Both 21 year-old roof ACs, Dometic Penguins, are dripping water into the coach, even after gently tightening the gasket, so I took the plunge and ordered:
- Dometic Brisk II Air heat pumps, model B59186.XX1C0
See Dometic Brisk II Air | Dometic (https://www.dometic.com/en-us/us/products/climate/air-conditioners/air-conditioners-for-rvs/dometic-brisk-ii-air-_-20678)
- Ceiling assembiles
- Thermostat, Comfort Control II
- Multi-zone control kit
A few questions:
What have I done? PPL Motorhomes was having a sale, so what's an avid Foretraveler to do?
Would the existing communication cable, 12V and 115VAC wiring and remote temperature sensor work?
Would this come with new gaskets?
Anyone want the old ACs?
How quiet are the new-generation AC units?
Any advice on this upgrade would be appreciated.
I have not changed out the units on our coach yet but have over the years changed out units on the other RV's I have owned and have helped friends, so
Yes 120v wire will work
they come with gasket.
LV wire will work on connecting up but may need a special board for them to talk. Seems every time we have done one, something had changed on the controls.
I had my units replaced about 18 months ago with the Penguin II heat pumps. They were able to use the existing 110 and 12 volt (telephone-type with modular plugs) wiring, as well as the remote temp sensor. All that was needed was setting some DIP switches correctly for the configuration.
These Penguin II units are a big disappointment in noise. With the compressor running in cooling mode they are substantially noisier than the old units and it gets even worse in heat pump mode. I understand that this might be the Penguin design so the brisk airs may be better.
The Dometic Brisk II Air marketing states:
- Less vibration and noise
- 30% more airflow
- NASA inspired
I believe their is a three-speed blower. However, the compressor noise may be louder than fan noise. We will see.
We're still using our original Penguins, so at the moment only asking out of curiosity (knock wood):
I have read that with the the "heat pump" style roof air conditioners, the air distribution fan has to run all the time the unit is turned on. Is this true for all brands and models? I always figured it is the fan vibration and noise that most people find annoying...at least with the older style A/C units. Just wondering if having the fan running all the time is objectionable.
Chuck, I have the Penguin 2's with the ccc thermostat, heat pump cycles fan on and off just like it does in ac mode.
One word: "YES". Maybe it's quieter in the coach, but it's obnoxious to neighbors! ::)
I purchase (2) Dometic Penguin II 15,000 BTU's heat pumps high capacity this year from PPL with the new CCC t-stat. It had everything needed to replace the old units including the base gaskets. Yes I believe they are a little louder with the fan speed on high but once the inside temps come down the unit switches to medium speed so it's not to bad.
But everyone ears are different so I took some readings of the old units to compare, see as follow;
Old unit were Dometic Penguin Heatpumps and using a downloaded decibel meter app on my phone and a airflow meter.
Nothing on-------42 decibel
Fan speed high --68 decibel - Airflow 410 cfm over the driver seat vent.
New units
Nothing on ------41 decibel
Low speed-------67 decibel - Airflow 400 cfm over the driver seat
Med speed-------68 decibel - Airfow 450 cfm
High speed-------71 decibel - Airflow 475cfm
Nothing on but generator - 56 decibel for comparison.
Two things that I consider was the ease on installation with existing wiring (telephone T-stat cable had to have new 4pin plugs crimp on) and components such as reusing the interior grill also being in Arizona I wanted the largest capacity for pull down and airflow and that's what I got. As an side note I made an baffle that fit into the discharge air plenum that better directed the airflow to the side ducts, by doing this it reduce the turbulence in the plenum box and thus reduce the noise an little.
Steve
I have 2 Atwood 15,000 btu units with heat. Outside the RV I can't even hear them running, Not too bad inside either.
Thanks for the replies. My Dometic Brisk II Air units have not shipped yet, but here are a few comments:
1. Quieter?
I guess Dometic can claim their air conditioner is quieter if it has just one decibel reduction in noise, which is almost imperceptible. Dometic's website states: "...great care has been taken to reduce operating noise: with the motor, compressor and evaporator bracketed together for vibration-free, quiet operation. Long copper lines and dual rubber bushings are also responsible for minimizing noise and vibration. Allowing you to enjoy comfortable temperatures in peace and quiet!"
This surprisingly gives away some trade secrets. With all the claims of being quieter, I should publish the "before" and "after" noise levels. I do not have a DB meter, but perhaps there is a good app for that.
2. Old Telephone Cord
I am not sure if the 21 year old telephone communication cord with the RJ11 connector will have enough of the six possible wires populated. It could be challenging to pull another cable through the coach.
Or maybe I'll get lucky and only need to replace the old connectors by crimping on new connector using the extra existing conductors?
In response to noise questions, we leave our fan on either low, medium, or high (not Auto) when using the Penguin II's. It's more like a "white noise" and we don't hear both the fan and compressor abruptly coming on in a quiet coach. We find that we don't have to raise and lower the TV volume every time fan turns on. Works for us, YMMV
Ed
I think it's 'brand dependent', as well. Our Carriers are whisper quiet, where our Colemans could wake the dead!
Now that Dometic owns Atwood, when they make the Air Command AC units compatible with the CCC control thermostat I will
think about changing my units.
I think most of us are in search of the quietest air conditioner. So which one is it?
I still have the original 1999 units but may be replacing the front 13.5kbtu unit soon. Probably upgrade to a 15kbtu.
Do the heat pumps blow cold or just cool?
Starts out cool then warms up as it goes.. 10 min its warm in the coach
Quiet inside does not mean quiet outside. Some of the new and improved AC units just move the noise to the outside of the coach where they annoy everyone within a half dozen spaces.
Newer Phaeton's with Coleman Mach 8 AC units are particularly annoying and because most of them are very dark colors the AC runs all day. The newer Cornerstone's are the same. Whatever ambiance there might have been is destroyed by these howlers.
Just had a Foretravel owner in my coach this week and, like ALL other visitors, he commented how much quieter my Attwood A/Cs were than his, 15,000 btu heat pumps.
Thanks again to Kemajohn for the heads up that steered me to these quiet A/Cs
Best & Quietest RV Air Conditioner of 2018 Reviews (https://mozaw.com/best-rv-air-conditioner/)
If you go with heat strips instead of heat pumps you won't have to listen to the compressor when in heat mode.
Also you won't have the valve to possibly have to repair that reverses the system between cool and heat.
And they will provide heat at the lower winter temperatures some of us encounter.
I don't believe heat strips are available on the high output (15000 BTU) penguin II units. Please correct me if I am wrong.
I replaced one of my units with penguin II which required replacing the 4 button wall thermostat and the control board on the old unit.
I am skeptical about the "Best RV AC" article. It's really just a link farm with company literature. There is no basis for the ranking, no comparison, no Decibel measurements. However, I did choose their top pick. After seeing their modern design improvements, I was sold. Two Brisk II Air units are enroute via freight.
I will review difference between the 21 year old units and the new ones.
Tim - did you happen to get decible readings before you took the old units off?
Dometic RV Air Conditioner Showcase - YouTube (https://youtu.be/Le0D6O857Gs)
Will watch your thread here Tim. Have the original AC units I believe. They don't cool much up front, and at high speed are pretty loud outside as well as inside. Will be replacing them at some point.
John, look at the comments below the youtube video. Not well received it seems.
Wish Foretravel had ducted them more forward to the drivers area.
The other issue I don't like is the condensation just runs off the roof, wish there was a better way of managing it. Right now, here in humid south Texas, a lot of water runs off the front of the coach, into the step.
With aqua hot, not sure why a heat pump is needed. But not all coaches have it so...
Thanks for your interest. I will make a video showing:
- Decibel readings, old Penguin 1 units, various locations
- Decibel readings, new Brisk II Air units, various locations
- Hook up of CC II thermostat
- High and low air flow settings
- Heat pump settings and Decibel readings
I just downloaded the top-rated IOS app for Decibel measurement, called SPLnFFT. Funny name, but it works great.
I think your the 99 has heat strips not heat pumps.
The old ACs have heat strips. The new Brisk II Air units I ordered have heat pumps, not heat strips. It was about $150 each more expensive , but they will be much more energy efficient than heat strips. Yes, heating will cause more wear on the compressor, but I heard that it is good to run the compressor monthly, like the generator, to keep the lubricant circulating.
Heat strips are about 5100 btu's max. Heat pump is about 12100 btu's for the same 14 amp draw. Well worth the extra money if you have to pay for your electricity. Heat pumps only good down to 45 f. or so but heat strips at 45 f. don't do too much and you will probably need your furnace anyway.
My guru buddy mentioned greatly decreased service life on heat pump a/c's.
Foretravels basic design was to have ultimate backups.
If the aqua hot or the propane furnaces die and the weather is below 40 degrees you will freeze witg heat pumps. Period.
I have used a/c heat strips at -30F. Straight manual control on the old Coleman roof airs. Separate from the house furnaces.
Appreciated at that temp that both systems worked at the same time.
Days long ago when rving was an adventure. Single pane windows. Mylar window roll up shades. Lined velvet draw drapes.
Fluorescent bulbs behind the valances. Wooden under cabinet lights. Three panel sliding side body windows. Opening center.
Have had 3 different coaches with original ac/heat pumps that were 15 to 20 years old. Did have to change out two reversing valve coils [$10 each]. Heat pump operation is the same as ac operation except reversed, so wear is the same either way you use it. In Texas we use air con. 8 months a year, and heat pumps 4 months a year.
If someone can stay warm at -30 F on only heat strips, they are a lot tougher than I am. Heat pumps are noisier [but about the same as ac mode] but at over twice the efficiency, worth it to me, unless at a campground where electricity is included, in which case I will use my little cube heaters or aqua-hot on electric.
Not heat strips only, both the strips and furnaces were necessary and a hair dryer to defog the windshield as little hot water came to the dash at minus 20 at 3am
Easy to extend gutter so gutter ac water drains more forward so it is not on awning & step. Also add plastic gutter extenders so water drains to ground without usually touching coach.
My furnaces ductwork is grossly undersized, my
older propane furnacea would only run about 8 minutes before the high limit switch would shut off the burner even at 15 degrees outside and 50 degrees in the coach. This sets up a viscous cycle as the discharge air temp would climb to 190 with horrible efficiency shut off burner but continue to run the fans bringing in cold air into the heat exchanger and cooling the coach. Coach furnace size was probably based on old RIVA standards or a rule of thumb bullshit number based on very little insulation and heating up a travel trailer in 30 minutes. Our coaches have decent insulation. New two stage rv furnaces are no help as it's only available on the 35 mbh model. If you want consistent, comfortable, efficient, and quieter heat consider downsizing the unit. I will be moving the smaller bedroom unit to the front of my coach and getting a smaller unit for the rear. Your worst case scenario should be 100% furnace run time in extreme conditions with the coach being a degree or two below your normal confort level.
Would this group recommend that I add heat strips, to give more flexibility on heating? I believe most home heat pumps have heat strips for when low temperatures make heat pumps inefficient, or even harmful to the compressor.
We've lived almost 40 years in our house in TX with a heat pump + resistance heat strips as our cooling and heating source. Has always done the job just fine with our relatively mild temps. Down to 40 degres, we leave the system in AUTO and it cools/heats as necessary. Below 40 degrees or in sleet/snow conditions, I switch to the AUX heat setting, which uses the heat strips + indoor air handler to circulate the air, but shuts off the outside compressor unit. The heat strips probably draw a lot of power, but I think cutting off the outside (dual) compressor unit saves power, so overall pretty much a wash in terms of power usage.
Our coach still has the original Penguin units which (I think) are not heat pumps, but do have heat strips. They can be used as heaters much the same as our house system, since the compressor (I think) does not run in HEAT mode, but the fan motor does. However, we don't like listening to the roof unit fans running all the time, so we choose to not use them as heaters.
Instead, we prefer using several small electric space heaters scattered around the coach to provide (relatively) quiet heat where we need it. If they are insufficient, then the original propane space heaters come on to take up the slack. If we are dry camping, of course, the propane heaters do all our heating. This works for us, but we normally only camp in fairly mild conditions so we never see really challenging COLD temps.
Tim,
I would add the heat strips.
A lot of parks charge more for a 50A site.
I would run the front unit on electric heat all night and set both thermostats at 60 for the night. Comfortable up front in the morning.
Phred I am very interested in your results when you upgrade the heating system on your ORED. The design turns on the fan first in case of a gas leak then the flame then when it reaches its temp setting the flame cuts off and the fan stays on till the furnace cools off.
Not sure any resizing would alter that particular feature. The short cycling is annoying although.
In ultra cold weather the furnace's btu seemed to be closer to correct. Obviously not optimal for normal cool conditions
Have never seen a rv ac/heat pump with heat strips as well, if you do find one, you will need to do some thermostat modifications to handle the extra element. Why don't you just get the ac/heat pump and a couple of walmart cube heaters for when it is too cold for the heat pump? The penguin 2 has a circuit that prevents operation when too cold so you cannot damage the compressor.
A few questions:
1. Don't most home heat pumps have heat strips that automatically engage below freezing?
2. Why don't most RVs have this feature?
3. The Dometic Brisk II Air may have a feature which turns on the furnace, or am I reading the manual wrong?
Here is an excerpt:
"If system includes a gas furnace, route two 18 gauge thermostat wires from the furnace to the roof opening of the unit that will control it. If more than one furnace is to be used, route the second set of thermostat wires to the second unit."
Attached are the dip switch settings, which include:
Heat strip
Heat pump
Furnace / Aquahot
It's not clear if:
1. Can both heat pump and heat strip can be set?
2. Can the logic in the control module handle turning on a heat strip or fuirnace , or both below the heat pump's cut-out temperature?
Looks like a either/or, type of setting. Who makes the rv ac/heat pump with a heat strip?
I have lived with a heat pump since 1979. There are also 20KW of electric strips in the furnace. What they do is if the unit is in heat pump mode and the outside unit freezes up, it will go back to the AC mode to defrost the outside coils and will turn on the heat strips to compensate for the cold air on the inside. When it get colder then what the heat pump can handle it will then turn on the heat strips.
Had the same setup on my house in Arkansas except return air duct ran under and behind the fireplace so that the air would be preheated before it got to the air handler, if you had a fire going.
This is the way our home setup works. However, I have found that built-in "trigger" temp for
automatically turning on the heat strips is lower than I like. If I wait for the heat strips to come on automatically, the heat pump will be running the outside compressor(s) almost continuously trying to maintain the inside temperature, and they will, like you said, be freezing up repeatedly. I avoid this situation by
manually switching to the "heat strip mode". I don't know if there is a way to adjust the temp at which the heat strips are automatically engaged - guess I should research that.
Our furnace has a few covered plenum exit openings that we uncovered and ran short furnace hoses out into the room which eliminated all high limit shutdowns. Most are not aware that they cycle on high limit. Be glad you are aware and can do something about it.
Seen the extra holes. Never thought about more runs
Yes the plenum has extra holes, and some of those holes are almost completely blocked by the internal heat exchanger tubes. Took a saw and cut the bedroom unit wood enclosure on the inboard side of my coach and eliminated 2 nasty bends in the supply duct. Relocated the starboard aft facing bedroom outlet inboard also (old hole with additional grille is now return air) this also eliminated 2 nasty bends in they supply duct. My Rear furnace is much quieter now, doesn't cycle on high limit, and is more efficient.
Being a HVAC engineer I am kinda anal about this sorta thing. Spent a night in the coach when it was in the low 30's worked great, slept well. Still think I will move the smaller rear furnace to the front of the coach and buy an even smaller unit for the rear for better comfort. Will make Christmas and Thanksgiving trips to the relative's in the KS/MO area more pleasant. WTH even a ski trip to CO.
Foretravel and I needed you way back when. Never found anyone with enough expertise to re engineer that part of the coach you have now.
One of two ACs are functional, so these are preliminary results. Both Brisk II Air units have been installed along with a new thermostat, the Comfort Control II.
PROS
- Blows ice cold
- No compressor noise from AC
- About 5dB quieter. This is a preliminary result with only one AC running. See attached sound meter screenshot.
- Control kit is somewhat Plug and Play: The 12VDC supply wires had to be validated and the DC ground wire had to be custom-made with crimp terminals. The control kit had to be positioned so that the existing RJ11 control cable could reach.
CONS
- Noise
An annoying 30HZ booming noise is heard in the front and rear of the coach. I am not sure if it is caused by ductwork acoustic/pneumatic resonance or blower vibration. The noise is not heard in the center of the coach.
- Noise
Low-fan setting almost as loud as high-fan. My guess is that Dometic engineering determined that the compressor would freeze up is the fan speed was too low.
- Not DIY friendly
Dometic does not encourage DIY installs because there are no paper manuals. Even the online install guide is lacking full hookup instructions. The outdoor temperature sensor hookup was not mentioned. The thermostat displayed an E4 error "Outdoor temp sensor disconnected" but I figured it out after 1 hour of research.
- Lack of hookup instructions
One multi-zone control kit is required per AC. I only ordered one, so another control box is on order. See part numbers below. The control kit allows programming via DIP switch of your setup: two zones, heat pump, etc...
- Restricted return air flow
Control kit is packaged in a 6x6 inch metal box that is mounted so that it obstructs about 25% of the return air inlet. I am searching for a remedy to this obstruction. The remedy may be re-mounting the box with stand-offs from the inlet filter to provide better air flow. Maybe this is causing the booming sound? The documentation is poor, and allows some flexibility and customizing of the control kit mounting location.
- Bowed template
Torqueing the ceiling template (the metal structure that holds the AC and gasket down to the roof) to 3.5 ft-pounds caused it bow. It should have been designed with more and stronger steel.
Final results are in. Dissapointing. The new ACs are only about 5dB quieter on the low fan setting. They are about the same noise level on the high fan.
Here is the table:
NOISE COMPARISON TABLE, 1997 PENGUINE I vs 2018 BRISK II AIR 15,000BTU AIR CONDITIONER
LOCATION OLD AC NEW AC DIFFERENCE (db)
Couch 55 51 -4
Bath 63 58 -5
Bed 54 47 -7
AVERAGE -5
Note: Noise levels are rounded to nearest dB.
Some caveats:
1. The new ACs have up to 25% more airflow on high fan.
2. The new AC's noise is all fan noise, no annoying compressor hum.
3. No 'clunking' sound when the compressor starts and stops.
4. As mentioned before, there is an annoying 30HZ acoustic wave at regular locations throughout the rig. This may not be the AC's fault, but rather Foretravel's duct design.
5. To resolve the issue of return airflow interference with the control box, I pared down the box with tin snips and sheet metal formers. This allowed the box to be rotated 90 degrees, reducing the return air duct frontal surface area by 400% (16 vs 64 sq-in). What was Dometic thinking when they designed a huge control box that had to be fit inside the return air duct?
6. It's too bad the low fan setting is not as quiet as expected. Dometic should have a complaint files against them.
Would I do it again? Yes. Here are the reasons:
1. The old air-conditioners were leaking. There was caulking applied to the condensate pan, which was leaking. Someone also applied huge amount of caulk to the large 14x14 gaskets long ago, so torquing the four gasket bolts would not stop any leaking.
2. The heat pump is 2x more energy effieient than a heat strip. I care about saving money and the environment.
3. It's quieter, although marginally.
Methinks the Gentleman damns with faint praise. I hope we are not faced with the A/C replacement conundrum anytime soon!
What ya doing with the old ones?
https://www.youtube.com/watch?v=uCnsw9oRDsM
5 db is quite a difference. [to my old ears anyway]
You cannot Force 25% more airflow thru a duct system that was inadequate in the first place. Tim and others are correct it's air turbulence noise.. No magic fix here or anywhere else. Bigger units will make matters worse
Two replies.
1. Two old Penguin ACs are for sale for local pickup near the Pottstown, PA area. $50 each.
2. Our rigs are Hemholtz Resonators, causing that Booming sound. See attachment.
Example: Blowing over a bottle. The AC is the air source and our rigs are the resonance chambers.
Solution: I may experiment with reducing the booming sound by:
a. Design an anti-acoustic resonator chamber and install it out a window.
b. Modify the ductwork.
c. Close sliding doors.
d. Add dampening material.
So we who have no ducts can fit larger capacity units without suffering this booming noise? Extra points to the older coaches!
Sorry, but ducts or no ducts, we all travel in a big chamber with roof ACs that have a "neck' type air blower. Perhaps this is a case for a mini-split system, where the air handler is contained inside the rig.
As long as your happy with them Tim, thats all that matters. I agree that 5 db is some reduction, nothing to write home about, but I would take it. Lets hope you have more longevity with these units than others seem to have had.
Think its worth going with a 15000 btu unit if you have ducted air and need to replace your 13500 btu units. Only 10% more cooling, but unless really warm, you might be able to run only your back unit when sitting up front, and only your front unit when you go to bed. You do have to leave your bath/bedroom doors open a little bit to allow for return air flow. Little more flexibility in picking campgrounds because you probably can get by on just 30 amps.
10db reduction is a 50% reduction in perceived sound. 5db should be quite noticeable
You can always open the vent under the ac just a little for airflow..Sorry but for me, larger is better when it comes to the AC
"You can always open the vent under the ac just a little for airflow..Sorry but for me, larger is better when it comes to the AC"
Obviously if you need two ac's, you should run 2 ac's. but found that that "max cooling vent" on the bottom of the ac was a source of considerable noise even when closed, and air was going to the smaller vents. I cut a piece of reflectix and attached with double sided tape.
Maybe subjective, but seems quieter to me.
In Houston, Texas we have to worry about humidity. If your ac unit is too big, the unit will not run long enough to lower the humidity
Good idea about reducing noise caused by turbulent airflow around the cheap plastic diverter.
There is a lot of noise coming from this diverter because the full force of high-speed, 350 CFM air is being directed at it from the AC cool-air discharge duct. The diverter is molded on, so it can be overlayed with a piece of sheet metal that could be designed as an air splitter shaped like a curved inverted Vee. with, which would:
1. Smooth the airflow
2. Redirect airflow 90 degrees to the U270 ducts
3. Deaden noise
Give me some time and I'll experiment with this idea.
I discovered on my 15K Penguin in that when the fan was in high speed it put out quite a bit more CFM than the old unit, also my sound meter measured an average 74 decibel. The airflow was high enough that I believe cause turbulence in banging off on the closed supply grill. I made an baffle (curved V Shape) that fitted into the small supplied plenum that spilt that airflow by directing it into each ducting opening. Sound meter went to 67 decibel and drop to 64 decibel in second speed after pull down.
Steve
Steve, did you replace the supply grill after installing the baffle or use a piece of aluminum as Tim suggested?
Shape an inverted curved diverter out of open cell flexible limp foam. At the speed of sound, it doesn't like to change directions. Low freq attenuation is really tough once you produce the noise. These units beat the air into submission by ultra compact design and fixed standardized roof opening size. Room for a small hemholtz chambers on the sides of the fan scrolls maybe, but I don't think that's where the sound is generated. It's velocity and turbulence generated past the roof unit due to the airflow CFM. Kill some CFM and kill some noise. Until the coil freezes, and you pay for removing too much moisture.
It's slightly louder with the new diverters. My hypothesisis is that the ACs are pumping out slightly more air, which makes the air exiting the ducts louder. Attached is a photo of the one AC cover with a diverter, one without, and the dB reading in the bedroom with the door closed.
I would recommend not doing this modification.
TABLE OF DECIBEL READINGS BEFORE AND AFTER INSERTING A SPLITTER IN THE OUTLET DUCTS OF TWO DOMETIC BRISK II AIR CONDITIONER IN A 1997 U270
SPLITTER
LOCATION BEFORE AFTER DIFFERENCE (db)
Couch 51 53 +2
Bath 58 60 +2
Bed 47 49 +2
AVERAGE +2
Two possible positives:
1. The dB readings may be within a margin of error for the app.
2. There may be a slight improvement in efficiency.
There is no change in the Hemholtz resonance. On high fan, the 30HZ vibration is quite pronounced at regular locations throughout the rig.
Thanks for putting up with my project.
Having used the Atwood unit with 2 separate fan motors for the condenser and evaporator for a few months now, I think the noises you are complaining about are endemic to Dometic's use of a single motor for both fans. It is unlikely that Dometic puts much effort into balancing out the two fan blades and I think that is what causes the problems you are referring to. The Atwood units don't have the low frequency vibrations that you are talking about (my old Penguin units did though).
Noise on my Penguin 2 appeared to be coming from turbulence from the air from the blower directly hitting the irregular surface of the "max cooling vent". Rather than try to make a diverter, I cut a piece of 1/2" plywood and sealed it in place above this vent. Air from the blower now hits the piece of smooth plywood and is directed into the left and right vent plenums with little obstructions. I have lost the use of this vent, but because it allowed most of the cooled air to exit into the coach at a single point, it really did not allow even cooling. Noise from 3 ft below ac at low speed went from 67 to 58 db. Not a very sophisticated mod., but can now turn tv volume down from 80% to 30%.
Nice fix Jim. I like your overall setup. 4 AGM's? Solar max helps, what alternator do you run with this setup?
Thanks Bob, still running the LN160, but with the big solar, don't worry too much about engine charging. Am considering wiring the fwd ac [with easystart] into inverter panel, to see if I can use it running down the road without using gen. Probably okay when sunny, but might be pushing it if no sun. Did dump the isolator and use a battery combiner.
Old bird ran everything through the double inverters.
Ac's would come on on battery. Couple of hours in testing.
I ran a similar load for several hours to test everything on a run into Vegas. Gauges moved a lot when the convection oven came on. Three 8G8d's rebuilt 160 LN.
Combiner on. Batteries up. Convection oven on. Chest freezer on. 13.5 driving. Big drop when the oven cut in.
May have had the refer plugged in to the inverter side of the plug also for more load,
Gauges will jump around. Settled down in a minute or two, nothing blew.
Magnum 2812. True 3000 watt.
I would not try this with a 2200 watt inverter.
The 30HZ Hemholtz resonance also happens when rolling down the road over 20MPH with the windows open. I should design an air scoop to resolve this. It would equalize the low pressure waves created by the open windows.
Last I heard it was more economical to run a vehicles a/c then with the windows open pretty broad stupity statement. Location, location, location. 30 hz - 35 hz of design at 60 hz are typically tuned out of rotating equipmentt running on variable frequency drives due to destructive resonate forces. Beyond my expertise.
BTUs ARE DIFFERENT!!! DARN!!!
Oh, what can I say, I was comparing apples with oranges, sort of. The old Penguin unit was 13,500 BTU. The new Brisk II is 15,000 BTU, an 11% increase. So, nevermind the dB noise readings. By actually reading the specs, I could have saved (in my SWAG estimate):
- Money: about $600
- Weight: about 20lb
- Noise: about 5db
- Short-cycling of the compressor: bad
- Embarassment in a public forum
Live and learn.
On the plus side:
1. With global warming, if outside temperature ever reaches 120 degrees, this U270 will handle it.
2. The dB readings are impressive: it's about 5db quieter with 11% more BTUs.
3. One AC can cool the rig most of the time. So the short-cycling issue is mitigated. I will manually manage this by turning off the front and rear units based on their run time.