Atwood 15K A/c unit

Topic: Atwood 15K A/c unit (Read 3116 times) previous topic - next topic

Re: Atwood 15K A/c unit

Reply #25 – August 16, 2019, 10:28:48 pm

Yes, I certainly don't want to burn anything up. It would not be something I would try for extended periods - more just as a "science experiment" to play around with. If it doesn't work out - no big deal. Always got the generator to fall back on.

Plus, might give me a good excuse to upgrade my old alternator, which is lookin' kinda crusty...

Re: Atwood 15K A/c unit

Reply #26 – August 16, 2019, 10:35:47 pm

Started chasing wires for the removal of the old AC on my 02 U320... Anyone know what wires are for the aqua hot and will any thermostat work for it (as a stand alone)? I found a green (ground) and white one I think... Back of the thermostat is a phone plug... so figuring it is controlled off the dometic board.

Re: Atwood 15K A/c unit

Reply #27 – August 16, 2019, 10:41:28 pm

The bathroom zone uses a standard thermostat on mine for the Aqua Hot. Would think all zones could be controlled by one.

Re: Atwood 15K A/c unit

Reply #28 – August 16, 2019, 10:42:53 pm

Quote from: craneman – August 16, 2019, 10:41:28 pm

The bathroom zone uses a standard thermostat on mine for the Aqua Hot. Would think all zones could be controlled by one.

Didnt think of that ... would like something more current than 60's technology

Re: Atwood 15K A/c unit

Reply #29 – August 16, 2019, 10:55:37 pm

Pretty sure I read... someones swap... cant remember if it was on here or Irv2 or something.... integration is the problem.. need to figure out the aguahot thermostat controls and how the front and back will connect with adding the rear air thermostat in the bedroom.

Re: Atwood 15K A/c unit

Reply #30 – August 17, 2019, 01:03:02 am

I can't speak to the easy start, but I can speak to Sure Start performance. Look up the LRA (locked rotor amps) for the AC unit. With a Sure Start take that LRA value x .4 to get resulting LRA after installing Sure Start ( I suspect Easy Start is similar). We guarantee a 60% reduction in LRA with the Sure Start (usually closer to 65% reduction in the real world). So 60% lowering of LRA leaves 40% of the original LRA. Hence the equation of original LRA x .4 = New LRA after installing a soft starter.

The LRA is what will trip your inverter offline, after the unit is running the inverter will (very likely) easily handle the RLA (run load amps), but that is worth checking as well to be sure.

To calculate if your inverter will likely start the AC with EasyStart or SureStart, measure your "back-round" load (amps) when not running the AC on the inverter. Add the LRA amps to the back-round amps to get total (surge) amps. Take that amp value x 120 (your voltage) to get (surge) watts. See how close the "surge watts" are to your inverter surge watt capability and it will let you know if the inverter has a chance of starting the roof AC. IF your batteries are not at 100% that will effect the inverter surge amp capacity negatively. If you are running the coach engine (going down the road) and the alternator is supplying charge to the batteries that will effect the surge capability in a slightly positive way.

The compressor start should be approximately 300 milliseconds, with a soft starter like surestart or easy start that will increase that 300 milliseconds a bit, but no more than a max of 500 milliseconds (1/2 second), so that is why the surge capability of your inverter is what is important, not the running capacity.

I sell the SureStarts (so they are free to me) and have a 3000 watt victron inverter - but havent been inclined to put them on because it just doesn't make sense to me to worry about not running the generator going down the road. (Hell, usually if I have to run one roof air to keep the 40' bus cool, I need both of them to do that anyway)

As for running your AC off the batteries while boon-docking, if you look at the RLA on the AC, you will see even with a BUNCH of solar on the roof, the AC compressor will drag your house batteries down at a pretty ugly rate, making this impractical in our coaches. (FWIW, Tesla Powerwalls will not run an AC on their system unless the customer has three power-wall units minimum. And then they put a SureStart on each AC the client wants to run off the power-wall. (Yes, we sell the SureStarts to Tesla for their installs.))

On the other hand, putting two soft starters on a coach with two roof AC's might make some sense, because if you were careful about what else you had on your 120V load, you likely could run two roof airs on a single 30 AMP circuit. (I may get around to putting them on someday for that purpose.) The other veery good use case is if you want to run a single roof air off a Honda 2000i inverter generator, the easy start or Surestart will allow that to work no problem.

Let us know what your findings!

Re: Atwood 15K A/c unit

Reply #31 – August 17, 2019, 01:26:48 am

Quote from: Tim Fiedler – August 17, 2019, 01:03:02 am

I can't speak to the easy start, but I can speak to Sure Start performance. Look up the LRA (locked rotor amps) for the AC unit. With a Sure Start take that LRA value x .4 to get resulting LRA after installing Sure Start ( I suspect Easy Start is similar). We guarantee a 60% reduction in LRA with the Sure Start (usually closer to 65% reduction in the real world). So 60% lowering of LRA leaves 40% of the original LRA. Hence the equation of original LRA x .4 = New LRA after installing a soft starter.

The LRA is what will trip your inverter offline, after the unit is running the inverter will (very likely) easily handle the RLA (run load amps), but that is worth checking as well to be sure.

To calculate if your inverter will likely start the AC with EasyStart or SureStart, measure your "back-round" load (amps) when not running the AC on the inverter. Add the LRA amps to the back-round amps to get total (surge) amps. Take that amp value x 120 (your voltage) to get (surge) watts. See how close the "surge watts" are to your inverter surge watt capability and it will let you know if the inverter has a chance of starting the roof AC. IF your batteries are not at 100% that will effect the inverter surge amp capacity negatively. If you are running the coach engine (going down the road) and the alternator is supplying charge to the batteries that will effect the surge capability in a slightly positive way.

The compressor start should be approximately 300 milliseconds, with a soft starter like surestart or easy start that will increase that 300 milliseconds a bit, but no more than a max of 500 milliseconds (1/2 second), so that is why the surge capability of your inverter is what is important, not the running capacity.

I sell the SureStarts (so they are free to me) and have a 3000 watt victron inverter - but havent been inclined to put them on because it just doesn't make sense to me to worry about not running the generator going down the road. (Hell, usually if I have to run one roof air to keep the 40' bus cool, I need both of them to do that anyway)

As for running your AC off the batteries while boon-docking, if you look at the RLA on the AC, you will see even with a BUNCH of solar on the roof, the AC compressor will drag your house batteries down at a pretty ugly rate, making this impractical in our coaches. (FWIW, Tesla Powerwalls will not run an AC on their system unless the customer has three power-wall units minimum. And then they put a SureStart on each AC the client wants to run off the power-wall. (Yes, we sell the SureStarts to Tesla for their installs.))

On the other hand, putting two soft starters on a coach with two roof AC's might make some sense, because if you were careful about what else you had on your 120V load, you likely could run two roof airs on a single 30 AMP circuit. (I may get around to putting them on someday for that purpose.) The other veery good use case is if you want to run a single roof air off a Honda 2000i inverter generator, the easy start or Surestart will allow that to work no problem.

Let us know what your findings!

Tim, kind of hard to find a SureStart website, but when I did, it only mentioned 220 volt. Do you have a link for 110 volt models?
Sure Start SS1B08-16SN (8-16 RLA) – Ziller Electric
BTW, have ducted air over the cockpit on my coach, and if I close bathroom door, fwd ac will keep me pretty cool. Normally dash air will work okay, but when 95+ need the roof air.

Re: Atwood 15K A/c unit

Reply #32 – August 17, 2019, 01:43:27 am

Single Phase 115v (12-20 RLA) | sure-start

Re: Atwood 15K A/c unit

Reply #33 – August 17, 2019, 01:52:13 am

Quote from: Tim Fiedler – August 17, 2019, 01:43:27 am

Single Phase 115v (12-20 RLA) | sure-start

Thanks Tim, bit cheaper than the Easy Start, you need to step up the advertising budget.

Big market out there.

Re: Atwood 15K A/c unit

Reply #34 – August 20, 2019, 11:55:58 pm

Once we arrive to Florida this fall we are going to take the leap with the Furion AC. Supposedly they integrate well with the Dometic Thermostat.
John M.

Review of Furrion RV Air Conditioners - Standard Air Conditioner - FACR14SA-B...

Re: Atwood 15K A/c unit

Reply #35 – August 21, 2019, 08:38:59 am

Keep us informed, John. With the demise of Atwood, I am now very interested in these units. Hope they work well for you. I am most interested in how the control box for the a/c and Aqua Hot are integrated, and what, if any, wiring changes have to be made. Thanks

Re: Atwood 15K A/c unit

Reply #36 – August 21, 2019, 09:36:01 am

My only issue with Furrion was they have no heat.. The Atwood was pretty simple ( easier than I made it) and they work very well.. seem to cool and are quite.. Will test them next weekend at Zion for Labor day.. Integration was simple and they work as easy as the old Duo Therms

Re: Atwood 15K A/c unit

Reply #37 – August 21, 2019, 10:03:41 am

I'm thinking about getting one of those Atwoods before they disappear. Just one question: Do the regular covers like these fit or is it necessary to buy new ones? Thanks.
jor

Re: Atwood 15K A/c unit

Reply #38 – August 21, 2019, 10:46:45 am

Quote from: jor – August 21, 2019, 10:03:41 am

I'm thinking about getting one of those Atwoods before they disappear. Just one question: Do the regular covers like these fit or is it necessary to buy new ones? Thanks.
jor

Totally different

Re: Atwood 15K A/c unit

Reply #39 – August 21, 2019, 10:56:35 am

Quote from: jor – August 21, 2019, 10:03:41 am

I'm thinking about getting one of those Atwoods before they disappear. Just one question: Do the regular covers like these fit or is it necessary to buy new ones? Thanks.
jor

Photos of the Atwood shell in post linked below (Reply #16)

Help - Down AC in Desin Fl.

Re: Atwood 15K A/c unit

Reply #40 – August 21, 2019, 01:46:07 pm

Quote from: GleamB – August 21, 2019, 08:38:59 am

Keep us informed, John. With the demise of Atwood, I am now very interested in these units. Hope they work well for you. I am most interested in how the control box for the a/c and Aqua Hot are integrated, and what, if any, wiring changes have to be made. Thanks

Glenn,
If you check out the video on my previous post it shows you how it comes with the Dometic plug installed ready to be plugged in. They also make a unit with the Coleman setup. They also explain the specs and it looks like it already has the soft start built into the unit.
John M.

Re: Atwood 15K A/c unit

Reply #41 – August 21, 2019, 03:22:27 pm

Just ordered the Atwood. It's warmish down here and my two 22 year old A/Cs are running day and night. I'll be ready when one of them craps out. Kinda funny. This is actually the second one I've bought. A few years ago, during my short duration GMC ownership (six weeks) I bought one but I gave it to the guy that bought the GMC.
jor

Re: Atwood 15K A/c unit

Reply #42 – August 21, 2019, 03:40:20 pm

I much prefer the lowest possible profile and hope that the OEM 13K BTU units with heat pumps keep on keeping on. There are possible low profile replacement options, but the one that sounds best to me design wise and touted as being extremely quiet is seems ridiculously priced and not widely available.
Here is a link with some detail on the construction. It is a two fan unit and looks very well put together and supposedly 15db quieter than the typical unit, but they want close to 3K for them.
The Nuts and Bolts of the Quiet Air Conditioner - YouTube
Don

Re: Atwood 15K A/c unit

Reply #43 – August 21, 2019, 03:57:15 pm

Quote from: Don & Tys – August 21, 2019, 03:40:20 pm

...but they want close to 3K for them.

It's only money.

Can't take it with you.

He who dies with the most toys wins.

Feel better about it now?

Re: Atwood 15K A/c unit

Reply #44 – August 21, 2019, 04:04:23 pm

He he... Why not? Oh well, not an issue until one of these quit. Hoping that there will be more options by then. Besides, they are very short on the technical specs for these units (as in none!). I don't trust that what isn't explicitly stated doesn't matter.
Don

Quote from: Chuck & Jeannie – August 21, 2019, 03:57:15 pm

It's only money.

Can't take it with you.

He who dies with the most toys wins.

Feel better about it now?

Re: Atwood 15K A/c unit

Reply #45 – August 21, 2019, 05:10:45 pm

I am going to throw out a wild idea, maybe someone much more technical than I am will pick it up and run with it?
I have read some articles about using mini-split units in rv's, bus conversion, etc. Supposedly much better cooling, less noise, much less power consumption, etc. Seems like a winner except how/where to install the compressor which is separate from the inside unit. Reasonable costs too.

Just another thing to think about as our units get older and more things need replacing/upgrading.

Re: Atwood 15K A/c unit

Reply #46 – August 21, 2019, 05:38:16 pm

I ordered my Atwood directly from Dometic Corp. They told me that they have 200 units left. You will also need the control panel with remote control, much better in my opinion.

Re: Atwood 15K A/c unit

Reply #47 – August 21, 2019, 05:40:48 pm

Quote from: Ted & Karen – August 21, 2019, 05:10:45 pm

I am going to throw out a wild idea, maybe someone much more technical than I am will pick it up and run with it?
I have read some articles about using mini-split units in rv's, bus conversion, etc. Supposedly much better cooling, less noise, much less power consumption, etc. Seems like a winner except how/where to install the compressor which is separate from the inside unit. Reasonable costs too.

Just another thing to think about as our units get older and more things need replacing/upgrading.

I think the GV's are the only ones that you could make work because of the nose area to put the condenser. I think there was conversation in posts on it.

Re: Atwood 15K A/c unit

Reply #48 – August 21, 2019, 08:45:57 pm

Quote from: DavidS – August 21, 2019, 09:36:01 am

My only issue with Furrion was they have no heat.. The Atwood was pretty simple ( easier than I made it) and they work very well.. seem to cool and are quite.. Will test them next weekend at Zion for Labor day.. Integration was simple and they work as easy as the old Duo Therms

David,
Yes it would be nice to have the heat pumps but this forces me to use the Aqua Hot and not rely on the heat pumps.
John M

Re: Atwood 15K A/c unit

Reply #49 – August 21, 2019, 11:10:00 pm

The "Quiet RV Air Conditioner" from what I can find online is an Australian unit being imported and installed in a 120v version by Advanced RV in Cleveland. ($2700ish installed at their factory or $2100ish plus shipping and you install). Here are the specs on the unit from an Australian seller. Comes in 2 different models.

Houghton Belaire HB3200 Caravan Air conditioner - Pilgrims' Caravan & RV Parts

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