Got Earplugs?

[SeaDawg]

A few notes on our install of the smaller 9500 unit:

We had another motive for changing out the ac, besides age and noise. The size of  the Dometic 600 interfered with fully adjusting our two sidemounted 200 watt solar panels. We picked up several inches of gap with the new smaller ac unit.

The old  Dometic 600 was a well built, heavy unit, that lasted a long time. The new unit, though well built,  has a lot more plastic, so we'll see if we get the same longevity. I'm also going to have to buy or sew a cover, as the outdoor unit has a huge rooftop grilled opening over the fan  that will offer an open door to mud daubers, dirt, and leaves.

The new unit has the convenience of a remote, but the remote is the only way to  fully operate the small unit. So, I  will be taking very good care of that remote. (Edit to add: limited function is available through a tiny touch screen in the bottom of the plenum. Ac will run at 24 or 22 c, fan on high.)

The indoor distribution box is made of a glossy, lighter weight plastic. It's very slim and sleek, and we gained about an inch of headroom vs our old unit, but it's very light. It also just barely leaves room in the trolley part of the roof to easily remove the washable filters on each side. I'm not sure the larger unit like Katanapilot's would work in the smaller Elite. 

The install went very smoothly because the pieces are well thought out by the manufacturer. If you get the first  indoor piece right, the rest falls into place. 

I wouldn't necessarily recommend our 3 person/two ladders/rope safety install without a lift, unless you have a sure-footed, strong young friend like ours, who volunteered to do the rooftop part of the job. He noted that our roof is very well waxed, and it would have been pretty easy to slip. (And, he's used to working on fiberglass boats.)

You definitely want two, or better, three people, though, to make it an easier job, even with a lift. It's a very precise fit, and one on the roof, one inside, at least saves time and aggravation. 

We used a foam gasket, instead of silicone sealant to install the top plate. This method had served us well for the last ac. If it doesn't work out, removing it and replacing with butyl or silicon will not be that difficult.

 

Edited March 9, 2021 by SeaDawg

[NCeagle]

13 hours ago, SeaDawg said:

We used a foam gasket, instead of silicone sealant to install the top plate. This method had served us well for the last ac.

Hi @SeaDawg, I had originally planned on using 3M 4200 sealant for the top plate since it's "removable" but after thinking things over for a few days I had settled on butyl tape.  I want to avoid silicone or anything "permanent" and difficult to clean off in the future should it be necessary.  I hadn't considered a foam seal until I read your post.  Did you choose foam over butyl originally because of the ease of installation / de-installation or performance?  What brand of seal did you choose?  Thanks in advance!!!

Edited March 9, 2021 by NCeagle
question on what brand of foam seal added

[connor77]

On 3/8/2021 at 8:00 AM, NCeagle said:

 

2.  Have you tested with a 2K generator by chance?  Wondering about needing the EasyStart.

Thanks!

I have this same question so I'm also looking forward to your feedback Katanapilot.  Separately, thanks for taking the plunge and doing this install. 

This is a priority mod for me too when we get our trailer.  I am a light sleeper so the Dometic just won't work.

How cool are you able to get your trailer?  What is the lowest temp setting that you can choose?

Edited March 11, 2021 by connor77
Clarity

[SeaDawg]

Butyl was our other choice, as we use that for boat hatches, trailer windows, vents, etc.. We debated the topic for days, as we had butyl tape on hand, as well. The foam seal is from leisure coach works, via Amazon. It's a nice one piece , dense foam seal, much like the one Oliver used in our original install, 13 years ago.

We used the extra provided strips provided to make leveling "feet " for the rear if the unit. Paul torqued the 4 m8 bolts to 6 lbs, and we'll check it again in 30 days, as recommended. 

Without the foam, the unit would hug the roof, and be about 1/2 shorter. We'll see how it works out. My only concern is all the plastic vs metal in the mounting plates.

[NCeagle]

Another Dometic "power lawnmower" AC bites the dust...

Created a temporary skylight.  What a nice, sturdy, double fiberglass hull with PVC board in between for strength!

And a few pics of the outside of the unit since the first two pioneers (katanapilot and seadog) included different parts...

All in all, it took me ~3.5 hours.  I had two helpers to remove the old unit and put the new one on the roof:  John Deere and my son.  I ended up using Butyl tape on the outside frame because I had some high quality stuff on hand, I'm familiar with it and that's what OTT had used on the Dometic Penguin II I removed.  

Now only time will tell how these things perform and last.  Some of my notes / observations so far to add to what has already been observed:

1.  It's a lot quieter.  I only measured sound at the bed where our heads are with high fan and compressor (about 5' away).  With the Dometic it was ~80 dB (as loud as a power lawnmower) and with the Houghton it's ~60 dB (as loud as a normal conversation).  Definitely will be able to sleep better.

2.  AC and Heat Pump both work on either batteries (Lithium) or the Honda 2200 generator without the EasyStart.  On battery power through the inverter, it ran smooth / fantastic.  However, with the generator there were a few hiccups as the compressor didn't start a few times and the surge protector (I think) made some "strange" clanging sounds.  A 2200 generator alone may be borderline and may need either the EasyStart (if possible) or a pair of generators to be safe.

3.  Fan alone takes 1 Amp on 120V and 8 amps on 12V.  Fan plus AC compressor takes 9 amps on 120V and 90 amps on 12V.  Fan plus heat pump takes 13 amps on 120v and 130 amps on 12V.  I think I'll still be carrying my small Vortex space heater in the winter, but it's nice to have another all electric option when power is available.

4.  The exterior cover is nice, but it's not pure white like the Ollie or the MaxAir fan.  It's a bit of an "off white" I think.

5.  The AC compressor and the heatpump both cycled about every 7 minutes.  I think that's expected since the thermostat is in the unit itself and there's not a lot of air circulation up in the back of the Ollie ceiling.  An additional fan may help.

6.  It's 3.5" shallower than the Dometic on the outside.

Thanks again to katanapilot for researching and finding this alternative and to both seadog and katanapilot for sharing some additional tidbits that helped make my installation painless!

Now I will try to sell my old unit to subsidize this upgrade so we can afford diesel for the next camping trip.  😬

Edited March 9, 2021 by NCeagle

[SeaDawg]

That looks great, John. I'm glad you decided on the butyl. Now, we have three methods to compare. 

[Minnesota Oli]

If I understand correctly you have to pull the control board from the AC and mount it somewhere in the opening so you can still use the furnace through the existing thermostat. If that is right could you describe the process.      

[katanapilot]

31 minutes ago, Minnesota Oli said:

If I understand correctly you have to pull the control board from the AC and mount it somewhere in the opening so you can still use the furnace through the existing thermostat. If that is right could you describe the process.      

I'll offer my two cents as to how I modified the relay board and box.  I removed the AC power lines from the box and reused the quick connect wire connectors from the Ollie's romex wire to the new Houghton AC lines.  I would normally use wire nuts or similar, but I assume OTT has had good results with the quick connectors and if they become problematic - they are easy to change. I opened up the Dometic relay box and removed the board from the box.  I removed the large AC relay (that controlled the compressor on the Dometic A/C) as described in a earlier post. I trimmed a couple of corners on the relay board using the pencil grinder and cut slots in the new box for the DC wire connections to/from the thermostat and furnace. I put the cover on the new box, connected the thermostat and furnace wires and attached high strength velcro to the box.  This smaller box fit nicely up in the void in the plenum (picture provided earlier). I did not save the freeze sensor from the Dometic A/C as the only use for it would be to prevent the "E5" error code that shows up when the Dometic thermostat is powered up.  It doesn't bother me and it doesn't affect the functionality of the thermostat in furnace mode.

Sorry I didn't take a bunch of pictures.

[Minnesota Oli]

2 hours ago, katanapilot said:

I'll offer my two cents as to how I modified the relay board and box.  I removed the AC power lines from the box and reused the quick connect wire connectors from the Ollie's romex wire to the new Houghton AC lines.  I would normally use wire nuts or similar, but I assume OTT has had good results with the quick connectors and if they become problematic - they are easy to change. I opened up the Dometic relay box and removed the board from the box.  I removed the large AC relay (that controlled the compressor on the Dometic A/C) as described in a earlier post. I trimmed a couple of corners on the relay board using the pencil grinder and cut slots in the new box for the DC wire connections to/from the thermostat and furnace. I put the cover on the new box, connected the thermostat and furnace wires and attached high strength velcro to the box.  This smaller box fit nicely up in the void in the plenum (picture provided earlier). I did not save the freeze sensor from the Dometic A/C as the only use for it would be to prevent the "E5" error code that shows up when the Dometic thermostat is powered up.  It doesn't bother me and it doesn't affect the functionality of the thermostat in furnace mode.

Sorry I didn't take a bunch of pictures.

Hey thanks for the reply. I received my Houghton AC last week and now have time to do the install. I appreciate you sharing your research and solution to the noisy Dometic , I think the hard interior of the Oliver makes it worse. I have been following this topic and see that several other owners have made the improvement but have not mentioned anything of this issue of Dometic thermostat requiring Dometic AC for the Dometic furnace to function. Then my Oliver is a 2019 and maybe theirs is set up with different equipment. Well thanks again, I can now move forward with the install now that I have a better understanding of what I dealing with.

Paul       

[NCeagle]

12 hours ago, Minnesota Oli said:

If I understand correctly you have to pull the control board from the AC and mount it somewhere in the opening so you can still use the furnace through the existing thermostat. If that is right could you describe the process.      

And my .01 cents (only half as good as what katanapilot has done)...

I did something similar to what katanapilot did but I was a bit more lazy.  🙂  I removed the 120V connections from inside the relay box as that's mandatory to connect to the new Houghton.  Once those connections are gone it is easy to remove the board as katanapilot did.  This is where I got lazy - rather than remove the compressor relay, trim the board and fit it into a custom box, I just wrapped the board in a non-conductive plastic bubble wrap bag and secured it up in a void in the new AC unit.  Maybe I'll do it right and do the extra work that katanapilot did one day - especially if my board fries in the bag.  😬  "Right" for me would be not having that board in the Houghton at all - I'd just put a new board near the furnace and run a new set of wires.  

I don't have the E5 error like katanapilot.  My freeze sensor is connected directly to my thermostat apparently as the sensor and wire come out of the wire bundle - not the relay.  So I suspect mine was set up slightly differently than katanapilot's but not sure.  I just rolled up the wire and stuffed it back into the roof with the thermostat sensor intact.  No issues yet.

Minnesota Oli, definitely looking forward to a report back on your install after seeing the amazing work you did on the street side heat duct!  

Edited March 10, 2021 by NCeagle

[Minnesota Oli]

2 hours ago, NCeagle said:

And my .01 cents (only half as good as what katanapilot has done)...

I did something similar to what katanapilot did but I was a bit more lazy.  🙂  I removed the 120V connections from inside the relay box as that's mandatory to connect to the new Houghton.  Once those connections are gone it is easy to remove the board as katanapilot did.  This is where I got lazy - rather than remove the compressor relay, trim the board and fit it into a custom box, I just wrapped the board in a non-conductive plastic bubble wrap bag and secured it up in a void in the new AC unit.  Maybe I'll do it right and do the extra work that katanapilot did one day - especially if my board fries in the bag.  😬  "Right" for me would be not having that board in the Houghton at all - I'd just put a new board near the furnace and run a new set of wires.  

I don't have the E5 error like katanapilot.  My freeze sensor is connected directly to my thermostat apparently as the sensor and wire come out of the wire bundle - not the relay.  So I suspect mine was set up slightly differently than katanapilot's but not sure.  I just rolled up the wire and stuffed it back into the roof with the thermostat sensor intact.  No issues yet.

Minnesota Oli, definitely looking forward to a report back on your install after seeing the amazing work you did on the street side heat duct!  

I really value the feedback from both you and Katanapilot, this will be my first experience with RV furnaces , AC's and thermostats. Looking forward to the project and learning the ins and outs of it.

Thanks Again

Paul

[NCeagle]

15 hours ago, SeaDawg said:

That looks great, John. I'm glad you decided on the butyl. Now, we have three methods to compare. 

I am going to water test it later today.  I'm nervous.  Fingers and toes crossed.  😏

[connor77]

Good luck John!  Hope it goes well.  I think lots of us are drafting off of you pioneers so keep us posted on how dry everything stays after your test.   Thanks to all!

[NCeagle]

UPDATE:  Some initial findings / observations on the cooling capability of the Houghton unit.

I have been testing a new ventilation system for my battery compartment and part of that testing involved heavy use of the Houghton AC.  It cools the Ollie great in my opinion, although I ripped out the super loud Dometic before I had a baseline to compare to.  Here's some data that shows the outside temp (near 90F) and the AC cooled inside temp.  The trailer is in my metal garage, so shaded heat...

I had the Houghton set at 68F initially, which keeps the cabin at 72F (cabin is always ~4F warmer than setting).  At 1:00 PM, when things outside were really heating up, I turned the Houghton down to 60F (the minimum cool setting) and it was able to bring the Ollie cabin down to 67F and hold it there.  I think the differential of ~23F cooler in the cabin is admirable.  At 7:00PM I set the Houghton temp to 66F and it held the temp steady at 70F.  The unit does cycle a lot just like the Dometic did - I think that's the way these units work and may also be related to the location of the AC within the Ollie - towards the rear right next to the MaxxAir fan is not ideal according to installation instructions.

On another note, I'm not very happy with the Butyl I used to seal the unit to the roof.  I checked the bolts and they were VERY loose from settling in the heat, so I tightened them up and a bunch of brutal Butyl oozed out.  I'm worried I may have overtightened now and have to water test again.  If this continues, I have the foam gasket @SeaDawgused ready to install.

I played around with the heat as well and while it works I think of it as a backup to the propane furnace.  I tried the dehumidification setting as well but couldn't get a drop of water out of the Oliver with it.  Not sure if / how it works yet.

 

[SeaDawg]

@NCeagle Thanks for all the data, and the chart. That's all good news, except the cycling. I'll be interested to see if that is the same with my smaller unit that cannot be controlled via a thermostat. I don't know a lot about the Dometic thermostat. Does it have variable setpoints for temperature differential, like some modern home thermostats? Adjusting that can sometimes help with short cycling. 

Sorry to hear the butyl oozed.. So far, the foam seal we used seems fine. We didn't do an official water test, but mother nature provided us with several tests via heavy rains and wind, and we found no evidence of leaking inside the trailer.

We haven't checked the bolts yet. We did have to adjust the bolts on the Dometic early on in 2008 and 2009, and a few other times, as the foam compresses over time, so I suspect we'll have to do that with the Houghton, as well.

I haven't had occasion to really use the ac yet, as the weather has been mostly pleasant. When we bring it home next week from the window repair shop, I  will probably run it while I finish setting up the interior for camping season. And, check the bolts.

Our friend who works in the yacht business told me it's pretty common these days for marine ac systems to have a dehumidifier function. It uses the compressor and evaporator at a different rate, to draw out moisture. Uses less energy than the ac, but increases comfort, like our home whole-house dehumidifier. That's a feature I'm really looking forward to trying out. 

Our smaller (9500) ac doesn't have a heat function.

Thanks again for the info. A 23 degree drawdown is plenty for us.  Hope ours achieves the same. The old 13,500 Dometic would freeze us out, and was way oversized for an Elite .

 

[SeaDawg]

I just found this video on the Houghton dehumidifier function. It doesn't really explain the mystery fully, but it's short and interesting. 

https://youtu.be/-ZtMvVrSbsU

[NCeagle]

4 hours ago, SeaDawg said:

I don't know a lot about the Dometic thermostat. Does it have variable setpoints for temperature differential, like some modern home thermostats? Adjusting that can sometimes help with short cycling. 

Hi @SeaDawg, I'm not using the Dometic thermostat for the Houghton - just the remote.  The cycling is probably normal because it does it most (every 6 minutes or so) when it's "maintaining" a temperature.  If I turn it down to cool the trailer, it cycles much less and cools the trailer down quickly.  I trust the thermometers I'm using, but that 67F felt like 55F with the fan on and the AC running.  It was too cold and that was good news!

I'll have to play around with the dehumidifier function a bit more once the humidity gets bad here in NC.  The manual says to set the mode on dehumidify and then set the temperature 1 degree cooler than the room temp.  I just noticed when I tried that my sensors humidity didn't move much but it wasn't super humid to start with.  

I spent the past few hours removing the butyl and putting on the foam seal.  I like it better already as I was able to get the bolts correctly torqued and the foam is 1/2 compressed.  I did use the spare foam to build support pads in the back and level it off too.  Hope this works better.  I don't think the butyl was leaking, but it was getting too messy and I thought it would eventually fail.  Maybe the way I put the butyl on (too much?) or the weight of the unit pressing down on the butyl in the recent heat made room for too much settling.  All I've ever used butyl for before are windows, so this was new to me.  Glad we have options.

 

[SeaDawg]

Ok. I took a brief cruise through one of the dometic thermostat manuals, and it only shows a differential adjustment available in furnace settings, not cooling, anyway. And it's only adjustable by one degree.

If we experience the same short cycling, I'll look for the "room temperarature sensor" in the Houghton and see if moving it a bit makes a difference.  I kind of remember seeing something that looked like a temp probe in the ceiling, before we buttoned up the adu/indoor unit. Now that it's over a month ago, I  wish I'd taken more photos. There's nothing in my manual in the parts explosion for the temp sensor, other than a notation on the wiring diagram, that I  can see.

 

Edited April 8, 2021 by SeaDawg

[SeaDawg]

Which butyl did you use, btw? And curious if you let it sit 24 hours before water test? I'm kind of disappointed that the butyl didn't work for you. We've never used it on something as heavy as an ac, so that could be an issue, for sure. Most of the weight sits on that 14 x 14 opening. But, you said your Dometic was install with butyl, right?

[NCeagle]

9 hours ago, SeaDawg said:

Which butyl did you use, btw? And curious if you let it sit 24 hours before water test? I'm kind of disappointed that the butyl didn't work for you. We've never used it on something as heavy as an ac, so that could be an issue, for sure. Most of the weight sits on that 14 x 14 opening. But, you said your Dometic was install with butyl, right?

I used a roll of butyl that I bought from RecPro when I bought the Houghton.  I did let it sit for a few days before my first water test and all was fine.  I did not bother to water test again after I tightened the bolts yesterday morning and more butyl oozed out (primarily from the areas around the bolts - the corners of the frame).  I doubt it would have leaked but I lost faith and took the butyl out (patience is not a virtue for me 🙂 ).  I'm wondering if I didn't have the urge to keep tightening  the bolts if all would have been fine.  

When I took the Dometic off, I had to scrape butyl away so I thought that's all Oliver had used.  However, once I had the unit down I saw that Oliver had used both a foam seal AND butyl tape.  I thought that was overkill but whatever it takes to make the unit watertight I guess.  I also remember thinking that the bolts securing the Dometic were just barely hand tight.  

[connor77]

John or SeaDawg - could one of you post a link to the preferred foam gasket to use or could you advise if this gasket came with the Houghton?  Thanks.

[NCeagle]

Here you go @connor77...  this is what SeaDawg used and recommended and it is the one I bought and am using now as well:

Leisure Coachworks 14" x 14" Universal RV Roof Air Conditioner Gasket Kit

[SeaDawg]

Since we're all experimenting, it's tough to say recommended.  I do think it's a really good foam seal, though. And, I'll keep you posted if we find issues, later.

[SeaDawg]

9 hours ago, NCeagle said:

However, once I had the unit down I saw that Oliver had used both a foam seal AND butyl tape. 

I think that's not only overkill, but probably problematic, years down the road . Especially with the Houghton. Everything is tightly engineered to seal.

 

 

[Minnesota Oli]

I will chime in because I went with Dicor lap sealant non leveling. I applied it to the under side of the outside mount frame and put it in the opening with four bolts in place. Then I put the inside mount frame in place and hand tightened the nuts with very little force. This assured me the all was lined up properly. I smooth out what squeezed out by dipping my finger in water and forming a bead around the frame.  I let this sit for 24 hours before installing the ac. When I torqued the bolt to 9 ft lbs I looked up on top and saw a couple spots where my formed bead had some small bulges but I'm satisfied that I have a good seal. When time permits I'm planing to write up my version of this AC install.