Hot nights and even hotter days in Mount Rushmore Florida!

[G_Hage]

Our 2008, or is it a 2006? Mount Rushmore ain't getting it in the keeping us cool and comfy department so far in center Florida, and it ain't even summer yet. Dealer checked rear A/C (blowing @ 55 degrees) and front (blowing @ 52 degrees) before walk through inspection for delivery. Been in it a day and a half and can't cool main living area below 78 degrees during daylight hours. Plus at 78 main unit won't even cycle (note: fan is in auto mode). It's not hot on central Florida yet. God help us this summer!!! We are only asking for 73-74!

We're told its a 2008 as per the title, yet the "Manufactured by Heartland" sticker on the pin box shows a 2006 build date, So I'm not even sure which insulation I have if there was a difference from 2006-2008.

With 15,000 btu rear (at least that's what I'm told) and 13,500 btu front, both blowing cool to the touch, should the MR be this hard to cool? I reeeally hope there is a fix to this cause if not its gonna be a problem to live in during the summer months.

Suggestions and remedies would be greatly appreciated to save this RM!

 

[cookie]

Are you running the fan on high? If not, or if humidity is high you may have a frozen coil.
Pull the cover that is on the ceiling and take a look for ice.
Are the filters clean?
What is the outside temp?
I see that you have slide awnings, that should help you out.
If both AC units are working properly you should be plenty cool.
Peace
Dave

 

[G_Hage]

Not seeing icing on the coil. Filter is brand new. Not sure if fan on high, wife operates the control cause I'm to blind to see. God that's a scary thought "he's to blind to see the A/C control and he drives an eighteen wheeler!" LOL

I think I'm gonna have both units serviced by an A/C tech to see if all is well and full of refrigerant.

 

[TandT]

I would say something is not working correctly. As you said, I would recommend having an A/C tech check your units for you.

We are frequently in 100+ degree temps in summer and we have no trouble keeping our BH 25+ degrees cooler than the ambient outdoor temperature. We are usually in a drier climate which may help a little.

We do have dual pane windows and during extreme heat 100+ we will sometimes put foil insulation in the windows

FWIW, we usually don't even run one air until the indoor temps reach 82 degrees or more. Second air starts getting work above about 90 degrees or so. Trace

 

[hoefler]

You have a 20* drop across the coil, it is working. Humidity is a killer!! Our 06 cools well with the 15,000 and the 13,500 in the bedroom. Thing is, you have no shade, which helps tremendously. With that said, we have been able to maintain 72* in 108* heat on asphalt and direct sun, Tunica Ms. in July. If the rig has been closed up during the heat of the day, it will take some time to cool down. Also, if you have had it open for extended amount of time with no climate control, ( like sitting on the dealers lot ), the humidity has saturated the rig. As long as you have a stream of water running off the roof and you have a greater than 20* difference from between the return are and the outlets, it is working as hard as it can. One other thing, DON'T shut the A/C's off and open the windows because it is nice in the morning! That is the worse thing you can do. The A/C's will not stand a chance.

 

[jbeletti]

No change in insulation in the Landmark by model year with the exception of the last few years, the additional of the Reflective material in slide room floors and front cap.

Email me your VIN and I'll confirm your model year so you can put that to rest, regardless of what paperwork says.

Jim

 

[jbeletti]

Do you feel that you have decent velocity of air coming out of the AC registers?

Note that the bedroom unit is not ducted - it's down draft only.

The main unit is ducted through-out. May be time to reflash the plenum area. Also may want to consider the home brew mod referred around here as the TimK "tent in a vent" modification. Start with checking volume, then consider checking the plenum flashing.

The other advice you've received here is accurate in what to expect from RV ACs in terms of the delta from outdoor ambient to what they can do inside the coach.

 

[danemayer]

Hi G_Hage,

We are only asking for 73-74!

You should be able to get this in the bedroom without difficulty. In the rear of the coach, you may have trouble. On these bigger coaches like our Rushmores, the additional length and the living area with slidesouts on both sides can be a challenge for the A/C unit.

At our last North American Rally, the Dometic Rep explained that Dometic expects an 18-20 degree differential between the air coming out of the A/C dump vent and the air temp in the rear corner of the rig. So if your A/C unit puts out 55 degree air, the rear corner could get to the 73-75 degree range in a best case. That sounds pretty normal by the way.

I've found that if direct afternoon sun is hitting the living room windows on either side, it's very hard to get to and maintain 73-75. There's just too much heat from the direct sun. Blocking the sun will help - a lot.

That said, if you get ahead of the afternoon temps by cooling the unit in the morning, to as low a temp as possible, the A/C will do much better in the afternoon. I'll also turn on the bedroom A/C and direct the air toward the hallway, while setting the living area thermostat very low so it keeps the living room A/C on max despite the bedroom cold air hitting the hallway thermostat.

Also, if you block the bedroom A/C ceiling vents during the daytime, more air will flow to the living room. We open them at night and turn off the bedroom A/C.

Finally, many of us have improved A/C airflow with a fairly easy modification - here's a link. The 1st post has the document with instructions.