1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

liquid to liquid heat exchanger for on board warm/hot water

Discussion in '3rd Gen. Tacomas (2016+)' started by soggyBottom, Oct 25, 2020.

  1. Oct 25, 2020 at 9:46 AM
    #1
    soggyBottom

    soggyBottom [OP] Well-Known Member

    Joined:
    Sep 19, 2018
    Member:
    #266818
    Messages:
    775
    I saw another thread from @ProForce about having pressurized onboard water,

    https://www.tacomaworld.com/threads...or-the-2005-current-toyota-tacoma-obw.453005/
    [​IMG]


    I've seen a few storage tanks that are black and should generally heat from being in the sun. My idea is likely more trouble than it's worth but wanted to share it. Maybe someone will expand on the idea and make it more feasible.

    [​IMG]

    Basically use the exchanger, to transfer heat from the coolant system to the clean water storage. The same pump in the first picture could be used with a solenoid diverter valve and perhaps a FET to run it at a lower duty cycle for longer periods of time. Scaling would also be an issue on the fresh water size. I'm not sure how to get around this other than just descale it every now and then. The worst part about this idea is likely running the water lines.

     
  2. Apr 19, 2021 at 8:16 PM
    #2
    mk5

    mk5 Probably wrong about this

    Joined:
    Mar 15, 2018
    Member:
    #247373
    Messages:
    510
    SoCal
    Vehicle:
    '05 access cab 4x4
    Hey I stumbled across this post looking for something else... but wanted to say, I did this exact thing in my truck and it is great. It took a couple of years of intermittent effort. I cannot possibly recommend it as a good use of your time. But having hot water on demand is super nice. You can read about it here, here, and here.
     
    Ncska21, vecdran, deanosaurus and 3 others like this.
  3. Apr 19, 2021 at 8:31 PM
    #3
    OnHartung'sRoad

    OnHartung'sRoad -So glad I didn't take the other...

    Joined:
    Jul 24, 2017
    Member:
    #224878
    Messages:
    6,636
    Somewhere in the Mojave Desert...
    Vehicle:
    2017 Tacoma OR 4x4 (formerly 2002 OR 4x4, 1995 4x4 4Runner, 1985 4x4 Toy PU) ... and RIP’s (rust in pieces) to a Bronco II 4x4 & S10 Blazer 4x4
    Wow, your hot water setup is really nice work, and I’m not trying to poop on it, but I bought one of these and made the job a lot easier. I was kind of proud of it until I saw what you did - man that is a beautiful set up, but I can imagine the amount of work you put into it. Plus for those of us that don’t have the welding equipment, it would be rather expensive to start a project like that.

    Hot water on demand Campworld Low Pressure 1.58GPM/6L LPG Portable Propane Gas Hot Water Heater:

    https://www.amazon.com/dp/B08GFDZJB1/ref=cm_sw_r_cp_api_glt_fabc_9BGEVD645JY2KV6R735M
     
    mk5 and JaCado like this.
  4. Apr 19, 2021 at 8:40 PM
    #4
    DanoTay

    DanoTay Active Member

    Joined:
    May 4, 2020
    Member:
    #326717
    Messages:
    39
    Gender:
    Male
    Victoria, B.C.
    Vehicle:
    2019 Tacoma OR AC MT
  5. Apr 19, 2021 at 8:59 PM
    #5
    JEEPNIK

    JEEPNIK Well-Known Member

    Joined:
    May 5, 2020
    Member:
    #326895
    Messages:
    1,310
    Gender:
    Male
    Vehicle:
    2020 Voodoo Blue TRD Sport
    Old idea. Although the ones I saw years ago used a manual valve for isolation and a bimetallic valve for temp control.
     
    Gunshot-6A likes this.
  6. Apr 19, 2021 at 9:16 PM
    #6
    Key-Rei

    Key-Rei Well-Known Member

    Joined:
    Jun 20, 2017
    Member:
    #221942
    Messages:
    4,391
    First Name:
    Key
    Florida
    Vehicle:
    2010 TRD Off-Road 6Spd 4x4 209BSM
    Locker anytime Fog Lights anytime Full LED light conversion TRD cat back Rear cat delete Exaust Y reroute away from actuator Alloy Clutch master 2000 4Runner "Dog Leg" shift leaver Marlin shift seats and bushing Rear seat delete Rear diff breather extension Chrome grille swap Debadge Rear seat delete Honda blower motor beefy plug and wire mod Anytime 12v and USB with volt gauge in bed Blue Sea fuse box Hella AND 70's Caddy horns Low profile recessed hex drain plug swaps Alluminum battery strap 7pin relocated Backup cam on anytime Various other creature comfort and personal taste mods.
    That's an interesting idea, think I might just go cheap and buy a garden sprayer and wrap it in reflectix or something though. :rofl:
     
    Skydvrr likes this.
  7. Apr 19, 2021 at 9:20 PM
    #7
    mk5

    mk5 Probably wrong about this

    Joined:
    Mar 15, 2018
    Member:
    #247373
    Messages:
    510
    SoCal
    Vehicle:
    '05 access cab 4x4
    Lol nice to see the conversation jump into gear. There's no right or wrong way to go about this, I just wanted to highlight my approach as one of the many ways to do this, and one making use of a heat exchanger to harvest engine heat per OP's OP.

    The downside is that it's a ton of work, probably a few hundred hours counting learning how to weld and running 220V to my garage! The upside is it's a tuly on demand system, no setup required, just pull the sprayer out of the bedside and you have water like your kitchen sink sprayer. If the engine is warm, then you get tempered hot water, perfect for showering and doing dishes. It has 13 gallons capacity with zero lost bed space, but was a huge endeavor to install.

    I wouldn't trade my setup for the world, but if I had to do it again, I'd probably just go with a propane heater!

    This was one of those projects where you do it to prove you can, not because it makes the most sense!

    An old one but a good one... I included such valves as well.
     
    Last edited: Apr 19, 2021
  8. Apr 19, 2021 at 11:19 PM
    #8
    JEEPNIK

    JEEPNIK Well-Known Member

    Joined:
    May 5, 2020
    Member:
    #326895
    Messages:
    1,310
    Gender:
    Male
    Vehicle:
    2020 Voodoo Blue TRD Sport
    If you had already known how to weld I’d have thought you were a steam fitter. We use liquid to liquid exchangers quite a bit for heat recovery and cooling.
     
    Key-Rei likes this.
  9. Apr 19, 2021 at 11:59 PM
    #9
    mk5

    mk5 Probably wrong about this

    Joined:
    Mar 15, 2018
    Member:
    #247373
    Messages:
    510
    SoCal
    Vehicle:
    '05 access cab 4x4
    I have installed gas lines for pyrophoric neurotoxins in R&D settings, but I know damn well not to mess with the steam lines! Some things are best left to the pros.
     
    Last edited: Apr 20, 2021
  10. Apr 20, 2021 at 12:35 PM
    #10
    DanoTay

    DanoTay Active Member

    Joined:
    May 4, 2020
    Member:
    #326717
    Messages:
    39
    Gender:
    Male
    Victoria, B.C.
    Vehicle:
    2019 Tacoma OR AC MT
    I tried a garden sprayer in the past but found that it is Hot Jugz' low flow shower head that allows one to shower with 2 gallons of water. It also has a pressure release valve.
     
  11. Apr 20, 2021 at 5:10 PM
    #11
    JEEPNIK

    JEEPNIK Well-Known Member

    Joined:
    May 5, 2020
    Member:
    #326895
    Messages:
    1,310
    Gender:
    Male
    Vehicle:
    2020 Voodoo Blue TRD Sport
    Never messed with that stuff. But have done high purity stainless stuff and chemical lines.

    The old guy that taught me said to just think first and take your time. It isn’t a race. Funny thing about that type of knowledge. I passed it on to those I taught.
     
    mk5 and Key-Rei like this.
  12. Apr 20, 2021 at 6:28 PM
    #12
    Key-Rei

    Key-Rei Well-Known Member

    Joined:
    Jun 20, 2017
    Member:
    #221942
    Messages:
    4,391
    First Name:
    Key
    Florida
    Vehicle:
    2010 TRD Off-Road 6Spd 4x4 209BSM
    Locker anytime Fog Lights anytime Full LED light conversion TRD cat back Rear cat delete Exaust Y reroute away from actuator Alloy Clutch master 2000 4Runner "Dog Leg" shift leaver Marlin shift seats and bushing Rear seat delete Rear diff breather extension Chrome grille swap Debadge Rear seat delete Honda blower motor beefy plug and wire mod Anytime 12v and USB with volt gauge in bed Blue Sea fuse box Hella AND 70's Caddy horns Low profile recessed hex drain plug swaps Alluminum battery strap 7pin relocated Backup cam on anytime Various other creature comfort and personal taste mods.
    I've messed with steam lines just a little bit, low pressure, low volume, I don't think I want to be anywhere even close to PYROPHORIC NEUROTOXINS!?

    :eek:
     
    mk5 and OnHartung'sRoad like this.
  13. Apr 21, 2021 at 7:19 AM
    #13
    OnHartung'sRoad

    OnHartung'sRoad -So glad I didn't take the other...

    Joined:
    Jul 24, 2017
    Member:
    #224878
    Messages:
    6,636
    Somewhere in the Mojave Desert...
    Vehicle:
    2017 Tacoma OR 4x4 (formerly 2002 OR 4x4, 1995 4x4 4Runner, 1985 4x4 Toy PU) ... and RIP’s (rust in pieces) to a Bronco II 4x4 & S10 Blazer 4x4
    :gossip:What ever you do, don’t let that guy get disgruntled at your workplace!

    Yeah, that welding workmanship is impressive!
     
    mk5, Key-Rei and Gunshot-6A like this.
  14. Apr 21, 2021 at 2:04 PM
    #14
    mk5

    mk5 Probably wrong about this

    Joined:
    Mar 15, 2018
    Member:
    #247373
    Messages:
    510
    SoCal
    Vehicle:
    '05 access cab 4x4
    What I worked on was just quarter inch stainless tubing ... but using an orbital welder on stainless tubing is nothing like learning to mig weld! It's a fully automatic machine, you just cut the tube to length, clean it, and stick both ends in this machine. It does everything else magically. I probably wasted half the material we bought because I'm so bad at eyeballing, er, uh, "measuring" lengths, especially accounting for the bends... but the welds were always perfect!

    Mig welding is much harder to pick up, but a hell of a lot more useful for working on a truck!
     
  15. Apr 21, 2021 at 7:20 PM
    #15
    JEEPNIK

    JEEPNIK Well-Known Member

    Joined:
    May 5, 2020
    Member:
    #326895
    Messages:
    1,310
    Gender:
    Male
    Vehicle:
    2020 Voodoo Blue TRD Sport
    Makes me wonder, how many even know how to gas weld anymore. When I learned there was a logical progression.
    Solder, braze, gas weld then arc. Sometimes after that mig & tig came along.

    Though as long as we’re talking burning metal, my hats off to the guy that invented the plasma cutter.
     
    OnHartung'sRoad likes this.
  16. May 3, 2021 at 5:44 PM
    #16
    ebarrere

    ebarrere Member

    Joined:
    May 29, 2018
    Member:
    #254907
    Messages:
    23
    Vehicle:
    2007 Tacoma, TRD off-road
    3” lift, 32s
    Hey guys — thinking of doing this on my 2nd gen soon! Where does everyone tap in the heat exchanger?

    My brief look under the hood seemed to reveal coolant lines running through the firewall on passenger side, but not sure which is source and which is return. Also appears they’re steel so not sure how to tap in without breaking something :) is the little plastic dealie on there a quick release of some sort..?

    Thanks for any advice!
     
  17. May 3, 2021 at 6:24 PM
    #17
    mk5

    mk5 Probably wrong about this

    Joined:
    Mar 15, 2018
    Member:
    #247373
    Messages:
    510
    SoCal
    Vehicle:
    '05 access cab 4x4
    I think you're looking at the AC lines.

    Check out the description I linked in post 2 above, it shows where I installed and tapped into mine.
     
  18. May 4, 2021 at 8:57 PM
    #18
    ebarrere

    ebarrere Member

    Joined:
    May 29, 2018
    Member:
    #254907
    Messages:
    23
    Vehicle:
    2007 Tacoma, TRD off-road
    3” lift, 32s
    Thanks, but I don’t really see anything about it other than you used 5/8” hose and heat shielding. There is a picture but it’s very unclear to me where these actually tap in to the existing cooling system...

    Am I missing something?
     
  19. May 5, 2021 at 3:57 PM
    #19
    mk5

    mk5 Probably wrong about this

    Joined:
    Mar 15, 2018
    Member:
    #247373
    Messages:
    510
    SoCal
    Vehicle:
    '05 access cab 4x4
    I recommend tapping in to one of the hoses for the heater core, and connecting the heat exchanger in series with it. The heater core is in the dash, with two connections at the firewall behind the engine, slightly to the drivers side. These are the 5/8" hoses, and each connects basically to the rear of the engine. They're somewhat difficult to access, but you can see them coming from the firewall inboard of the brake booster. I don't think it matters which side you tap, so long as you do it correctly. Water will flow through the heater core and the heat exchanger, in one or the other order. You can install a 4-port diverter valve to turn off flow to the heat exchanger, without blocking flow to the heater core. If you used a regular 2-port shutoff valve it would block coolant to the heater core as well.
     
To Top