Updated: 2026-10-02
Concealed or exposed AC piping? Photos to send before replacement
Understand the difference between concealed and visible piping, why reuse cannot be promised from one photo, and the four photo groups that help prepare an air-conditioner replacement quote.
Short Answer
Exposed piping remains visible along a wall or inside a surface-mounted cover between the indoor and outdoor units. Concealed piping runs partly or mostly inside walls or ceilings, so the full route cannot be inspected from outside. Whether an existing line can be reused depends on the old and new models, refrigerant, pipe diameter and thickness, damage, insulation, length, contamination, and any extra hose required by the new model. Before buying, send photos of the indoor pipe exit, outdoor exit, outdoor unit, and both model labels for a model-specific installation check.
Checklist
- ・Show where piping disappears into a wall or ceiling
- ・Do not assume an existing concealed line is reusable from appearance alone
- ・Photograph the indoor side, outdoor exit, outdoor unit, and model labels
- ・Check the new model's piping and extra-hose requirements before purchase
Exposed piping is visible; concealed piping runs inside the building
With exposed installation, the route from the indoor unit to the wall opening and down the exterior wall is usually visible under wrapping or a surface cover. Concealed installation routes some or most of the line through a wall or ceiling. A cover alone does not prove the system is concealed, and a route can be partly hidden. Photograph both the indoor and outdoor sides rather than deciding from one room view.
Replacement may be possible, but line reuse is conditional
Mitsubishi Electric and Daikin publish conditions under which existing piping may be reused. Checks can include dents, bends, diameter, wall thickness, separate insulation, contamination, and the failure condition of the old compressor. JRAIA separately recommends new refrigerant piping when replacing an R22 unit with an R410A or R32 unit. Requirements vary by maker and model, so neither automatic reuse nor automatic rejection is a safe promise.
Photo one: the indoor unit and wall entry
Take a wider photo showing the complete indoor unit, the point where piping enters the wall, ceiling or access space, the outlet, and nearby furniture or rails. This helps explain both the route and working clearance. Do not climb to open a high access panel merely for a photo; state that the hidden area is not safely visible.
Photos two and three: the outdoor exit and unit route
Photograph the building area where the pipes emerge, then the complete outdoor unit and the visible route toward it. Include enough surroundings to show whether the unit is on the ground, balcony, roof, or another support. Do not enter unsafe ledges or shared restricted areas and do not remove covers or fittings yourself.
Photo four: both model labels
Take separate, readable photos of the indoor- and outdoor-unit model labels. They help identify the current refrigerant, capacity, and approved combination. Share serial numbers or label QR codes only with the service provider rather than posting them publicly. If a replacement model is being considered, include its exact model or official product page as well.
Some functions need another hose or installation route
Depending on the model, ventilation, humidification, or automatic dust discharge can require another hose in addition to refrigerant lines, wiring, and drainage. Daikin notes that some humidifying models are incompatible with embedded existing routes, while Panasonic describes mode changes or dedicated parts for some concealed installations. Check the desired features against the actual route before purchasing the unit.
Photos prepare the survey; they do not replace it
Photos cannot reveal the full pipe length, hidden bends, wall thickness, internal oil, or continuous insulation. Ask what conditions allow reuse, when cleaning or a new line is required, whether an exposed replacement route is possible, and when extra work will be quoted. The final scope should follow the actual site and the new model's installation instructions.
Discussing concealed-piping replacement in Nagoya
Our air-conditioner installation starts from ¥26,000, including tax. This is a current starting price, not a flat total that includes removal, concealed-line reuse, cleaning or replacement, extra hoses, high access, or electrical work. Send the indoor and outdoor route photos, both model labels, and the replacement model being considered. We check the site and installation criteria, then explain the required scope and total before work starts.
References
- Mitsubishi Electric: concealed piping and replacement considerations (Japanese)
- Mitsubishi Electric: conditions for reusing existing or concealed piping (Japanese)
- Daikin: concealed-piping replacement and model selection (Japanese)
- Daikin: existing piping and interconnection-wire reuse flow (Japanese PDF)
- JRAIA: installation points for R410A and R32 units (Japanese)
- Panasonic: extra-hose and mode-change examples for concealed installation (Japanese PDF)
Need help with the actual work?
Photos and a short description help us understand what work may be needed.