What's going on with my RV Air Conditioner?

What's going on with my RV Air Conditioner? In this week's tech tip, Todd tackles a unique and unexpected AC question from one of our viewers.
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[@breaking_bear]

I'm diggin the backwards hat look. It's a new energy.

[@johnbatzinger9203]

Interesting questions. One of the best parts of attending the fundamentals class at the NRVTA was the chance to ask specific questions like these and get the expert advice from Todd and other instructors.

[@WildBlueWanderers]

Ha, I was confused and the single shaft thing clicked in my mind at exactly the same time you said it. 😂 Scott

[@LoCleTXRV]

I would think that a RV roof shade would help to reduce the amount of wind going through the roof unit, and that should help.

[@SweetBabyFreezus]

Hey Todd!!! Thank you so much for answering my question!!! You are correct in that I am talking about my domestic ac’s. Since the fan is all one shaft that connects the condenser fan to the squirrel cage fan. I was thinking something similar to what you were saying. I was going to lay a piece a plywood down angled on the back of the unit so that it redirects the wind up and over the unit, so it doesn’t go through the condenser and spin the fan motor. And It shouldn’t cause any type of air blockage when the ac if running properly. I just wanted to ask the pro before I did anything like that. Thank you again!!! Hopefully I’ll see y’all down at the NRVTA in the next year or so.

[@dalestevens128]

Just leave the unit On high instead of auto. That way the fan is already turning in the right direction before the wind gust.

[@SweetBabyFreezus]

@@dalestevens128 that may be the route we have to take. Although I’d like to avoid that if possible. I don’t like paying electric bills already lol. Also that will cause me to have to clean the filter screen and evaporator coils more frequently than I already do. But if it comes to that, we may just have to. Thanks.

[@dalestevens128]

@@SweetBabyFreezus running continuously may not be much higher bill than you think. It takes a huge jolt of voltage to startup the unit. If the fan is already running, that eliminates that kick start. Also, with the continuous air movement inside the RV, AC (compressor) may not kick as much. Yes cleaning filters is more often but burning up the AC unit due to the current situation is much more costly. IMO

[@SweetBabyFreezus]

@@dalestevens128 true. I agree with ya there. When hooked up to shore power that is probably the best option.

[@scottharper1777]

Make lovers for the sides and the back. This way the "incoming" wind will not get in enough to spin the fan but will open when he fan kicks on and blows air out.

[@Augiebracerofam]

For the A/C wind blocker, I would recommend getting a large plastic storage bin and creatively remove portions to allow a slower controlled air flow. Some bungee cords or cargo straps to hold keep it from flying away. Thank you for sharing and have a great day.

[@RoadsofLife]

This is one of the BEST videos you've done... it answers a burning (or would that be cooling?) question we've had for a long time. Sending you an email with details! You Da (Bearded) Man! Be seeing you!

[@joesutterfield6113]

Leaving the fan in the on position will prevent the reverse rotation. They could use the automatic mode when home and run constant when gone.

[@docwil2541]

My suggestion on the first one is to make the air dam out of Kydex. It's really easy to form and work with. Doc

[@cruisinguy6024]

That’s not a bad idea but they’d definitely need to add some sort of balast to hold it down in 60MPH winds

[@SweetBabyFreezus]

@@docwil2541 I will definitely look into this. Thanks for the idea.

[@docwil2541]

@cruisinguy6024 you can mount it to the shell of the AC unit. Bolt on a couple of aluminum "arms" to give the stand-off needed. The whole thing can be removed quite easily for a travel day.

[@TimSpacek]

Peace out Brother! Love your content.

[@user-ky2rk2vl3t]

Great videos I enjoy them a lot. I wouldn’t recommend putting a big piece of plywood on the roof. A diverter 3 to 4 inches high behind the AC probably 3 to 4 feet back from the AC put a pool noodle or weatherstripping between the material that you put up there and the roof of the camper simple ratchet straps just be careful not to overtighten should be sufficient. It will work similar to a bug shield on an automobile divert the wind up without adding a lot of extra weight or something too much to grab the wind. Diverter can be made out of aluminum or plastic maybe attached to a piece of wood like a 2x4

[@miltonprice4250]

Leave fan on.

[@nathanurick8320]

@@miltonprice4250 Mr Price what will leaving the fan on do for me.

[@miltonprice4250]

@@nathanurick8320 in the story with fan turning backward because of wind gust, if it is left on it would be stay running in the right direction.

[@nathanurick8320]

@@miltonprice4250 I’m not an rv tech so maybe that’s why I don’t understand. My ac might run perfect for 8,10,15 or even 24 hours but then the next time it won’t last an hour.

[@billdavis2466]

Yes that is what I was thinking good call

[@nathanurick8320]

@@billdavis2466 bill can you explain why you think leaving the fan on will help. I just don’t understand why I would want the fan on. This is an air conditioner and I’m in Florida so I would much rather feel cold air.

[@stevesanders2972]

I saw the post from the person that asked about the AC issue and said it's a Dometic AC. Our RV has a Dometic Penguin II. It intakes are on the passenger and rear sides of the unit and exhausts it out the vents on the driver's side. So, if you attach some fabric over the exhaust vent so that it's well secured along the top and front edges and long enough to almost touch the roof. It needs to be able to be blown open when the fan is running to allow air out. However, when the fan isn't running, it can lay over the exhaust vents to prevent the wind from blowing in. I'm thinking a little rain fly material and some tie-wraps. Maybe some VHB tape too.

[@shanedenmark5536]

If the RV is in a permanent location and doesn’t ever roll down the road, disconnect the rooftop section and turn it 180° (kinda like Todd’s hat), resecure. Now when the wind hits it, it’s blowing the fan in the correct direction.

[@thomasbartlett694]

Also, put a bluetooth temp sensor in the RV to alert at a present temp. If its 83 inside in this situation what would happen if the power was out. This will give piece of mind for you about the temp for your dogs!!!!

[@SweetBabyFreezus]

We do have one of those. And I have my max air fans set to turn on at at a certain temp. But right now we work about 45 min away from the rv. This is the only time in 5 years of full timing that we have experienced anything like this.

[@cruisinguy6024]

A temperature sensor is a must for anyone that leaves dogs alone during the day in a hot climate, provided there’s internet connectivity for the right itself. A standalone Bluetooth sensor is useless when nobody is home as they connect directly to your phone, what’s needed is a WiFi or even LTE connected sensor, unless your RV had its own internet connection (such as a dedicated hot spot, mobile router, starlink, etc ) Twice in the past month on a sunny Texas day there was a multi hour outage in my area. Thankfully I had my dog with me already but I know many other pets in the RV park were locked inside hot RVs. 😢😢 Even if you have an internet connected temperature monitor it’s only useful if you’re within a reasonable distance of the RV so you can leave work / your activity to run back for the dogs. Last but not least those of us with triple AC rigs are probably used to tripping breakers in the summer. Even on a good weather day with no utility outage one can find their rig without power. The best way to advice this is to keep your plug and receptacle in good working condition by periodically checking the prongs and contacts, cleaning any corrosion, and ensuring the prongs are not bent. If all that is good and you’re still tripping a breaker it’s time to replace it, if you’re long term it’s good to keep a spare handy at all times.

[@SweetBabyFreezus]

@@cruisinguy6024 when this issue first came around, we ordered one of those waggle devices. It works well but when we work 45 min from home, there isn’t much we can do quickly. So I’m looking into a way to prevent this in the first place. We also have some cameras around as well, (interior and ring doorbell). So we will know when the power is out. But we don’t have an issue with the breaker tripping. Just the ac fan spinning in the reverse direction.

[@cruisinguy6024]

@@SweetBabyFreezus 45 minutes isn’t terrible, sure it won’t be comfortable inside but at least they won’t be in danger of a heat emergency. I think there’s one obvious solution for you that I’m surprised nobody has mentioned: simply change your AC from “auto cool” to “cool high” so the fan runs continuously while you’re gone. This sidesteps the issue completely so the winds won’t be able to spin your fan in reverse and thus stopping it from turning on in the correct direction as it’ll already be running the correct direction. There’s two major safety nets for RVers with pets in the summer: 1) generator with auto start capability. This is a huge advantage for obvious reasons. I have an onboard generator but currently it does not have an auto start capability 2) high end inverter setup with large battery bank, such as a Victron inverter with a lithium battery bank. My current system can run just one AC non stop for 4 hours (basically it was designed to be able to stay cool at night without the generator when remote / parking lot camping) but that’s definitely sufficient to keep my dog safe in the event of a power outage while I’m away. I’ve noticed some good tios in the comments about diverting the winds in your situation but the simplest and easiest method is to just keep the fan running. Just keep in mind if you build some sort of wind diverter it needs to stay put in those winds and not damage your roof membrane or the AC unit itself. I’d be concerned about using the roof unit as an anchor because they’re not designed to take that stress and if it rains there might not be enough pressure on the gasket to keep water out.

[@big53doin]

Hey Todd buddy….i want you to think on the second persons name 😂😂😂 they might have got you my friend… say it real slow!!! (Hint,hint) keep up the good work!! We Enjoy the videos

[@jamesmccutcheon3806]

I was thinking the same thing as he was reading it!😂

[@infinityvideoprod]

​@@jamesmccutcheon3806oh ya, I heard it too! Same as the "Dickens Cider Company". My wife really enjoys a good Dickens Cider! 😂😂😂

[@brucefilbert5758]

They make electric motor shaft brakes that are easy to install and they release when the call for the fan is received

[@exps01]

Hey, Todd and NRVTA gang! Love the tech tips. You've taught me a ton! I was hoping you could provide some tips on how to protect an RV interior when it's in storage and not connected to any power. I have to store my RV in a storage lot with no power, so I can't run a dehumidifier or have an AC set to keep humidity down. I live in the south (FL) so it's a concern. Any tips or things I should be doing to protect it? Thanks!

[@flyhunt]

Set up a 3 sided carport and that will keep the wind out

[@user-ef5nl4ys9p]

4 cinder blocks on top of a piece of plywood . . .

[@markmeier4206]

Thanks for the advice Todd! Unfortunately your advice on my "whisper quiet" ac hasn't helped but while up there everything seems fine. May have to pull the unit off and really dig in. But I did notice the compressor was really hot (to hot to touch) how hot is too hot for the compressor? Unfortunately I don't have a temp gun yet. But the lines were nice and cold.

[@TLec547]

Make sure the fan is on High all the time: don’t use the auto fan setting. It’s worth a shot.

[@billdavis2466]

Leave the fan in the on position and check the direction it will be hard with out taking the filter cover off Make shore it is not moving then start the fan then put the cover back Then leave the fan in the on positions The average users will not have to do this

[@toddkiernan]

An air dam was my thought, short of leaving the fan on like others below say. Having the fan on costs $ in electricity if they have to pay that. Also, unnecessary wear on the fan motor.

[@nathanurick8320]

My 15,000 Btu dometic ac is less than one month old and it’s freezing up. Yes the inside is taped up right keep hot air from cold. I’ve checked the amps many times and yes the amps are good. It may run 24 hours very good and then it might freeze in less than 2 hours.

[@allenpardon8211]

Wow, I just bought a 15k domatic. We haven’t even been able to try it out yet so hopefully he answers you

[@nathanurick8320]

@@allenpardon8211 Allen I was told 1 out of 6 right out of the box are bad. The bad part is either I take it back off the rv and take it to a dealer that works with dometic or I pay some rv tech to do it and that’s a shame. Dometic should send a tech to me but that’s the rv industry and it will only change if we stop buying rvs

[@danaguillot822]

What if they leave the fan on not auto ?

[@SweetBabyFreezus]

@@danaguillot822 that is absolutely an option. While we want to be a little more aware of our power consumption (I hate paying those electric bills lol) that may be the route we have to take. The winds in this area pop up out of nowhere sometimes and I don’t necessarily want the unit to run all the time if I don’t have to. I want to try and avoid that first.

[@slightlycrazy2nite]

Flapper door on backside of AC unit. Leave enough room so the wind can't block off air when wind is pushing against fan. The bad news is you will have to drill into the cover.

[@Iamk2jones]

Could they replace the domestic with another brand without that type squirrel cafe fan? Also he they replace their thermostat with the smart Microaire. That way they would be alerted to when it happens and they can remotely restart the system.

[@Brian-5150]

Would you be able to attach exhaust fan shutters to the condenser side?

[@Erutan409]

That's actually a decent idea. Only issue is that the wind might overpower the fan, still, and restrict air flow opening them. I'd make a wind block out of sheet metal that would wrap the exhaust, but offset by 6 inches. And then take your shutter idea and put that on that shroud. That way, the exhaust could exit, regardless of the wind force (positive or negative). You'd have to mount it to the camper, no matter what. But definitely remove it during travel.

[@jb1047]

I'm going to risk getting myself in trouble here. Questions regarding condenser fan: Doesn't condenser fan pull air through condenser coils?; Isn't hot air exhausted from both sides or top of the rooftop unit, depending on manufacturer/design?; Wouldn't air into face of condenser coil spin fan in normal direction?; Wouldn't wind have to come from both sides or top to spin fan in reverse? Questions regarding evap fan: Squirrel cage fan is centrifugal. Although designed for more efficient flow in preferred direction of rotation, won't air still flow regardless of rotation direction? Seems more likely to me that the severe wind could be resulting overcooling of refrigerant in condenser. Also sounds like the system may be a little undercharged. I'm completely willing to be educated if I'm thinking incorrectly. I'd love to see a video of the reverse rotation.

[@SweetBabyFreezus]

@@jb1047 I figured I would reply since it was my question that Todd addressed in the video. So I’ll answer a few of your questions. 1. I have the domestic brisk air 2 unit (2of them). This unit pulls the air from the side vents and blows the air out the back, through the condenser, to the outside of the unit. Essentially the fan pushes the air “out” through the condenser, and not pulling the air “in”. So the wind coming from the back, blowing through the condenser and into the unit is causing the fan to spin in reverse. 2. You are correct regarding the squirrel cage being centrifugal. But when spinning in the wrong direction, due to the orientation of the scoops on the inlet side of the fan, it pulls no air through the evaporator. When I put my hand up to feel the air, when it is spinning in the opposite direction, you don’t feel anything. Since no air is coming through the evaporator, it freezes. 3. This unit is a sealed system and there are no high and low pressure valves to check the refrigerant levels. Unless I were to have the lines tapped. Which is too much work for me. Essentially this is the first time I have had an issue with these units. I keep up with the maintenance and clean the coils every 3 months, since we are full timers and these things run a lot. If you would like me to make a video, I can do that over the next few weeks to try and explain further. Thanks for the questions. Cheers!

[@melissapeper4603]

I have a question, but it's not concerning the AC. I would like to know what would cause a trailer to catch on fire when nobody had been there for about a week? It's was just a pull behind travel trailer.

[@tomballard4794]

Something like window louvers?