hot air back into the unit. In fact, I think a knowledgable person on this has posted that what we really should do, to avoid getting dust accumulation on the electrical components, is to create a positive pressure inside the unit by blowing all air INTO the kit and letting it escape out vent holes. I'm no expert, but this makes some sense to me. However, I don't think you'd want the vent holes to be on the bottom of the kit in that scenario. Maybe the best solution for the current design is for air to blow in from the right side and out the left as post #2 suggests. I'm going to check my kit tomorrow to see if this is the case for me.
  10. CraigCSJ

    CraigCSJ Member

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    Standing at the back of the car, the hole I cut is on the right. The left edge of the hole is above the right edge of the Enginer box. When the charger is on, I can look through the hole and see the two charger lights. The charger fan pushes air out the right side of the Enginer box, directly under the hole I cut.

    I believe the grill and hole on the right side of the converter and the left side of the charger do not have fans, but exist to allow the cool air in from the air holes drilled in the bottom of the Enginer box between these two components. Normally the charger and the converter are not on at the same time. All fans push air out in my system, as far as I can tell. Craig
  11. SFGiant-and-Plugin-Fan

    SFGiant-and-Plugin-Fan New Member

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    I see what you are doing now. I also see that I must have mistaken the grills on the converter right and charger left as fans. So there are just 4 fans, 3 on the left and 1 on the right. You are probably right that they all blow out (though I have not had a chance to verify). That said, I'm curious as to why you would put your hole for heat to escape on the right side? Wouldn't it be better to have it on the left side because that is where most of the fans are and because the converter, which is on the left side, seems to be the bigger issue with respect to overheating. I suppose it would not hurt to vent both sides, but during driving, most of the heated air is going to be escaping from the left side. Have you heard that charger overheating is an issue?
  12. CraigCSJ

    CraigCSJ Member

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    I put the hole on the right because without it, the heat from the charger would have nowhere to go, and would build up. The first charger I got had its fan reversed, sending hot air into the Enginer box. Halfway through the first charge, it burned up and stopped working.

    On the left side there is a way for the hot air to escape the car, and this is the vent only panel on the left side of the car. This has the blue tube in one air exit. The other seven vents are free to exit more air. This vent system is for letting air out of the car when you slam a door closed, or for letting air out of the car when outside air is brought in the front. But for this to work to cool the Enginer box, I figured there needed to be a clear way for colder cabin air to get into the box, pulled in by the three converter fans. That clear way is the hole I made. As I see it, when driving with the Enginer System working, colder cabin air will be pulled down my hole, into the Enginer box through the charger openings and the vent holes on the bottom of the box, become heated by the converter, and blown into the former bin area and out of the car through the car's vent system. It should work better if I cause the air conditioning system to bring in outside air, rather than just recirculate the air.
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  13. SFGiant-and-Plugin-Fan

    SFGiant-and-Plugin-Fan New Member

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    I see. I checked the other day and it seems that the fan on the charger only runs during charging, not when the kit is working. Only the fans on the left side run when the converter gets hot. My plan moving forward is to look for ways to get more cool air to the underside and right side (as you have done) and to remove more hot air from the left side of the unit during operation. I'm not as concerned about the charger at this point, but will check on the direction of the fan. Thanks for that tip.
  14. CraigCSJ

    CraigCSJ Member

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    Yesterday I removed my converter and took off the cover. I found that there are two fans, one at each end, both directing air towards the left side. That means there are a total of four fans to remove heat from the converter when it heats above a set point. Two in the converter and two above the converter.
  15. stefano5777

    stefano5777 Member

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    I have an 05 prius with a enginer 4kw kit installed this week and we drilled a hole in the cooling duct for the traction battery and ran a pipe from the right side fan of enginer case into traction duct work it significantly lowered temp inside of case.
  16. SFGiant-and-Plugin-Fan

    SFGiant-and-Plugin-Fan New Member

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    That is interesting. I'd like to know how that works for you. Might add it to my cooling mods, which I've described in the "Added Cooling from Cabin" thread in the Enginer User Forum. Basically, I've done 3 things so far:

    1. Ran AC air to the kit from the passenger side AC duct,
    2. Closed the space between driver side fans and the kit to improve air flow (I removed the finger guards on the top two fans and filled in the gap surrounding the 3rd driver side fan between the converter and the kit with foam padding), and
    3. Used some duct work I found at Home Depot to direct the air from the top fans to the same side vent that the hose for the converter fan is directed to.

    Depending on outside temp, I can push cool air or ACed air into the kit from the front vent. I've only had these mods completed for a week or so and the temperatures have not been over 80 deg yet, but I've noticed that the converter fans don't run constently and I've not seen any heat related converter shut downs.
  17. stefano5777

    stefano5777 Member

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    Working on a mod to install a row of very low power fans on top of case in a row bringing air into kit. cutting cargo deck of prius and making a grill out of speaker mesh and support so cargo area is usable but also to bring air in from cabin of prius. As soon as we cut lid of enginer case and build the fan frame I will post pictures should significantly cool kit. also looking into powering the fans via a solar panel do not know how feasible this will be but would be nice to cool fans without drawing power while car is parked.
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