In many residences in Taipei and New Taipei, especially those in buildings or old apartments that are more than 15 years old, homeowners often face an annoying problem: even though the toilets at home are cleaned very clean every day, there is always a faint smell of swamp and excrement. Even late at night or before the weather changes, you can still smell a strong smell of second-hand smoke and neighbors' cooking oil smoke. Many people try to put in fragrances and spray perfume, but they often just let the fragrance mix with the odor, making it even more unpleasant. In fact, this "structural odor" cannot be solved by cleaning or spraying perfume. This usually involves two basic physical concepts of water and electricity: "trap failure" and "unsealed public pipes." This article will give you an in-depth introduction to the principles of deodorization and provide modification strategies to completely solve the odor.
Core science: The first line of defense against odors - traps and water seals
Under the sink, inside the toilet and under the floor drain hole in our homes, there is a curved pipe (usually S-shaped or P-shaped) designed deep in the invisible pipes. This is the "trap".
When water flows through the trap, due to the principles of gravity and siphonage, a portion of water will automatically remain in the curved pipe. This section of accumulated water is called the "Water Seal." The height of the water seal is usually designed between 5 and 10 centimeters. This area of stagnant water may seem inconspicuous, but it is a physical barrier that prevents methane, odor, cockroaches and mosquitoes from entering the room in public sewers or building drainage pipes. As long as there is water seal, the gas in the pipe cannot float through the water into the house.
Why does it still stink even though there is a trap? Two major reasons for water seal failure
Many times, the drain trap at home still exists, but it has lost its anti-odor function, which is mainly caused by the following two major reasons:
1. The water seal dries up (not used for a long time): If your home has a guest bathroom, or you have traveled abroad for many days, and the drain hole has not been used for several weeks, the water in the drain drain will be lost due to air evaporation and dry up. Once the water seal disappears and the passage is wide open, the odor between the pipes will flow into the room endlessly. : Just pour about one liter of water into all drains regularly (once a week) to re-establish the water seal.
2. Seal breakage phenomenon (siphon and positive pressure effect): When residents upstairs in the same building drain a large amount of water, huge air pressure fluctuations will occur inside the public pipelines. If the ventilation pipe (Vent Pipe) originally built in the building is blocked, the negative pressure generated by the drainage will act like an air extractor, sucking away the water in your home's trap; or the positive pressure generated will "blow" the odor of the sewer directly through your home's water seal. This is why some homeowners hear a gurgling sound from their drain holes, followed by a foul odor.
The second source of nightmares: Unsealed panels in public ducts and backflow of exhaust fans
If what you smell in the bathroom is your neighbor's "second-hand smoke" or "perfume smell", then the problem is usually not the drain hole, but the inside of the bathroom ceiling. The building's drainage branch pipes and bathroom exhaust ducts are usually connected to a "pipe shaft" that runs vertically through the entire building. In many old buildings, there are two major construction loopholes in public pipe rooms:
1. The pipe room and ceiling are not sealed:When they were first built, there were usually large gaps in the cement walls between the pipes above the ceiling, or even no sealing at all. Neighbors' smoke and exhaust fumes can drift out from between public ducts, into the mezzanine of your home's ceiling, and into the bathroom through maintenance holes or gaps in light fixtures.
2. The exhaust fan does not have a "check valve": Most of the exhaust fans in old bathrooms are just a simple fan without a design to prevent backflow. When you turn off the exhaust fan, due to the air pressure in the common duct room, the exhaust gas will be blown directly back to your bathroom along the air duct.
Four major modification strategies and market trends in Taipei to completely eliminate toilet odors
To completely bid farewell to odors in your home, you can carry out systematic modifications through the following four steps. The reasonable market conditions in Taipei are as follows:
Strategy 1: Replace the "anti-odor floor drain" (anti-odor drain head). Replace traditional drainage gratings with odor-resistant floor drains. This type of floor drain has a one-way valve (such as a gravity flap, spring-type or silicone nozzle) inside. When there is no water, the one-way valve will be tightly closed to block odors and insects; when there is water flowing down, the valve will open by gravity. The cost of stripping materials together is about NT$ 1,200 to NT$ 2,500 per piece (depending on whether the old tiles need to be removed and re-buried).
Strategy 2: Install the "anti-odor wash basin S-tube". The hose under the sink often creates gaps because it is randomly inserted into the floor drain during installation. It is recommended to replace it with an anti-odor metal P pipe or a drainage kit equipped with a sealing rubber ring. The cost of complete work and materials is about NT$ 800 to NT$ 1,500.
Strategy 3: Replace the "back pressure check valve exhaust fan (heater)". Choose an extractor fan equipped with a physical backstop damper. When the exhaust fan is turned off, the check valve will automatically close tightly to prevent the reverse flow of odor between the pipes. It is recommended to use major Japanese manufacturers (such as Panasonic, Mitsubishi) or well-known brands from Taiwan (such as Alaska). Replacing a simple check valve exhaust fan costs about NT$ 2,500 to NT$ 4,500; if you upgrade to a heating and cooling fan, the cost is about NT$ 8,000 to NT$ 15,000 (including wiring).
Strategy 4: Pipe sealing and sealing project (once and for all). Dismantle the bathroom ceiling, fix the junction between the bathroom exhaust pipe and the public pipes with a stainless steel ring, and use fireproof foaming agent and cement mortar to completely seal the holes and gaps around the public pipes to block air flow exchange above the ceiling. Depending on the on-site ceiling structure and construction difficulty, the cost is approximately NT$ 6,000 to NT$ 15,000.
The Ministry of Economic Affairs' latest "Regulations on Consumer Electrical Equipment Installation" and the key points of electricity safety in old houses
Due to the popularity of high-power household appliances (such as air fryers, microwave ovens, dishwashers, instantaneous electric water heaters, and IH furnaces) in recent years, the Energy Administration of the Ministry of Economic Affairs has revised the "Regulations on Consumer Electrical Equipment Installation" many times to strictly require the diversion and protection mechanisms of residential electricity circuits. Statistics show that more than 30% of building fires in Taiwan are caused by electrical factors, among which "old wire insulation deteriorates and short circuits", "socket contacts are oxidized and loose, poor contact" and "non-fuse switch (NFB) overloaded and failed to trip" are the three main fatal causes.
Old apartments in Shuangbei that are more than 30 years old have a total original designed power capacity of only 30A to 40A, and several rooms often share the same 1.6mm or 2.0mm circuit. In the modern standard safety configuration, kitchen electrical cabinets, bathroom equipment, and air-conditioning and heating machines must all be equipped with 5.5mm² dedicated circuits (single circuit and single socket). It is recommended that the main switch box be upgraded to a busbar (Busbar) integrated distribution board, and the total amperage is increased to 75A or 100A (a qualified electrical appliance contractor needs to be entrusted to Taipower to review the additional power capacity).
Residential electricity self-test and regular inspection checklist
- Appearance and temperature of the socket: Touch the outer cover of the commonly used socket lightly with the back of your hand. If it feels lukewarm or if you find that the plastic socket is yellowed and charred, or the plug is loose and shaking after being plugged in, it means that the internal copper plate clamping force is exhausted or the contact resistance is too high, and you should immediately cut off the power and replace it.
- Regular testing of leakage circuit breakers (ELCB): For leakage circuit breakers in humid places such as balconies, bathrooms, and kitchen sinks, regulations require that the "TEST button" on the switch be pressed once every 1 to 3 months to confirm that it can automatically trip and cut off the power supply instantly.
- Serial connection and overloading of extension cords are strictly prohibited: Extension cords should be purchased with 2.0mm thick wire diameter products that have CNS certification and automatic overload power-off protection. Do not share the same extension cord with high energy-consuming appliances to ensure zero hidden danger to life and property at home.
