Choice of Water Heater: A Required Course for Old House Renovation and Plumbing
When renovating old apartments or renovating rental suites in the greater Taipei area, many homeowners will face the planning decision of the water heater system. The back balconies of old apartments often have poor ventilation. If a traditional gas water heater is installed, it is very easy to cause fatal danger because carbon monoxide cannot be discharged smoothly. In addition, the water pressure on many high floors in the greater Taipei area is low, and gas water heaters often fail to ignite smoothly due to insufficient water volume. Therefore, "electric water heaters" that are safe, do not require gas pipelines, and have less water pressure restrictions have become the first choice during renovation. However, electric water heaters on the market are mainly divided into two camps: "instantaneous type" and "thermal storage type". Not only do the two have huge physical differences in volume and water output, but the requirements for "safety of water and electricity wiring" are even different.
Instantaneous electric water heater: compact and space-saving, but with huge circuit load
The principle of the tankless electric water heater is to directly conduct heat exchange when the cold water flows through the internal high-power electric heating tube. It is hot immediately after it is turned on, without waiting.
1. Size advantage: Its size is usually only the size of a lunch box and can be installed directly above the faucet in the bathroom. It is extremely space-saving and very suitable for small suites where space is at a premium.
2. Power consumption shortcoming (fatal wiring requirements): In order to heat cold water in a few seconds, the instantaneous heating type has extremely high power (usually 9.9 kW to 10.1 kW in Taiwan). The operating voltage is 220V and the instantaneous current is up to 45A. Such a huge current requires extremely strict wiring specifications:
1. It is mandatory to use at least specifications. It is absolutely forbidden to use 2.0mm, 5.5mm² or even 8.0mm² wires from general sockets, otherwise the wires will heat up and melt within a few minutes, causing serious wire fires.
2. A dedicated and dedicated leakage protector must be installed in the electrical box.
3. The total power box capacity of Taipower in old apartments in Taipei is often only 30A or 50A. If a 45A instantaneous water heater is forcibly installed, it means that as long as someone turns on the microwave oven or hair dryer while taking a bath, the main meter switch will immediately overload and trip. Therefore, before installation, it is often necessary to entrust a plumber to apply for a "total power capacity increase" from Taipower.
Thermal storage electric water heater: The water output is stable, but it takes up space and consumes insulation electricity
The principle of the storage water heater (Storage Water Heater) is very much like a huge thermos. It first heats the water in a large bucket (such as 20 gallons, 30 gallons or 50 gallons) to the set temperature, and then directly uses the water in the thermos bucket when taking a shower.
1. Excellent water output stability: Its water output completely depends on the size of the bucket. When taking a bath, hot and cold water are mixed stably, the water temperature will never be hot or cold, and the water pressure requirements are extremely low.
2. Volume and thermal insulation energy consumption defects:The thermal storage type is huge and usually needs to be hung on the ceiling of the back balcony or hidden in the ceiling of the toilet. During construction, it is necessary to consider whether the wall can bear the weight of hundreds of kilograms of water buckets. In addition, due to the need for continuous heat preservation, even if no one is taking a shower, the host will repeatedly start heating and heat preservation, and the long-term power consumption is higher than the instant heating type that can be turned on and off at any time.
3. Electricity demand is relatively friendly to the people: The power of thermal storage is usually between 4 kW and 6 kW, and the operating current is about 18A to 27A. The water and electricity configuration only needs to be matched, which puts much less pressure on the main electrical box of the old house.
Two-Beijing market for electric water heater installation and large wire pull-outs
In Taipei and New Taipei, the construction budget for replacing or adding an electric water heater is as follows:
1. Storage electric water heater installation cost:
- About NT$ 12,000 to NT$ 18,000.
- Approximately NT$ 4,500 to NT$ 8,000 (depending on cable distance).
2. Installation cost of instant electric water heater:
- Approximately NT$ 4,000 to NT$ 8,000.
- Due to the extremely thick 14mm² wire, it is extremely difficult to thread it in the pipelines of old houses. Plumbers usually need to install metal EMT pipes or PVC plastic pipes to open pipes to the bathroom. The price of wire pulling wages and material costs is approximately between NT$ 6,000 and NT$ 13,000 (depending on the length of the pipe and the number of holes in the wall).
ROI investment thinking of commercial acquisitions and leasing companies: How to reasonably configure water and heat equipment?
For renters who own multiple sublet apartments, or businessmen who are purchasing and renovating old apartments,:
In suite renovation, although the instantaneous water heater hardware is cheap and saves space, due to its current limit of up to 45A, if there are tenants taking baths in 4 suites at the same time, the total power distribution capacity will completely collapse. In addition, the inlet water temperature in northern Taiwan is often lower than 15°C in winter, and the instant heating type often causes tenant complaints because the outlet water is not hot enough. Therefore, the best practice for commercial decoration is each room is independently configured and the power is only 4 kW (5.5mm² wiring), which can ensure comfortable bathing water temperature and no power outages, significantly reduce subsequent property maintenance complaints, and increase the long-term return on asset holding value.
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.
