Cruisair Not Working Right

[rff105]

I talked with Johnny at AAP, he is out on medical leave but they gave me his cell phone. My tech is coming this afternoon and Johnny is going to talk him though the correct pressure setup. I'll let you know how it goes. They are only about 3.5 hours away but Johnny will not be back to work until mid Sept. I may take a trip down if i do not get it sorted out today, thanks for the refrence.

[GDeen]

Bill and Fred are also with AAP and know the cruiseair systems. I just went through a compressor change out in one of mine, and they were both very helpful. My guy didn't know cruiseairs, but we got the return line "beer cold" and all is well. I am seeing about an 18 deg differential on the unit which is good.

[Sawbonz]

Hijack alert!

We just spent our first weekend in ours since picking it up. The rear CruiseAir seemed to need to be set several degrees lower than the other units, but blew cold at that point. I didn't measure any temps, and just now emailed Troy to see if he can tell me where the returns are so that I can clean filters.

Is it too much to expect to keep all units on the same temp setting?

Is it unusual to have the rear units not cool down the bedroom enough when the door to the salon is closed?

[Jon Wehrenberg]

This is personal experience only so take it for what it is worth.

Based on where my units are I set each for slightly different temps so the interior of the coach feels at a uniform temperature. That may be because the front with its abundance of glass needs a different setting than a midship unit. It may also be because the relationship of the return air to the supply air is such that the SMX control needs a different setting because on one some of the chilled air is being returned and on another the return air is less affected by the supply air.

Also, keep in mind our SMX units can be calibrated and it might be each has been calibrated slightly differently.

Going further without looking at the data such as the temperature spread between supply and retunr air it is unknown if the units are working to the same level of efficiency, and if not that would also impact their set point to maintain comfortable temps.

As to the question about the aft unit cooling the bedroom with the door closed you don't mention if the engine has been running or if there are any other factors which will impact that unit's ability to cool.

If you measure the temperature spread on all your units you answer in part a lot of what you are quesitoning. You know immediately if your units are working properly. Then since the thermostat sensors are likely in the return air flow you can measure the temperature at which point the units cycle, compare their respective set points and temperature readings and you will know if the calibration is correct. If not recalibrate the temperatures. Then you have to look at variables such is sun pouring in through the front windows? Has the engine been running, is supply air being drawn back through the return? Are the filters clean?

If you use an IR gun, then as Jack suggests you can get a sense of the operation of the units by getting the suction line temps (the line that is at the condenser and is sweating). If they are wildly variable you can probably assume you need to adjust the R-22 Freon charge to maximize the efficiency.

There are so many variables and data reference points the best place to start is by making sure the basics are known and are correct. The temperature may be 75 degrees, but the Cruise Air control might be seeing that as 70 degrees and obviously that shuts the unit down prematurely so pull out the book and the IR gun and start with some good temperature checks and calibrations if required. Unless you have done the calibrations you are trusting they are correct.

[Gary Carmichael]

Who is AAP and where in VA are they located?

[Jon Wehrenberg]

They make the Cruise Airs. Now owned by Dometic I believe. I think they are from Virginia. You should have their contact info in your owner's manual.

I assume you are going to Austin. You will get a personal delivery of your stands.

[Sawbonz]

This is personal experience only so take it for what it is worth.

Based on where my units are I set each for slightly different temps so the interior of the coach feels at a uniform temperature. That may be because the front with its abundance of glass needs a different setting than a midship unit. It may also be because the relationship of the return air to the supply air is such that the SMX control needs a different setting because on one some of the chilled air is being returned and on another the return air is less affected by the supply air.

Also, keep in mind our SMX units can be calibrated and it might be each has been calibrated slightly differently.

Going further without looking at the data such as the temperature spread between supply and retunr air it is unknown if the units are working to the same level of efficiency, and if not that would also impact their set point to maintain comfortable temps.

As to the question about the aft unit cooling the bedroom with the door closed you don't mention if the engine has been running or if there are any other factors which will impact that unit's ability to cool.

If you measure the temperature spread on all your units you answer in part a lot of what you are quesitoning. You know immediately if your units are working properly. Then since the thermostat sensors are likely in the return air flow you can measure the temperature at which point the units cycle, compare their respective set points and temperature readings and you will know if the calibration is correct. If not recalibrate the temperatures. Then you have to look at variables such is sun pouring in through the front windows? Has the engine been running, is supply air being drawn back through the return? Are the filters clean?

If you use an IR gun, then as Jack suggests you can get a sense of the operation of the units by getting the suction line temps (the line that is at the condenser and is sweating). If they are wildly variable you can probably assume you need to adjust the R-22 Freon charge to maximize the efficiency.

There are so many variables and data reference points the best place to start is by making sure the basics are known and are correct. The temperature may be 75 degrees, but the Cruise Air control might be seeing that as 70 degrees and obviously that shuts the unit down prematurely so pull out the book and the IR gun and start with some good temperature checks and calibrations if required. Unless you have done the calibrations you are trusting they are correct.

That helps a lot. The bus has been parked for a couple weeks, so no engine heat. We had the doors closed because of the kids, but at 72 it wasn't cool enough, even though it never shut off. At 69 it was better, but that seemed really low. When we picked it up the tech calibrated the units, so it SHOULD be right after this short of a time.

I need to find where the filters are, as we missed that during the demo. I have an IR gun, and need to put it to work. As to those lines, perhaps someone will show me in Austin.

[jack14r]

Karl,The Cruise air manual it has the info on how to adjust the controls on the SMX controller,also look for louvred panels usually below the cruise air vents,these are held in place by 4 of the cabinet latches and they pull straight out and you will find the filter behind there just in front of the evaporator.

[Sawbonz]

Great, thanks Jack. I wish I could tag this post for later quick reference, since I can't back to the rig before we leave for Austin.

[garyde]

The filters on my Coach are;
1.Bedrom; back closet, port side, behind white panel.
2.mid-coach; Pantry clset; remove bottom shelf
3. Galley;wall vents by dining seat; grill vent pulls out

Once you remove the panels, shelf, or grill, you have to kind of reach in and fumble around for the filter. Its a washable filter.

The front a/c ; just remove the bottom vent cover at the front step a/c unit.