Houghton Retrofit Process & Questions

[Geronimo John]

On 7/1/2023 at 2:14 PM, SeaDawg said:

I think a few folks just used ez rv rain gutter to channel the water away.

Install was a breeze.  I ended up with the EZ RV gutter approach as well.  

Will be doing the Thermistor relocation and fan control relay hacks this July.  

Will keep you posted.

GJ

[jd1923]

Hey @Geronimo John, I've been studying this thread, on and off over the last year and still need to read and learn more. An extremely quiet Low BTU model makes sense to me, and the Oliver does not require 13.5 BTU at all, given the interior cubic feet and insulated shell. I also need to role this into a lifepo4 upgrade. It will be a one or 2-year plan for me. It only makes sense to do these mods in unison.

I will NOT but another Dometic product for any purpose. I have also read, too many times, how those who bring their Oliver for Truma and custom fiberglass work are "very happy" with their purchase. We cannot afford the time, distance and cost of such, so that's not happenin' for us. Loved how our friend @MAX Burner wrote about your side-by-side comparison last summer.

I abhor motor noises, unless it's my Cummins pulling an incline, or a sports car tuned for performance at 7000+ RPM. We want QUIET and LOW fan speed and I believe the solution just might be a Houghton AC!

Ran across these components in research today and somehow, I want to make this work! I read here about some member(s) are wiring 12V batteries in series which would of course produce 24V but then I'm wondering how, do you step 24V down to 12VDV for all the standard RV lighting and other accessories. How about 48V to 12V? Is that possible? Do we have any true battery/solar experts here? 

I'm going to spend weeks/months researching this, but is there a way to pair these components in an Oliver? I would truly love the read the opinion of all members who know the physics behind this! (maybe this should be a new thread?) Thank you GJ and OTT Forum members -

48V Air Conditioner for RV - 9.5K Low Profile AC Unit with Heat Pump and Remote Control Non-Ducted - RecPro

48V 100Ah LiFePO4 Battery - Heated & Bluetooth (epochbatteries.com)

No inverter required if these two components can somehow be combined in an Oliver. I'm generally more of a "here and now" sort, yet technology will amaze!

[CRM]

7 hours ago, jd1923 said:

Hey @Geronimo John, I've been studying this thread, on and off over the last year and still need to read and learn more. An extremely quiet Low BTU model makes sense to me, and the Oliver does not require 13.5 BTU at all, given the interior cubic feet and insulated shell.

 

I'm with you on an Oliver not needing a 13.5k unit. We have a Coleman 9.2k which controls the heat and humidity here in Florida perfectly. My only issue is the age of our unit and that it lacks a heat pump and I want to change it out before we hit the road for an extended period of time in a couple of years. Looking at the 110 version of the 48v you linked to and it seems to check all the boxes. I know the Houghton's "issue" with the fan always running but hoping with a lower BTU unit that the compressor will run longer resulting in a lower amount of humidity in the cabin as well as on the evaporator coil so it won't be the issue it is on higher BTU units.

Also, I think if you run the math that you won't be happy with the run time of that 48v unit on that 100ah battery. Maybe 1.5-2 hours?

[Geronimo John]

JD:  Four considerations to ponder:  .  

+++++++++++++++++++++++++++++++++++++++++++++++++++++

48V vs. 12V EFFICENCY:  Here is the Recpro graphic:

2400 watts vs. 2400 watts.  Yep physics and math do not lie. 

Conclusion:  Per their graphic, there is no efficiency improvement other than the efficiency of the cost of copper wiring.

+++++++++++++++++++++++++++++++++++++++++++++++++++++

COST:  Here are the RecPro graphics for the 48V and 12V models:

Conclusion:  Why pay $950 more for a 48V for the same capacity?

+++++++++++++++++++++++++++++++++++++++++++++++++++++

AVAILABILITY:  

I would bet an Art beer that the availability of 12 volt parts is significantly greater than the 48 volt ones.  

+++++++++++++++++++++++++++++++++++++++++++++++++++++

OTT ELECTRICAL SYSTEM COMPLEXITY:

• Setting up your batteries for 48V is easy.  But also needing 12V for lights and other components will require at least a transformer. 
• Changing all 12V electrical to 48V is next to impossible due to the scarcity of options for 48V components.
• Having a 12V system, and a 120V system and a 48V system will for sure complicate life as well.

Conclusion:  Lots of extra cost and headaches!

+++++++++++++++++++++++++++++++++++++++++++++++++++++

RECOMMENDATION:  If you are buying a new Class A, sure 48V is a good thing to look into.  But for anything smaller I just don't see the benefits out weighing the negatives.

GJ

 

Edited May 31 by Geronimo John

[jd1923]

Agreed @Geronimo John, as always you provide a solid engineering basis. It was a late night find, looked cool at the time! First thing I thought this morning is at a campsite, the 48V DC version is not a simple plug into shore power.

Which model did you install? Do you believe the 9.5k unit is adequate cooling for the Oliver? I'm thinking so, we do not plan on extended summer camping in the east. At 1590W it appears it can run off our 2KW inverter, agree?

I realize on my current 450AH lead-acid batteries it would not run for long, but later adding 600AH Epoch LI should do the trick. RV Air Conditioner Low Profile 9.5k Quiet AC Unit with Optional Heat Pump and Remote Control, Non-Ducted - RecPro

Thanks for your feedback. When I replace our AC, thinking before leave for the October Texas Rally, I should have many more questions. I believe I read you are integrating the thermostat this summer and I would want to do that immediately. I'll be reading here for your updates.

Likely will channel the condensate drip to the rear streetside in some way. It's not like our Oliver is what old-car guys call a "trailer queen!" 🤣 (pun intended) Thank you.

[SeaDawg]

That Houghton a/c  48v  is 48v dc only, not 110 ac.  Can't be run on 120. I guess the point is to run directly from battery, no loss from inverter.  Clearly labeled "not for marine use", so that's not the reason.

24 and 48v systems are common on boats, stepping down to 12v, or separate 12v bank for lights, etc. 24 and 48v systems are often designed for big winches, windlass, bow thrusters, and electric drives. Eliminates long runs of heavy Guage wire, power loss, heat gain, etc.

I was really surprised to see that on the recpro site.  Can't imagine it's a big market.

Edited May 31 by SeaDawg

[Ronbrink]

I haven’t read any mention as to whether or not the Houghton needs a soft start or similar unit, especially if running on a battery bank/inverter.

Edited June 1 by Ronbrink

[SeaDawg]

Houghton keeps adding options. I see that a pre-installed soft start is now available for bigger models, and a Heat pump for the little houghton that we have. Sadly, the heat pump is not available for retrofit to our older unit. I checked.

 

[Nan]

Grandson installed the Houghton 13.5 AC about a week ago. It is so quiet, but the fan ran all of the time. And the humidity was up to 95%..I could not take that, so Grandson installed a switch that shuts down the fan. And the humidity is MUCH better. It also came with a Thermistor Probe, but he has not had time to install that.  The only thing that it is doing that is a little funky is  the hand held controller is set on 72 and the temp. in the Oliver is about 82..

 

[SeaDawg]

@Nan, your grandson is a peach. 

[Nan]

He sure is!!  And he sold the old air conditioner for $550 on Marketplace in less than 24 hours! That really offset the price of the Houghton!!

 

[jd1923]

16 hours ago, Ronbrink said:

I haven’t read any mention as to whether or not the Houghton needs a soft start or similar unit, especially if running on a battery bank/inverter.

Running off of a 2KW inverter (or compressor as mentioned) is likely a no-go. They list this at the bottom of their spec insert on the RecPro page:

This AC unit requires a minimum 2500-watt generator with a dedicated 30-amp service. Using a lower-rated generator may cause difficulty when starting the AC unit or may require a soft starter.*

*It is recommended to use a 3000-watt generator with a dedicated 30-amp service.*

[jd1923]

18 hours ago, Nan said:

Grandson installed the Houghton 13.5 AC about a week ago. It is so quiet, but the fan ran all of the time. And the humidity was up to 95%..I could not take that, so Grandson installed a switch that shuts down the fan...

Any chance you (or others) can explain what kind of switch? How/where installed?

It must be integrated to the thermostat, so when it reaches temp, after the compressor shuts down, the fan stops 1-2 minutes after.

The ONLY good thing about the Dometic is that in AUTO mode is behaves this way. I run the Dometic in our Oliver during late July-August when we got hot up here. Set at 84 to keep the interior from getting too hot when parked. It runs most of the afternoon while in the hot sun and it turns off all night long (we drop 30 degrees every 24 hours up in the dry mountains).

[Geronimo John]

On 5/31/2024 at 8:06 AM, jd1923 said:

Which model did you install? Do you believe the 9.5k unit is adequate cooling for the Oliver? I'm thinking so, we do not plan on extended summer camping in the east. At 1590W it appears it can run off our 2KW inverter, agree?

I installed the 13.5 KBTU heat pump.  It already has a soft start program that ramps up the start.  Some folks have the Soft Start installed in addition.  No need for it with my Honda 2200.  The 2.5 KW and Soft start I believe was a knee jerk reaction to the Yamaha 2000.  That unit has an undersized motor and will not pull up most AC's.  

I ran my old Dometic, which pulled a lot more power than the Houghton, on my Lead Acid batteries with a 2,000 watt inverter.  Worked fine.  BUT... did not last more than an hour max.  I strongly suggest adding a  separate A/B switch for the AC unit.  Here is my DIY guide for doing so.

DIY - Add Air Conditioner Power ATS.docx

I also recommend installing a 3,000 watt inverter when your factory 2K one dies.  

DIY - Renogy 3000 Watt Inverter Upgrade Thoughts.docx

 

On 6/1/2024 at 2:08 AM, Ronbrink said:

I haven’t read any mention as to whether or not the Houghton needs a soft start or similar unit, especially if running on a battery bank/inverter.

The max current draw of the smaller Houghton is well below the Honda (as well as the 13.5K unit) generator's surge AND running amps.  Several of us are running the larger units on 2K Hondas.  I suspect the smaller would as well.

Now for the 800 pound gorilla question:  9,500 or 13.5K Houghton's:       

• With the RELAY & THERMISTOR hacks, the larger unit works exceptionally well as the recycle time and humidity issues are fully resolved.  So no worries once hacked.  
• Our 2018 OE2 has a single layer of Reflectix insulation. 
• We camp out West in very hot almost zero shade areas most of the time.
• We are not in the trailer much during the day, so we may cycle on the unit occasionally, but boondocking it is never left on all day or night. (No shore power and only a Renogy folding suitcase solar).
• For our use, when I want A/C, I don't want to wait 50 minutes for it to cool down Ollie. 

Combined the above usage characteristics lead to our getting the 13.5K unit.

I have heard, but still do not fully believe, that at some point after our unit OTT doubled the Reflectix insulation.  (VERIFICATION REQUESTED).  IF VERIFIED, and if your camping is not generally in extreme conditions, and you have solar or shore power, then I would go with the 9.5K unit.  

Hope the above is beneficial.

GJ

DIY - Add Air Conditioner Power ATS.docx

[Geronimo John]

On 6/2/2024 at 6:33 AM, jd1923 said:

Grandson installed the Houghton 13.5 AC about a week ago. It is so quiet, but the fan ran all of the time. And the humidity was up to 95%..I could not take that, so Grandson installed a switch that shuts down the fan...

On 6/2/2024 at 6:33 AM, jd1923 said:

Any chance you (or others) can explain what kind of switch? How/where installed?

I was first to suggest on our forum to use a relay to solve the humidity issue by controlling power to the fan by piggybacking on the power to the compressor.  Several months later the Air Stream team working the same issue executed with the idea.  GSM Bear posted the below DIY guide to do so in an Air Stream.  Here it is:

GSM BEAR V2 RecPro Houghton Interior Fan Mod v2.pdf

I will be executing it in July. 

I also will be doing the Thermistor Relo hack as well.  My DIY for an OE2 is in draft state.  But running the thermistor wire between the hulls is a theory and I have three options.  The best one was documented to me by.  AndrewK.  He provided some specific guidance on how he and now others have run rooftop solar wires between the hulls from the buried solar port on the roof in front of the MAX Fan.   But this has not been done from the A/C area,  As such, I'll hold onto my DIY guide until I have done so later this summer.  

GJ

Edited June 13 by Geronimo John

[jd1923]

@Geronimo John so I’m thinking to change my mind to the 13,5K model. Went on RecPro to see it’s not only more expensive but + $350 for the easy start option. Yikes! Is it the 9.5K unit doesn’t need it? Also the 9.5K showed heat pump option, not sure if I care about that. The 13.5K model did not show the option, so it must be standard. Came to $1700 total, free ship plus tax and through 6/3 store wide 10% OFF. I’ll likely wait for the next sale, since I’m not sure and not traveling soon. Thanks

[jd1923]

Been reading older Houghton threads here. It seems several have stated the soft start is not required, even off inverter to small generator, please comment. That would be a good save at $350!

Also, what is the Oliver roof thickness at the AC opening? I have not read this being discussed. An option for the "thick roof kit" for >2 3/4". Likely it's less since this has not been mentioned. Thanks

[Geronimo John]

On 6/1/2024 at 11:40 AM, Nan said:

It also came with a Thermistor Probe

Some testing by an OTT owner indicated the best place to run the thermistor sensing end is where the Dometic T-stat is/was located.  Once in that area just need to poke the end of the thermistor out the street side.  Why here? it is out of the direct air flow from the unit and as such gives a truer temperature of the cabin.  This install was done by others on SOB's, but not yet to this location that I am aware of.  I will be doing mine in July and will post up the method that ended up being successful.  There are three different approaches in my quiver and I have a thermistor that is 10 feet long to get me there.  My goal is to have no wires showing inside Ollie and extending as stated above.  More on this in July....

Try running the unit on low fan speed and drop the  temp down until it maintains a more comfortable temp.

GJ

[Geronimo John]

13 hours ago, jd1923 said:

Been reading older Houghton threads here. It seems several have stated the soft start is not required, even off inverter to small generator, please comment.

Totally agree. I have found that it is not needed if you are using a Honda 2000/2200 inverter generator and a Houghton.  Others may have different results for other generators.

GJ

[Geronimo John]

On 6/2/2024 at 8:38 PM, jd1923 said:

Been reading older Houghton threads here. It seems several have stated the soft start is not required, even off inverter to small generator, please comment. That would be a good save at $350!

Also, what is the Oliver roof thickness at the AC opening? I have not read this being discussed. An option for the "thick roof kit" for >2 3/4". Likely it's less since this has not been mentioned. Thanks

Sorry for the slow response.  Getting ready in Hawaii for my 2024 Summer in Ollie trip.  Running warp speed for next week or so. So bullets on my end for a while...

• Don't have or need soft start with my Honda EU2200.  Will let others with the older Honda EU2000 comment.
• Don't need thick roof kit for OE2 and Houghton.  
• Get a manual thermostat for heat.  Use old furnace wires and double up on existing Dometic wire to control heat post Houghton install.
• Requires two mods:  Thermistor Mod and Fan Relay Mod.  doing mine in July.

GJ

GJ

[Geronimo John]

Update:  July 13, 2024

I completed the Houghton 3400 “Humidity Mod” as presented in the attached "Wiring Modification for Interior Fan" document. This excellent write-up was provided by GSM Bear, Version 2 and posted 7/30/2023.  His document needs to be fully understood before starting this Mod.  It took me about 2 hours working off a ladder on the curb side to carefully complete the mod. 

Suggestions: 

•   The suggested wire measurements are adequate and allow for re-termination if necessary.  No need to add any extra length.
•   I recommend that you prefabricate the new brown, black, and white wires.  Much easier to do so on your bench vs. on the roof. 
•   Then physically plug them into the relay.  One less thing to worry about when on the ladder.
•   You will need all the “Parts and Tools Needed” as listed by GSMBear.

Additional Tools and Supplied I Found Useful: 

•   Ladder
•   Head lamp
•   Wire cutter
•   Magnet on a stick
•   Large Phillips bit
•   Silicone to reseal the electrical box
•   Needle nosed & regular pliers
•   Camera (I took pictures to allow me to “blow up” to get a closer look into the electrical box connections.)

Mod Results:

•   The Houghton ran as expected as the fan shut down with the compressor when it cycled down to low speed (Fan set to auto).
•   Houghton also worked as expected with the fan set to low speed. This is the ultra good dehumidifying and quietest setting.  
•   Significantly lowered the humidity levels in the cabin.
•   I had to set the remote temperature to a MUCH lower setting to get the cabin to a cool level. 
• The unit Cycle time was significantly extended with the mod.  As in extended way too infrequently.

I believe that at the end of a compressor run, the fan shuts down with the overhead super cold coils,  The coils then chill the air in the unit and being heavier it sinks down past the thermistor.  As a result, the process keeps the thermistor “Chilled”.  This delays the restart longer than desired.  Moving the thermister to a location outside of the unit is needed   Hence, the Thermistor Mod is required, as GSMBear states in his document.

More to follow with completion of the Thermistor Mod in the next day or two.

GJ

GSM BEAR V2 RecPro Houghton Interior Fan Mod v2.pdf

Edited 23 hours ago by Geronimo John
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