Breezonic Slim Power: Planning an RV Roof Before Buying AC

Start an RV air-conditioning upgrade with a roof plan and an electrical plan. The unit must fit outside and inside the vehicle, and its electrical demand must match the available supply. Selecting only by the largest cooling number can leave expensive installation problems unresolved.

The 2026 product signal

Eberspächer's 2 June 2026 Caravan Salon announcement introduced the Breezonic Slim Power with advertised cooling capacity up to 2.8 kW. The Slim family uses a compact platform and offers different output classes. This makes it a useful example of why physical packaging deserves attention alongside capacity. The announcement is not proof that a particular installation will fit your RV.

Draw three separate envelopes

The first envelope is the rooftop equipment footprint. Include nearby solar panels, roof lights, antennas and access paths. The second is the installation envelope: the opening, structural support and clearances required by the chosen manufacturer's instructions. The third is the indoor envelope, including the air distribution unit, cabinet doors and the space a standing occupant needs.

A housing can fit between two roof accessories while still lacking the required ventilation or service access. Likewise, an acceptable exterior installation may place the indoor outlet directly against a partition. Use the installation drawing for the exact version under consideration, rather than a photograph or a nominal roof-opening dimension.

Keep cooling power separate from electrical input

A 2.8 kW cooling claim describes heat removal under stated conditions. It does not mean the equipment continuously draws 2.8 kW of electricity. Obtain the rated supply, input range, starting behavior and operating limits. If an inverter or battery system is involved, assess it as part of the complete electrical installation.

At a campsite, other appliances also consume the available supply. Before buying, list the loads that will run simultaneously and ask the installer to check that combination. A reduced starting demand does not remove the need to check continuous demand and protective devices.

Make the purchase decision measurable

Ask for an annotated roof drawing, the completed installed weight, an electrical compatibility statement and a maintenance-access plan. During commissioning, check airflow where people sit and sleep, and verify that the chosen operating mode meets the agreed comfort requirement. Preserve the drawings with the vehicle records so that a future solar or antenna upgrade does not compromise the AC installation.

How do you inspect an RV roof layer by layer before marking a cutout?

A rooftop unit never mounts on a drawing; it mounts on a structure made of outer skin, insulation, framing and a finished interior surface. Before any position is marked for a slim platform such as the Breezonic Slim Power, walk the roof in layers: skin condition, available framing, the route between structure and interior, and the underside where the air distribution unit will hang.

Inspect the outer skin for previous repairs, delamination and load-bearing areas that may not match the original layout drawings. A motorhome that has been re-roofed or patched may have framing where the brochure shows none, and the opposite is just as common. Photograph each layer as evidence for the installer's quotation and for your own files.

Finish with the structural question: where will the load actually rest? A slim housing spreads load differently from a tall unit, but both need support at the opening and around every fastener. Confirm the permitted roof load with the vehicle manufacturer before any equipment is added, and record that answer next to the survey photographs.

Write the survey findings on a single sheet: layer, condition, action required. That sheet travels to the installer together with the tape measurements, so the quotation covers the roof you actually have rather than the roof in the brochure.

Outer skin condition, including previous repairs and soft spots
Framing positions confirmed from below where possible
Roof thickness at the proposed opening
Existing solar panels, roof lights, antennas and their cables
Drainage path and standing water after rain
Underside obstructions such as cabinets, ducts and wiring
Access for lifting the unit onto the roof
Photographs of every layer, numbered and dated
The permitted roof load as confirmed by the manufacturer
Roof thickness and framing measured, not assumed
Condition of any existing penetration and its seal
The person who performed the survey and the date
Any area the manufacturer excludes from roof equipment
The cable route from the unit to the power source
The expected weight of the finished installation
The age of the roof and any previous water ingress
Whether the manufacturer requires documentation of the added load

Where should the indoor unit sit so furniture and walkways survive?

The indoor position decides daily usability more than the rooftop position does. Mark the proposed ceiling location with masking tape inside the vehicle, then live with it for a day: open every cabinet, make the bed, walk the aisle and sit at the dinette with the outline overhead. Most conflicts are obvious within minutes once the outline exists at full size.

Check the three conflicts that appear most often in compact motorhomes: cabinet doors that no longer open fully, bed platforms that collide with the outlet, and standing headroom on the main walkway. Each conflict found on tape costs nothing; each conflict found after the cutout costs a roof, a ceiling lining and a rescheduled handover.

Record the chosen position with measurements from two fixed reference points, never as a description such as next to the roof light. Installers work from numbers, and a position written this way survives a change of workshop between quotation and fitting, or a return visit months later.

Involve the person who builds or owns the furniture before the position is final. A cabinet maker can move a shelf, but only before the panels are assembled; afterwards the same change means a new front, new hinges and a repainted ceiling. A fifteen-minute conversation at the tape stage is the cheapest adjustment available in the whole project.

Tape the full outline, including trim and adapter
Open every cabinet and drawer through its full swing
Test standing and seated headroom at the walkway and dinette
Check the bed platform and the path to the entrance
Confirm the service panels stay reachable
Measure from two fixed reference points and write them down
Ask the furniture builder to confirm the position before cutting
Photograph the tape outline with the measurements visible
Confirm the trim and adapter are inside the outline
Leave a note in the vehicle file naming the chosen position
Confirm the outline does not overlap a roof hatch escape route
Check that the position leaves room for the ceiling trim
Agree with the builder who installs the final trim piece
Bring a tape measure, a straight edge, masking tape and a marker
Use a plumb line or laser where the ceiling must align with the opening
Mark both sides of the assembly, not only its middle

How should the electrical plan be tested against real camping scenarios?

The earlier section separates cooling output from electrical input; the next step is scenario testing. A campsite hookup on a hot weekend, a night on battery after a cloudy day, and a small supply line at a mountain site produce three different answers about whether the installation is complete. Test the plan against each of them before the unit is ordered.

For every scenario, list the loads that run together: the air conditioner in its expected mode, the fridge, chargers and anything that heats. Compare that total with the supply available in the same scenario, including any power limiter at the pitch. A reduced starting demand still requires continuous power for hours, and campsite supplies are often shared.

Start the scenario work with a plain load inventory, because most electrical surprises come from appliances that were never written down. Walk the vehicle with a notepad and switch on everything a real trip uses, then note the rating printed on each device. Guessing produces a plan that works in the driveway and fails at the campsite.

Charging can wait until the generator hour or the drive to the next site
The air conditioner cannot wait, so it sets the supply requirement
A written priority order turns a tripped breaker into a decision already made
Keep the order with the vehicle documents for later trips

Scenario	Main question	Evidence to collect
Campsite hookup	Does the site supply carry all simultaneous loads?	Supply rating, breaker size, pitch limiter setting
Battery night	What remains in the battery by morning?	Measured input over the night, protection settings
Small supply	What must be switched off to run the AC?	Load list, priority order, protection behavior

Ask the installer to document which protective devices make each scenario safe: the supply breaker, the vehicle's internal circuits and any battery protection settings. Keep the completed table with the vehicle documents, because it is the first thing a future fault investigation will ask for.

Air conditioner in each mode the owner expects to use
Fridge, including its starting surge
Phone, laptop and camera chargers
Water pump and lighting in the evening
Any inverter losses between battery and appliance
Cooking or heating appliances that share the supply
Roof fan or extractor running alongside the AC
The chargers left plugged in overnight
The roof fan used at the same time as the air conditioner
A second fridge or freezer added for longer trips
Any appliance the owner plans to add next season

How do you fit rooftop equipment into payload and weight distribution?

Roof equipment is payload. Before ordering, weigh or estimate every addition connected to the project: the rooftop unit, the indoor assembly, reinforcement, cabling and any extra battery added to support longer running. Compare the total with the remaining payload after water, fuel and the luggage a normal trip carries.

Distribution matters as much as the total. A heavy roof load ahead of the front axle changes handling and can push the vehicle past a front axle rating long before the overall payload is reached. Ask where the manufacturer permits roof-mounted equipment, and record the axle loads after the installation rather than assuming they stayed the same.

Re-weigh the vehicle once the work is complete, with the tanks in travel condition. Keep the weighbridge ticket in the vehicle file: it documents the legal baseline for every future accessory decision, from a second solar panel to a roof box, and it answers questions at resale.

Remember that weight also moves when equipment is removed. A previous rooftop unit taken off the roof, an old battery bank replaced by a smaller one, or a bike rack sold on all change the same numbers, and the paperwork should be updated at the same time. A payload note that lags behind the actual vehicle is worse than none, because it creates false confidence in a legal margin that no longer exists.

List every item added by the project, including fixings and cables
Estimate each weight and add a margin for sealing and trim
Compare the total with the remaining payload
Check the permitted roof load and axle ratings
Weigh the finished vehicle in travel condition
File the ticket and update the payload note for the owner
Repeat the weighing after any later roof or battery change
Note the weighing date and location on the ticket
Review the payload margin before each accessory purchase
Compare the axle load note before and after the project
Keep receipts with the declared weights for later checks

In what order should the installation run so the roof is opened once?

The cheapest installation is the one performed in the right order, because a roof opened twice costs double in sealing risk and workshop time. Sequence the work so that structure, penetration, wiring and interior finishing are each complete before the next stage begins, and hold a check at every boundary between trades.

Confirm the position with the tape outline and the written measurements
Reinforce the framing and prepare the support surface before any cut
Cut the opening and dry-fit the mounting frame before sealing
Route and test the electrical connection while the interior is still open
Fit the rooftop unit, seal it and allow the stated curing time
Hang the indoor assembly and check clearances against the drawing
Run the commissioning checks recorded in the planning documents
Photograph the sealed roof and the finished ceiling
Update the vehicle file with drawings and part numbers
Walk the owner through the operating and maintenance points

Hold points make the sequence enforceable. Reinforcement must be inspectable before the opening is cut, wiring must be tested before the ceiling closes, and the seal must cure before the roof carries any load. Rushing these boundaries is the most common cause of return visits after a retrofit.

If the workshop proposes a different order for a good reason, write the reason down and the person responsible for it. An agreed deviation is part of the plan; an unspoken one becomes a surprise discovered at handover, usually on the first rainy night of a trip.

Weather belongs in the sequence as well. Sealing compounds behave differently in cold or damp conditions, and a roof that is wet cannot be prepared properly. Build a weather window into the schedule rather than letting a delivery date force the sealant work into conditions it was never specified for, and keep the vehicle under cover until the stated curing time has passed.

Reinforcement visible and photographed before the cut
Wiring continuity tested before the ceiling closes
Seal cured before the roof is loaded or driven
Clearances checked against the drawing after the indoor unit hangs
Electrical scenario table completed and signed before handover
Owner shown where the filters and drains are reached

Which planning mistakes are typical for slim rooftop platforms?

A slim platform solves a height problem, not a planning problem. The reduced profile tempts buyers to skip the envelope work, and the same mistakes recur across conversions: ignoring the solar panel already on the roof, assuming the existing opening will fit, and treating the electrical supply as unlimited because the unit looks efficient.

Skipping the roof survey. Measure the framing and skin rather than trusting a brochure drawing.
Reusing an old opening. A previous unit's cutout rarely matches the new installation drawing.
Underestimating simultaneous loads. Run the scenario table before ordering equipment.
Forgetting the indoor assembly. Cabinets and bed platforms are part of the fit.
Planning without documents. Use the drawing for the exact output class under consideration.
Ignoring service access. A low profile can still hide filters and drains behind trim.
Forgetting lifting and transport. Decide how the unit reaches the roof before the delivery day.
Leaving the old opening undocumented. Photograph and record any reused or closed penetration.
Ordering before the survey. Sequence the purchase after the measurements, not before them.
Skipping the weighbridge. Record the finished weight while the project is still open.

The corrective action for all six is the same: complete the three envelopes from the earlier section before any purchase, and keep the drawings with the vehicle. Ten minutes with a tape measure and the installation drawing prevents the majority of retrofit disappointments, and it makes the installer's quotation comparable with the next one.

Publish the completed plan to everyone who works on the vehicle afterwards, including the furniture builder and the electrician. Most conflicts in compact conversions are created by the last trade on site, not the first, because each one optimizes its own task without seeing the finished result.

Close the project with a review against the original plan rather than against a good impression. Walk the three envelopes one more time with the drawings in hand: does the roof match the footprint plan, does the indoor unit match the ceiling plan, does the measured consumption match the electrical plan? Three checkmarks on one page are the cheapest possible acceptance record for an RV conversion, and they take less time than most owners spend deciding where to park.

The roof survey sheet with photographs
The ceiling position measurements from two reference points
The completed electrical scenario table
The weighbridge ticket after completion
The installation order and curing dates for sealant work
The name of the installer and the date of the handover
The contact for the next service visit
A note on any deviation agreed with the workshop
One master drawing carrying all three envelopes, kept current and dated
The name of the person who owns updates to that drawing
The service contact for the installed equipment
The date of the next inspection of the roof seal

Next step

Compare the available configurations in the Vethy product catalog, then request the current model-specific documentation before selecting a unit.

Sources and method

Eberspächer — Caravan Salon 2026: More comfort in a motorhome · 2026-06-02

Frequently asked questions

How much roof space does a slim unit such as the Breezonic Slim Power need?

The announcement introduces a compact platform with different output classes, but the required space depends on the installation drawing of the exact version: footprint, clearances, ventilation and service access. Measure your roof with nearby solar panels, roof lights and antennas included, then compare against the drawing for the specific output class under consideration. Never plan from a photograph or a nominal roof-opening dimension.

Does a 2.8 kW cooling rating mean the unit draws 2.8 kW of electricity?

No. The 2.8 kW figure from the 2 June 2026 announcement describes heat removal under stated conditions, not electrical input. Request the rated supply, the input range and the starting behavior for the version being quoted, then check the continuous draw against the loads that run simultaneously at your typical campsite and the protective devices installed in the vehicle.

Can a Breezonic Slim Power be planned onto any motorhome roof?

Any roof can be assessed, but not every roof accepts the same equipment. The structure must carry the load at the opening and around every fastener, the opening must suit the installation drawing, and the interior must accept the air distribution unit with acceptable headroom and cabinet clearance. Follow the layer-by-layer roof inspection and the three-envelope planning approach in this article before committing.

When is a compact platform the better choice over a full-height unit?

Compact platforms earn their place where height is the binding constraint: low garages, pop-top conversions, vehicles with roof rails or solar arrays, and owners who prioritize handling and fuel use. The trade-off is planning discipline, because a low profile does not reduce the need for structural support, clearances and service access. Decide after the roof survey, not from the product photo.