Filter FAQ

Filter FAQ Page

The Filter FAQ page at Irish Filters will help you find answers to common or frequently asked questions relating to filters in general but particularly air filters, DPF or FAP, water softeners and water filter systems. Designed in a Questions and Answers layout, the Filter FAQ pages will help you stay informed on many of the issues relating to the air we breathe and water we drink.

What is a DPF?

The DPF is a Diesel Particulate Filter, sometimes known in French as an FAP filter, and is a filtration technology used in most modern diesel powered vehicle exhaust systems. The DPF is designed to filter out and remove diesel particulate soot matter from the exhaust gas of the diesel engine. The purpose of the filter is to remove as much particulate matter or soot as possible from the diesel engine exhaust gas before it exits the tail pipe and allow the vehicle to meet strict vehicle exhaust emissions regulations. Variations of DPF’s or Diesel Particulate Filters have been in use in off-road machinery since about 1980, while some high-end vehicles, buses, trucks and lorries starting using them in the mid-1980s. Owners of French diesel cars such as Citroen and Peugeot may be more familiar with FAP filters (Filtre à Particules) which is French for Particulate Filters. Most Diesel Particulate Filters or DPF’s utilise a honeycomb type ceramic filter which is similar to a catalytic converter except the holes are much smaller. As the exhaust gasses flow through the honeycomb filter, the DPF captures the harmful molecular diesel particulate (soot), which is sub-micron in size. Depending on the manufacturer, the on-board engine management system will cause the DPF to activate a “Regeneration Cycle” when a certain level of soot has been captured within the DPF. When the system regenerates, it simply increases exhaust temperatures to a high enough level which then burns off the soot inside the filter, thereby safely removing it.

The DPF is an important service item in a modern diesel powered vehicle and has to be maintained properly in order to avoid very costly repair bills. Most manufacturers guarantee under warranty how long a unit will last as long as the owner drives the vehicle in normal driving conditions. Improper driving, not allowing the regeneration cycle to complete or not following the recommended procedures can cause blockages and erroneous regeneration cycles that may damage the component prematurely. A common problem which can cause soot build up in the DPF is when drivers make frequent short journeys at low speeds, or undertake journeys where the DPF cannot effectively regenerate itself. To learn more about the DPF, visit the Filtration Solutions section.

What causes hard water?

Rain falling from the clouds is naturally soft and in years past, people all over Ireland collected and used rainwater for washing clothes and even used it for washing their hair. Rainwater becomes hard if it peculates through chalk, limestone and other minerals in the ground and dissolves some of these minerals in the process. The minerals in the ground that cause hardness in water vary depending on the surrounding geology. The source of your water supply, be it a river, lake or ground water well also determines the hardness of your water. It is well known that most of Ireland has hard water. Hard water is a problem in modern homes because it forms scale (limescale) in pipework and in particular, in hot water tanks and plumbing. When hard water is used for showers, washing clothes and general cleaning it often requires excessive use of soaps, shampoos and detergents which leads to more expense. Other effects of scale (limescale) can be seen or heard in the water heating system with symptoms such as sludge, noisy radiators, reduced flow and poor efficiency. In many cases the entire heating system of a home may have to be replaced as it could become so inefficient. Other household appliances such as kettles, dishwashers, irons, showers and washing machines can be badly affected by scale leading to frequent failure and costly replacement.

What are the benefits of a water softener?

Hardness minerals or salts in water can be removed by “softening”, a low cost, reliable and well-proven technology. The water is passed through an ion-exchange bed which removes the calcium by exchanging it for sodium (which doesn’t cause scale). Water softeners generally use an ion exchange process to lower levels of calcium and magnesium (the scale that may have accumulated in plumbing and fixtures) as well as barium and certain forms of radium. They do not remove most other forms of contamination but may be used in conjunction with pre-filters and post-filtration devices to remove other contaminants. Since water softeners usually replace calcium and magnesium with sodium, treated water may have a high sodium content and for this reason some people may be advised by their doctor to avoid softened water, for example if they are on a low-sodium diet. It’s also better if babies’ milk feed is prepared with untreated water. For normal healthy people, drinking softened water is no problem and most installers include a separate filtered hard water tap fitted at the sink so people can choose for themselves. Watering lawns and plants with softened water is both costly and wasteful and not recommended. There are many benefits in using softened water. Softened water reduces scale in pipework, particularly in hot water tanks and plumbing. It also requires much less use of detergents and soaps in washing and cleaning. It also helps prevent scale from forming in your water heating system and often eliminates symptoms such as sludge and noisy radiators as well as improving flow and efficiency. Softened water will help prolong the life and efficiency of a household entire heating system. Additionally, appliances such as kettles, dishwashers, irons, washing machines and showers will last much longer. The bottom line – soft water will save money and hard water will generally cost money!

How do water softeners work?

Water softeners have been in use for many years using a technology called ion exchange which is simple, effective and reliable. In the ion exchange process, calcium ions (Ca) and magnesium ions (Mg) are exchanged for small amounts of sodium ions (Na). An ion exchange resin which comprises very small polymeric beads charged with certain ions is used to accomplish the process. Hard water is treated or softened as it flows through the resin bed created by these tiny synthetic resin beads. Calcium and magnesium ions in the hard water (which cause the lime scale we see on appliances) swap place with sodium ions as the water flows through the resin. The sodium ions unlike calcium and magnesium are highly soluble and therefore do not cause scale, limescale or scum on appliances. Over time, the sodium ions will all be exchanged for the calcium and magnesium ions and must be recharged or regenerated with fresh sodium ions. This is achieved by flushing the resin with salt solution or brine. Most water softeners employ a tank which holds and dissolves the salt for the regenerating brine and most regenerate automatically. Some water softener manufacturers use a timer to determine when to regenerate and others measure the volume of water treated to determine when to regenerate.

Why should I change the cabin air filter in my car?

An unchanged cabin air filter could cause the health of drivers and passengers to become impaired, leading to headaches, nausea and allergies. Additionally, if the cabin air filter goes unchanged, it can lead to a restricted air flow which in turn may cause decreased performance in heating and air conditioning. When the demister can’t get enough air flowing a through it a common symptom is fogging and moisture build up in the windscreen and windows.

Where is the cabin air filter in my car located?

Most passenger cars manufactured today include a cabin air filter which filters the air entering the passenger compartment through the heating/ventilation system or air conditioner. Because of the higher population density and traffic congestion, Europe and Asia are the leaders in installing cabin filters in their passenger vehicles. To find the location of the cabin filter, first check your owner’s manual. This is where you will find out first if your vehicle has a cabin air filter installed and then where it is located. If your car does not have a cabin filter or if it is not changed regularly, your car’s engine could be getting cleaner air than you!

What is an activated carbon cabin air filter?

The principle purpose of a cabin air filter is to remove and stop harmful and irritating contaminants from entering the passenger compartment. The standard particle cabin air filter also prevent leaves, dirt, bugs and other debris from entering the HVAC system and negatively impacting the operation of the heating system, air conditioner, defroster or demister. The Activated Carbon cabin air filter is an upgraded version and is impregnated with an activated carbon material to help eliminate outside odours from entering the passenger compartment. The Activated Carbon cabin filter can be easily recognised by it’s dark coloured media while the standard particle version is usually white.

What is an activated carbon water filter?

The majority of water filters sold include activated carbon in one form or another. Activated carbon, often referred to as activated charcoal is a form of carbon processed to have small, low-volume pores that increase the surface area available for adsorption. Due to its high degree of microporosity, just one gram of activated carbon has a surface area in excess of 500 m2, as determined by gas adsorption. Activated carbon is usually derived from charcoal and made by carbonising various natural materials like coal or coconut shell and then applying steam or other treatments to activate the high surface area. Most activated carbon is made in granular, powder or porous block form and supplied in a cartridge with water filters. When water passes through the activated carbon media, organic contaminants are adsorbed onto the high surface area. The media also has the effect of reducing chlorine in the water  and, as chlorine and organic contaminants are the main reason for complaints about the taste, odour and colour of household water, activated carbon filters are very popular in the treatment of drinking water. The carbon cartridge is usually contained in a housing which is connected to the water supply most commonly under the kitchen sink. The treated water from the filter is then dispensed from a separate, dedicated drinking water tap on the sink. These activated carbon filters are used as a point-of-use filters and are not usually used to treat the whole house supply.