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AC is blowing 35 dgrees at the register

Bowtiepower00

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all I did was fix divider, and remove the stock griles....(ducted ac)
I think I remember you posting these upgrades before, can you link to the post or repost what needs to be done? I need to get my new fiver fully 2FF approved. Any other tidbits or things to do or add that we can use to improve our trailers?

Also, I’ve seen you advocate for sumo springs on motor homes, have you ever used them on a trailer? Looking at them and lippert shock kits. The shock kits look like a PITA, but the sumos are pretty straightforward. Maybe they are unnecessary, but I’m just looking at options to make my rig tow as good as possible, it will definitely see some off-road time getting to campsites at glamis and around the southwest. Plan on keeping my rig for quite awhile.
 

2FORCEFULL

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I did R&D work with gerry at sumo... and set up the 18,000 lb and the E350 e450 RV's...... the sumos would work if you installed them when trailer was full loaded.. like a toy hauler... make sure yu get it loaded first..

as far as the ac's.... it's a dramatic drop in noise level getting rid of the plastic defussers, that and they are way too restrictive... which puts a load on the unit and cause less air flow..... I have no griles on right now... and left the stock cover on the unit.. on mone the units are front and rear so good air movement..
 

2FORCEFULL

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here's a guy that teaches how not to do stuff right...lol




first,... you take top layer off with the four corner screws, then llook to see if the duivider was adjusted proper... while the 3 screws are still holding the bottom layer... make a pencil mark where the return air section is.... never never never put the divider like this guy did blocking 20% of cooling side... the divider needs to go at the edge of the duct,... not covering... then if need be tape the edge on the divider on the bottom.... you can also see this was his first time because he tryed to put the bottom layer back with a corner screw.... you can see they deleted that whole section where it didn't work and all of a sudden the parts were on


but it does show what to look for... every newer rv ive owned i've had to fix this... most the time the piece is just laying up there..
 

mjc

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I found d this on another forum I follow and plan to do it to mine soon as I have time.
 

2FORCEFULL

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I found d this on another forum I follow and plan to do it to mine soon as I have time.
you could have found this years ago right here... i've been doing this mod for years... you can do it with a piece of sheet metal and get the same results...
 

Riverbound

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35 degree supply temp means you have a 20-30 degree coil……That’s not a good thing. As the coil is below freezing temp and will eventually ice up. 😳😳 normal supply temps should be in the 40-50s or in the 15-20 degree drop from return temps.

I have considered doing this mod to my units as you have posted about it a few times.
 

2FORCEFULL

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35 degree supply temp means you have a 20-30 degree coil……That’s not a good thing. As the coil is below freezing temp and will eventually ice up. 😳😳 normal supply temps should be in the 40-50s or in the 15-20 degree drop from return temps.

I have considered doing this mod to my units as you have posted about it a few times.
I cheeted a little.... my coach has metal ducts encased in foam... I took a reading from the sheet metal... it's my thought that those long metal ducts that are ice cold will sure help the little AC's to be wat more efficient

also there is a probe going into the evap to prevent freezing..
 

2FORCEFULL

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I can do this mod in about 15 min....tools needed in hand.... all you need is a #2 square bit... utility knife, and about 5 bucks worth of polar freeze foam from lowes...

also this is a good time to make sure you mounting bolts are snug... when done... you can't tell i did anything,... but.. neighbors will mention how much cooler it is in my coach... avrage,,, about a 20 degree drop in temp... my new black pusher looks cool,... and now it is in side....

I ony have 2 13,500 ac's... shacking my head at the bean counters that saved a few bucks doing that, then had the balls to put a 360k msrp on those rigs knowing that it will never work in the heat of summer... I tested with a DB meter... but forgot the results... but remember this... with ac's on.... barley hear the tv on max, after the mods,.. half volume...

the little round plastic reg vent cause most the noise,... and almost all the restriction... thor just keeps adding more of them to help air exchange...
 

2FORCEFULL

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I can do this mod in less than a beer... if anyone needs or wants this done , I would do it if you could video it and post it here
 

bagged97taco

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I did this and it worked out great. Can’t believe how bad the install job from the factory was. I was losing so much cold air into lost space due to the worst taping job I’ve seen.
 

2FORCEFULL

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heres another video , way over kill IMHO....but it shows the objective,,,, I could do 20 of the while he is fuc'n with all that foam and stuff..

and I personally think all those triangles don't do shit but decrease air flow..... I think in exhaust mode...you are not gonna increase air flow if the restriction is in the register's... like putting headers on a car with single 2'' exhaust.... the stock registers cut the hole down from 5'' to 4'' then even less with the diverters plugging up the hole....those long ducts will scavenge pull the air out of the box that feeds the dct work for the RV,,, that and filling the box with all that foam will have a neg effect IMO.... they make a tool to measure air pressure that you could use to see who's right and wrong here ... but the differance will be so min. that it's not worth checking

 

2FORCEFULL

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any thing you put in front of the forced air supply will cause back pressure to the motor fan... the fan would be more efficient with no duct at all..
 

2FORCEFULL

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anyway,... I have no way to post a pic or video right now so hard to explain.... but once you see what I do and how fast and easy it is... to get the same or better results... and still have beer money left... you might agree
 

2FORCEFULL

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35 degree supply temp means you have a 20-30 degree coil……That’s not a good thing. As the coil is below freezing temp and will eventually ice up. 😳😳 normal supply temps should be in the 40-50s or in the 15-20 degree drop from return temps.

I have considered doing this mod to my units as you have posted about it a few times.
here's a question for you as you are a professional in the trade.... don't ac units have a set requirement for sq in of service and return???? on my home builds I put return air in all the rooms... my homes you can't hear the air and hve no dead spots, cool down quicker even with bedroom doors closed..
 

Riverbound

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Yes you want to achieve 400cfm/ton. To figure out air flow of a register take length x width x 2.8

Example. A 10x30 grill will flow 840cfm. And that’s good for up to a 2 ton unit.

You really can’t oversized return air but supply air will have issues if not properly sized. Too big is as bad as too small.
 

Riverbound

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Yes you want to achieve 400cfm/ton. To figure out air flow of a register take length x width x 2.8

Example. A 10x30 grill will flow 840cfm. And that’s good for up to a 2 ton unit.

You really can’t oversized return air but supply air will have issues if not properly sized. Too big is as bad as too small.


Now to figure out the cfm needed per room.

It’s length x width for a standard 8’ ceiling.

So a 10x10 room is 140cfm.

For ceiling heights above 8’ you multiply
1.1 9’
1.2 10’
Etc etc.
 

SoCal_BT

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I tried the tape last year it did help but I was still losing air. This year I bought this styrofoam pc from these guys and it made a huge difference. I did lose the dump air future but the trailer is much colder. Waiting to see how it does when it gets really hot out here in Havasu but even at 100 outside it’s been real cold inside. Might want to check these guys out…

 

2FORCEFULL

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Now to figure out the cfm needed per room.

It’s length x width for a standard 8’ ceiling.

So a 10x10 room is 140cfm.

For ceiling heights above 8’ you multiply
1.1 9’
1.2 10’
Etc etc.
so doing math.... 1 ton = 12000 btu,.... a 13.5 btu is about 1.1 o1.2 tons.... a 32 x 10 is only 320 sq ft.... so a single unit should cool... but that leave out sun load for windows and such..... a single unit rv will cool at night.... but not during the day... so my theory is the way to get the most out of a unit is to get max air flow across the evap......????
 

Riverbound

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so doing math.... 1 ton = 12000 btu,.... a 13.5 btu is about 1.1 o1.2 tons.... a 32 x 10 is only 320 sq ft.... so a single unit should cool... but that leave out sun load for windows and such..... a single unit rv will cool at night.... but not during the day... so my theory is the way to get the most out of a unit is to get max air flow across the evap......????
To a point yes. But too much air across the coil doesn’t allow for proper heat absorption by the coil. Refrigeration is a cycle And all parts of this must be correct. Too much and too little of one thing will negatively affect the performance.

But like i stated above.near impossible to have too much return (air entering).
 

2FORCEFULL

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To a point yes. But too much air across the coil doesn’t allow for proper heat absorption by the coil. Refrigeration is a cycle And all parts of this must be correct. Too much and too little of one thing will negatively affect the performance.

But like i stated above.near impossible to have too much return (air entering).
have you looked inside a rv ac????? nothing they do makes sense
 

Dalton

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35 degree supply temp means you have a 20-30 degree coil……That’s not a good thing. As the coil is below freezing temp and will eventually ice up. 😳😳 normal supply temps should be in the 40-50s or in the 15-20 degree drop from return temps.

I have considered doing this mod to my units as you have posted about it a few times.

if hes using laser temp gun held at the supply, in my experience they keep dropping and dropping the closer and longer you hold them there.
 

Hardly Satisfied

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Great info now I’m going to look at my motorhome a/c and see what I need to do
 

Mondorally

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Thanks for the tip. Fixed mine yesterday - the divider was angled too far - had a 3/4” gap between the plenums. Not to mention the electrical junction box that had come off its mounts and was partially blocking the intake tract. Flow at the outlets is noticeably increased, and both cooler and quieter. Curios to try it when we get some heat outside as it had always struggled before. Thanks!
 

Mcob25rg

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Just got a 2022 A, 2 roof units. I’m having a hard time understanding the mods - would LOVE to see 2FF do a video. Steve, can you do a “list”, step by step - I might be able to follow that and get mine performing correctly
 

2FORCEFULL

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Just got a 2022 A, 2 roof units. I’m having a hard time understanding the mods - would LOVE to see 2FF do a video. Steve, can you do a “list”, step by step - I might be able to follow that and get mine performing correctly
watch the video on post #4
 

SoCalDave

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I tried the tape last year it did help but I was still losing air. This year I bought this styrofoam pc from these guys and it made a huge difference. I did lose the dump air future but the trailer is much colder. Waiting to see how it does when it gets really hot out here in Havasu but even at 100 outside it’s been real cold inside. Might want to check these guys out…

I looked at that option but couldn't see paying $170 for a piece of styrofoam so I followed what this guys did. I also noticed the the registers were leaking bad due to them not being taped well to the ducting. made a huge difference in cooling and db level.

 

2FORCEFULL

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well I spoke too soon on this one, my coach is a black 33' palazzo with a full wall slide and a bed room slide.... setting with the sun beating on the full wall,... it struggles to keep cool.. probley need another ac on the roof to get it in the low 70's... if I park it with the front headed to the morning sun it does better as the sun moves to the rear, that and if i can park where the sun goes over the top evenly,... changing the 13,500 to 15,000 btu wasn't worth the money,... very little improve ment..
 

2FORCEFULL

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also, didn't notice this till after I changed out the units,... the 13,500 and the 15,000 have the same size cfm fan motor... I think 320 cfm
 

SoCalDave

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Another thing I did and noticed a significant improvement on ducted systems is at the last register install a piece of foam in the duct just after the register. Not sure how well the ends of the duct are sealed but I felt I was loosing some air to the attic and it seemed to help on my unit.
 

amberkiza

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I noticed the the registers were leaking bad due to them not being taped well to the ducting. made a huge difference in cooling and db level.
Nox Vidmate VLC
 
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