Installing an AC unit in your enclosed trailer is a worthwhile investment for comfort and functionality, especially for those using the trailer for work, recreation, or mobile businesses. Selecting the right unit, preparing the trailer, and carefully executing the installation are crucial for a successful and lasting result, transforming your trailer into a climate-controlled haven.
Understanding Your AC Options and Trailer Suitability
Before grabbing your toolbox, let’s assess your needs and the capabilities of your trailer. There are two primary types of AC units suitable for enclosed trailers: rooftop units and window units (or through-the-wall units). Each has its pros and cons.
Rooftop AC Units: A Powerful Solution
Rooftop units, common on RVs, offer significant cooling power and are designed to withstand the rigors of travel. They typically range from 13,500 to 15,000 BTU (British Thermal Units), making them suitable for larger trailers or those requiring robust cooling.
- Pros: High cooling capacity, integrated design (often including heating capabilities), aesthetic appeal (doesn’t obstruct windows).
- Cons: Requires significant roof modification, higher initial cost, potentially more complex installation involving electrical wiring and roof sealing.
Window/Through-the-Wall AC Units: Simplicity and Affordability
Window units are generally more affordable and easier to install. Through-the-wall models offer a cleaner aesthetic compared to window units hanging externally. However, they often have lower BTU ratings (typically 5,000-12,000 BTU), making them better suited for smaller trailers.
- Pros: Lower cost, relatively easy installation, readily available, minimal electrical modifications in some cases (can use a standard outlet).
- Cons: Lower cooling capacity, obstructs windows or requires a dedicated wall opening, can be less aesthetically pleasing than rooftop units.
Assessing Your Trailer
Consider the following before choosing an AC unit:
- Trailer Size: This dictates the required BTU rating. Generally, 5,000 BTU can cool up to 150 square feet.
- Power Supply: Determine if your trailer has a dedicated 30-amp or 50-amp service, or if you’ll be relying on a generator. This will dictate the type of AC unit you can power. Rooftop units typically require more amperage.
- Roof Structure: Inspect your trailer’s roof. Is it strong enough to support the weight of a rooftop unit? Reinforcement may be necessary.
- Wall Construction: For window/through-the-wall units, ensure the wall is sturdy enough to accommodate the unit and that you can safely cut an opening if necessary.
- Insulation: Proper insulation is crucial for maximizing the effectiveness of your AC unit. Adding insulation will significantly improve cooling efficiency and reduce energy consumption.
Installation Steps: A Detailed Guide
The installation process varies depending on the chosen AC unit type. The following provides a general overview:
Installing a Rooftop AC Unit
- Prepare the Roof: Locate the center of the trailer roof and mark the area where the AC unit will be installed. Ensure this area is free of obstructions like vents or skylights. Cut an opening according to the AC unit’s template.
- Reinforce the Opening: The roof opening requires significant reinforcement to support the weight of the AC unit. Use lumber to create a sturdy frame around the opening. Securely fasten the frame to the existing roof structure.
- Install the Gasket and Unit: Apply a generous amount of sealant (such as butyl tape) around the frame opening. Carefully lift the AC unit onto the roof and position it over the opening, ensuring the gasket makes a tight seal.
- Secure the Unit: From inside the trailer, attach the AC unit to the roof frame using the provided mounting hardware. Tighten the bolts evenly to avoid warping the unit or damaging the roof.
- Electrical Wiring: Connect the AC unit to the trailer’s electrical system according to the manufacturer’s instructions. This often involves running wires to a breaker box. Always disconnect the power supply before working with electrical wiring. If you are uncomfortable with electrical work, hire a qualified electrician.
- Seal and Test: Apply sealant around the edges of the AC unit to prevent water leaks. Test the AC unit to ensure it is functioning correctly.
Installing a Window/Through-the-Wall AC Unit
- Choose a Location: Select a location for the AC unit that provides adequate airflow and is easily accessible. Consider the placement of windows and doors.
- Cut the Opening (if necessary): For through-the-wall units, carefully cut an opening in the wall according to the AC unit’s template. Use appropriate safety gear, like safety glasses and a dust mask.
- Build a Support Frame: Construct a sturdy frame around the opening to support the weight of the AC unit. Use lumber and screws to create a secure and level platform.
- Install the Unit: Slide the AC unit into the opening, ensuring it is level and flush with the wall. Secure the unit to the frame using screws or bolts.
- Seal the Gaps: Use caulk or weather stripping to seal any gaps around the AC unit to prevent air leaks and water intrusion.
- Electrical Connection: Plug the AC unit into a standard electrical outlet (if applicable) or connect it to the trailer’s electrical system.
- Test the Unit: Turn on the AC unit and check for proper operation. Ensure the air is blowing cold and that there are no leaks.
Safety Precautions
- Disconnect Power: Always disconnect the trailer’s power supply before starting any electrical work.
- Wear Safety Gear: Wear safety glasses, gloves, and a dust mask during installation.
- Follow Manufacturer Instructions: Carefully read and follow the manufacturer’s instructions for both the AC unit and any tools used.
- Get Professional Help: If you are uncomfortable with any aspect of the installation, consult a qualified technician.
- Check for Leaks: After installation, thoroughly check for water leaks around the AC unit.
Frequently Asked Questions (FAQs)
1. What size AC unit do I need for my enclosed trailer?
The required BTU rating depends on the trailer’s size and insulation. A general rule of thumb is 20 BTU per square foot. However, poorly insulated trailers may require higher BTU ratings. Calculate the square footage of your trailer (length x width) and multiply by 20 to get an approximate BTU requirement.
2. Can I run an AC unit off a generator?
Yes, but you need to ensure the generator has sufficient wattage to handle the AC unit’s starting and running wattage requirements. Check the AC unit’s specifications and choose a generator that provides ample power.
3. Do I need to reinforce the roof of my trailer before installing a rooftop AC unit?
In most cases, yes. Trailers are not typically built to withstand the weight of a rooftop AC unit. Reinforcement is crucial to prevent roof damage and ensure a secure installation.
4. How do I seal the roof after cutting the opening for a rooftop AC unit?
Use a combination of butyl tape and self-leveling sealant. Butyl tape provides a watertight seal between the AC unit and the roof, while self-leveling sealant fills any gaps and creates a smooth, weatherproof finish.
5. What type of electrical wiring do I need for a rooftop AC unit?
Rooftop AC units typically require a dedicated 30-amp or 50-amp circuit. Consult the manufacturer’s specifications for the exact wiring requirements. You may need to upgrade your trailer’s electrical system.
6. Can I install a window AC unit without cutting a hole in the wall?
Yes, you can install it directly in a window opening, similar to how you would in a house. However, this will block the window and potentially require modifications to the window frame.
7. How do I prevent water leaks around a window AC unit?
Use caulk or weather stripping to seal any gaps between the AC unit and the window frame. Ensure the AC unit is tilted slightly downwards to allow condensation to drain properly.
8. Is it possible to install a mini-split AC unit in an enclosed trailer?
Yes, mini-split AC units are an option, particularly if you want more efficient cooling and heating. However, they require professional installation due to the complexities of refrigerant lines and electrical connections.
9. How much does it cost to install an AC unit in an enclosed trailer?
The cost varies depending on the type of AC unit, the complexity of the installation, and whether you hire a professional. Rooftop units typically cost more to install than window units. Expect to pay anywhere from $500 to $2000+ for the entire project.
10. What is the best way to insulate my enclosed trailer for AC?
Use rigid foam insulation panels for the walls, roof, and floor. Seal all gaps and seams with spray foam or foil tape. Consider adding reflective insulation to the roof to reduce heat gain from the sun.
11. How often should I clean the AC unit’s filter?
Clean the filter at least once a month, or more often if you use the AC unit frequently. A dirty filter reduces airflow and cooling efficiency.
12. What tools will I need for the installation?
The specific tools required will depend on the type of AC unit you are installing, but generally, you will need: drill, saw (for cutting the opening), measuring tape, level, screwdriver, wrench, wire stripper, wire connectors, sealant, caulk gun, and safety glasses.
By carefully planning and executing the installation, you can transform your enclosed trailer into a comfortable and functional space, regardless of the outside temperature. Remember to prioritize safety and consult with professionals when needed.