Water and electricity safety inspection for old house renovation: Uncovering the potential risks of a 30-year-old house and the key to renovation

Walking in downtown Taipei, you can see apartment buildings that are 30 to 40 years old everywhere in the alleys. These old houses carry the life memories of many people, but the water pipes and wires buried in the walls may silently age and rust over time, becoming time bombs in life. A senior plumber in New Taipei City shared that he has dealt with the most common emergency repair cases in old houses, such as power outages without warning in the middle of the night, yellow-brown rusty water seeping out of the walls, or water pressure plummeting in the middle of a shower. These are the final alarms issued by old pipelines. Before deciding to renovate an old house, the first priority is not to discuss the style, but to conduct a thorough "water and electricity safety physical examination." As for electricity, the primary dangerous element is "aluminum wire". From the 1970s to the 1980s, many buildings in Taiwan used aluminum wires to save costs. Aluminum wires have poorer conductivity and plasticity than copper wires, and their joints are prone to oxidation and heat generation, which is the main cause of fires in many old residential wires. Checking the electrical box is the fastest way. If you see that the wires are silver-white instead of copper-colored, it is almost certain that they are aluminum wires and must be completely replaced. Next, open the main switch box of your home. If there is only a row of non-fuse switches (NFB) and you don’t see a test button on any of them (they are leakage circuit breakers), it means that the socket circuits in the whole house lack the most basic leakage protection, especially in areas with heavy moisture such as bathrooms and kitchens. The risk is extremely high. As for water, the problem is equally thorny. Old houses commonly use banned "galvanized iron pipes". The inside of such water pipes is very easy to rust. Not only is the quality of the water flowing out problematic, but the peeling of rust is also the culprit that causes water pipes to become clogged and water pressure to decrease. Tap the exposed water pipe gently. If the outer powder layer feels loose and brown rust stains can even be seen, the iron pipe is correct. What is even more troublesome is the "sewage pipe" (sewage pipe). In the early days, cast iron pipes were mostly used. Over time, scale on the inner wall will reduce the diameter of the pipe and make it easy to clog. The joints may be loosened due to earthquakes and leakage of odor. Once there is a problem with these pipelines hidden in the floor, repairing them will definitely be a major undertaking. Now that we understand the crisis, where should we start with the renovation of water and electricity in old houses? Professional masters will recommend "re-doing it all, once and for all." In terms of circuits, we must start from the main switch at the back end of Taipower's meter, replace it with a standard distribution box that meets modern electricity needs, and plan enough dedicated circuits for lighting, sockets, kitchens, bathrooms, and air conditioners (each separate air conditioner should have an independent circuit). Wires must all use CNS-certified "600V PVC insulated wires (such as 2.0mm single core wire or 3.5mm² stranded wire)" and be protected by PVC tubes or EMT tubes. Switches and sockets must be grounded, which is the most lacking safety measure in many old houses. The waterway renovation is to completely replace all galvanized iron pipes of exposed and concealed pipes with "stainless steel pressure pipes" or "CPL pipes". Stainless steel pipes are corrosion-resistant and have a long life; CPL pipes have the advantages of high temperature resistance, pressure resistance, and few joints and are not prone to leakage. Both are currently the mainstream choices. Don't forget to update the "water control valve" (the switch that turns off the water source) at the same time. Old valves often don't close tightly, so future maintenance will be easier after replacing them with new ones. When renovating a bathroom, the waterproofing project must be closely coordinated with the plumbing project. After the new pipelines are configured, a water storage test must be conducted for at least 48 hours to ensure that the floor and wall are waterproof. How to budget for such a comprehensive renovation? Take an old apartment of about 30 square meters in Taipei as an example. If all water and electricity are removed and redone, the cost may fall between NT$200,000 and NT$350,000, depending on the complexity of the pipeline and the brand of materials (such as international brands or Siemens switches). This money is spent in an invisible place, and it may not seem concrete, but in exchange for peace of mind and convenience in the next ten to twenty years, it is definitely the most core and most worthwhile investment in the renovation of old houses. After all, no matter how beautiful the decoration is, if the foundation is unsafe, everything is just a castle in the air.

New knowledge on air conditioning power consumption and Taiwan climate maintenance regulations in recent years (2025-2026 current situation)

With the high temperatures in summer breaking historical records and the adjustment of electricity price structure in recent years, the latest statistics from the Energy Administration of the Ministry of Economic Affairs show that air-conditioning equipment accounts for more than 47% of residential electricity consumption in summer. Many people mistakenly believe that if the air conditioner is not cold, they only need to "replenish the refrigerant." However, in fact, refrigerant is not naturally consumed during normal operation in a closed circuit. If the refrigerant is insufficient, it means that there are micro leaks in the copper pipes or joints. Simply replenishing the air conditioner will only treat the symptoms but not the root cause. Refrigerant leakage will aggravate the high temperature overload of the compressor and shorten its service life.

According to Taiwan's standard operating specifications for air-conditioning projects, it is recommended that professional technicians with a refrigeration and air-conditioning decoration technician license perform "full machine high-pressure water washing and evaporator deep sterilization" every 1 to 2 years for detached air-conditioning indoor units. Especially in the humid summer in the Shuangbei Basin, the air drum and water collection tray are easy to breed black mold and jelly-like biofilm. This is also the main reason for the sour smell in the air-conditioning outlet and the backflow of the drainage pipe. Regular maintenance can maintain CSPF (Air Conditioning Seasonal Performance Factor) level one energy efficiency level, which can save an average household 15% to 20% of air conditioning electricity bills every year.

Autonomous simple maintenance vs professional maintenance safety red line

• Homeowners can do by themselves: Remove and clean the nylon filter regularly every 2 to 3 weeks (rinse with clean water and dry in a cool place, do not expose it to the sun to avoid deformation and embrittlement); clean the air outlet blades of the indoor unit with a dry cloth; check whether there is any accumulation of debris within 50 cm around the outdoor unit that hinders heat dissipation.
• Professional technicians must be entrusted according to regulations: Refrigerant pressure testing and leakage repair welding, high-pressure cleaning of indoor unit air drums and aluminum fins with liquid chemicals, reset of the drainage slope of hidden cold water pipes in the ceiling, and 220V dedicated power circuit configuration and leakage circuit breaker replacement.