roof air or basement

[pump-dump-go]

Howdy, been busy searching for good used ("our first class A") motorhomes, and finding a lot of good floor plans, mostly with slides.
Some Ford, some Chevy, and some diesel, and all in good shape with good prices. So I stop rambling on, here is my question.
Roof top ac, or basement h/a, pro and cons, noise levels.
Common sense tells me no units on top, lower roof clearance, less chance of roof leaks, but would like to know what others have experienced.
Thanks in advance

[MeanderMan]

I've had both roof and basement and much prefer the basement air. In the living area, there is no noise except the whisper of air through the ceiling ducts. Ours, like most, is not under the bed, and if anything helps us sleep as it provides a "white noise". The main reason, however, is that I can purchase whole-house allergen air filters (14X20")from Wal-Mart or Lowe's. The improvement in the quality of air within the coach and the reduction in dust is significant. As for maintenance, I've downloaded the service manual for any A/C tech to look at, and when I had a failed capacitor and circuit card I called the manufacturer (AirxCel)and had the parts shipped overnight.

[427435]

Mr.Mark wrote:


In 8.5 yrs. of motorhoming, I've never seen a roof-air shroud caught in a tree.


MM.

Low bridges have caught some. And I couldn't get mine through my 12' shed door if there was an AC on the roof.

[Skid_Row_Joe]

pump-dump-go wrote:
Howdy, been busy searching for good used ("our first class A") motorhomes, and finding a lot of good floor plans, mostly with slides.
Some Ford, some Chevy, and some diesel, and all in good shape with good prices. So I stop rambling on, here is my question.
Roof top ac, or basement h/a, pro and cons, noise levels.
Common sense tells me no units on top, lower roof clearance, less chance of roof leaks, but would like to know what others have experienced.
Thanks in advance

:h Exactly which brands and unit models of rigs are you looking at?

Mine's got roof air, and bus air - both in my big unit. I use bus-air when underway, and roof air when parked.

[Mr_Mark1]

ferndaleflyer wrote:
If you never had one or the other just comment on the one you know about....I wouldn't have a roof air unit----they look funny hanging on a low tree limb. Yes basement units as a rule have 2 compressors (mine does) My basement unit is ducted through the ceiling (won't freeze my ankles) has been serviced regular by my house a/c man without a problem and I can't hear it running. I guess mine is a heat pump because the heat is down there also but comes out of the floor ducts. I don't use the storage bays so that don't matter either......decisions!

In 8.5 yrs. of motorhoming, I've never seen a roof-air shroud caught in a tree.

I'm sure both type units work well. We were parked next to a basement unit in east Arkansas that was rather loud. The evening was nice where we wanted our windows open. The basement unit next to us was roaring. I'm sure the occupants were happy but I've never heard a roof air run that loud. Yours might be quieter.

MM.

[ferndaleflyer]

If you never had one or the other just comment on the one you know about....I wouldn't have a roof air unit----they look funny hanging on a low tree limb. Yes basement units as a rule have 2 compressors (mine does) My basement unit is ducted through the ceiling (won't freeze my ankles) has been serviced regular by my house a/c man without a problem and I can't hear it running. I guess mine is a heat pump because the heat is down there also but comes out of the floor ducts. I don't use the storage bays so that don't matter either......decisions!

[RayChez]

427435 wrote:
The basement AC that I know about have two compressors. If one goes out, the other still runs.

Very true, but one compressor alone is only good if the temperature is not over 80 degrees. The Coleman two ton BTU air conditioner/with heat pumps does have two compressors, but they automatically cycle from one to two compressors at a time in order to your required needs for cooling or heating.

[427435]

The basement AC that I know about have two compressors. If one goes out, the other still runs.

[pump-dump-go]

Howdy again, read above post, thanks for the info, both have pros and cons as I thought. Thanks for the advise about ducting which muffles noise compared to direct vents. Knew basement would take some storage space, but won't be "fulltimers", so I may can live with 25% area lose. Like the idea if one units goes out, you have another setting up there to help cool, (that's if you have 2 units and not just 1).
Thanks 🙂

[wa8yxm]

Do roof A/C's make more noise? Technically no.. but read on.
Roof air comes in two types.. Direct and Ducted.. Ducting muffles the noise so though they make a lot of noise.. you do not hear it.. Direct outlet types (Where the air goes in one side of the big grill and comes out the other) are way noiser.

Basement air is always ducted.. So its always muffeled.


Which does a better job?

Hot air rises.. Cool air sinks.. ROOF air is mounted where it's hottest so it has the best shot at cooling the ENTIRE coach

Basement air does agreat job on your ankles

Which is easier to fix? When my roof Air quite it took a few days.

First I had to go to the dealer, Select and purchase a new upper unit
Then I picked up the adapt-a-kit and read the instructions (Figgered someone should) and made an appointment.

Then I went in and in less than an hour the new one was installed and tested.

[tropical36]

pump-dump-go wrote:
Howdy, been busy searching for good used ("our first class A") motorhomes, and finding a lot of good floor plans, mostly with slides.
Some Ford, some Chevy, and some diesel, and all in good shape with good prices. So I stop rambling on, here is my question.
Roof top ac, or basement h/a, pro and cons, noise levels.
Common sense tells me no units on top, lower roof clearance, less chance of roof leaks, but would like to know what others have experienced.
Thanks in advance

Roof units cool better IMO.
Easier access for working on.
More basement space.
And above all, if you lose a roof unit in the middle of a tropical day or night, you have another one left for deciding on replacement or repairs.

[shaneperch]

I have one bus built out of stainless steel and the roof is stainless steel and I don't want to cut my roof as there are two escape hatches in it and the less penetrations like a house the better. My Flxible conversion has basement air installed from the factory and two roof air units, My other bus I will install a basement type system.

[Mr_Mark1]

mike brez wrote:

JimM68 wrote:
Our roof air's are horribly noisy, especially if I open the main vent (bypasses the ducting)
Generally at night, we'll run the front only and let the ducts feed air to the bedroom, then we don't have to hear it.

I've heard common basement a/c's used in class A's are obsolete and very hard to get parts and repairs for. Far as I know, Winniebago/Itasca was the only mainstream manufacturer to use them. (note I'm not talking buses here, just regular class A's)

I think even two million dollar Prevosts have roof air. Four or five of them.

Mike, generally, the 'bus' motorhomes will have four roof-air units, the entertainer buses will have five (and probably two generators). We have one 20 kW Kohler generator on roll-out with centrally controlled air bag suspension.

The conversion buses can have what they call 'bus air'. The air unit is in a vented side compartment with air vents at the window sills that can only be used with the main engine running. There can also be a combination of 'crusie-air's' that is really a basement type unit. I've seen our converter use two cruise-air's and two roof top air units on two or three slide coaches.

'Bus-air' can only be on a two slide or less coach. We have four slides, so 'bus-air' was not an option. Since we've never had it, I don't feel like we are missing anything. There are some bus owners that would never have a coach without 'bus-air'.

Our coach has four roof top 13,500 btu air/heat-pump units. The venting was designed from a computer program to optimize air flow and noise reduction. I have yet to use all four units at once. Two seem fine 90% of the time. The force of air that comes out of the vents is really surprising. When you walk through the salon and happen to walk under a vent, it is startling at how much air comes out compared to the air flow noise.

The four air units are low profile so you can't see them sticking up beyond the upper roof-line awnings.

MM.

[webslave]

bsinmich wrote:
When I had my Mountain Aire with 2 ducted roof ACs it was so quiet that I did not have to turn the radio up to hear it. Quality MHs have quiet roof air. Less expensive and entry units can be very noisy.

We have two roof mounted heatpumps. Very quiet and I've got all of my bays free. I don't think, nowadays, that you can generalize that one mounting system is better than the other...it really boils down to the implementation design of individual manufacturers. I much prefer having those boxes on the roof as opposed to giving up almost 25% of my basement storage. We snowbird, and my wife would have serious withdrawal issues if I told her we couldn't take her weaving look with us; in fact it could be a life and death situation...mine, not hers ??

[bsinmich]

When I had my Mountain Aire with 2 ducted roof ACs it was so quiet that I did not have to turn the radio up to hear it. Quality MHs have quiet roof air. Less expensive and entry units can be very noisy.