PIV Units

What is a PIV Unit?

PIV stands for Positive Input Ventilation. They are designed as a very practical solution to mould and condensation problems in homes.

How Does a PIV Unit Work?

The most popular models mount in the loft and intake fresh air through filters and then push that filtered fresh air into the dwelling usually via a small ceiling grille in the hallway. The stale moist air is pushed out of the house by the pressure of the new dry fresh air. This is a continuous process so that the air in the home is always fresh and dry, preventing condensation/mould formation.

Will PIV Stop Condensation?

Positive Input Ventilation (PIV) systems can be effective in reducing condensation in a property. PIV works by introducing fresh, filtered air into the property, which displaces the moist and stale air that can lead to condensation.

The improved air circulation that PIV provides can help to prevent moisture from building up on surfaces and reduce the risk of dampness and mould growth. This can be especially important in areas such as bathrooms, kitchens, and bedrooms, where moisture levels can be high.

However, it's important to note that PIV alone may not be sufficient to completely eliminate condensation problems in a property. Other factors, such as insulation, heating, and ventilation, may also need to be addressed to fully resolve condensation issues.

In addition, it's important to ensure that the PIV system is installed correctly and is appropriate for the size and layout of the property. Consulting with a qualified professional can help to ensure that the PIV system is the right solution for your condensation problems and that it is installed and used correctly for maximum effectiveness.

Do PIV Units Work?

PIV units certainly work and are probably the most effective solution for reducing/curing mould issues in a home. They must be located and set up appropriately of course, but this is not by any means a difficult task.

Do PIV Units Run All The Time?

Positive Input Ventilation (PIV) units can be designed to run continuously or intermittently, depending on the specific model and the needs of the property.

Some PIV units are designed to run continuously, providing a constant supply of fresh air to the property. These units typically have low-wattage fans that are designed to run continuously without consuming too much energy. Continuous operation can help to maintain a consistent level of indoor air quality and reduce the risk of moisture buildup and condensation.

Other PIV units are designed to run intermittently, turning on and off at regular intervals throughout the day. These units may be controlled by a timer or a humidity sensor, which activates the unit when moisture levels rise above a certain threshold. The intermittent operation can be more energy-efficient than continuous operation, as the unit only runs when it is needed.

The choice between continuous or intermittent operation will depend on the specific needs of the property, as well as the preferences of the occupants. It's important to consult with a qualified professional to determine the best type of PIV unit for your property and to ensure that it is installed and used correctly for maximum effectiveness.

How Long Does a PIV Unit Take to Work?

In just a few weeks, a dwelling should see its mould and condensation problems disappear. Some clients report seeing effective results in just a few days. 

Do PIV Units Make the House Cold?

Generally, the air is drawn from the loft/attic, so when that air is cooler than the air in the rest of your home, it could in theory lower the overall air temperature in some dwellings. The most popular PIV units come with a pre-heater that fits on top of the ceiling grille and pre-heats the air as it enters the main dwelling. These heaters operate in a 'bypass' mode during the warmer months to avoid adding warm air when it's not desirable to do so.

PIV Installation Costs

Installing a PIV unit is a simple and quick task, with the biggest job being cutting the ceiling grille hole. It is also advisable to get a qualified electrician to connect the unit to the mains. This means that the PIV installation costs are much lower than many other ventilation solutions.

Are PIV Systems Noisy?

Positive Input Ventilation (PIV) systems can produce some noise, but the amount of noise will depend on the specific model and the installation. PIV units typically include a low-wattage fan that is designed to circulate air throughout the property. The noise level of the fan can vary depending on factors such as the size of the fan, the speed of the fan, and the quality of the materials used in the construction of the unit.

However, many PIV units are designed to be as quiet as possible, with noise levels ranging from 15 to 30 decibels, which is roughly equivalent to the noise level of a whisper or the sound of rustling leaves. Some manufacturers also offer PIV units with additional noise-reducing features, such as insulated ducting or low-noise motors.

It's important to choose a PIV unit with a noise level that is appropriate for the location where it will be installed. For example, if the unit will be installed in a bedroom or other quiet area, it may be necessary to choose a unit with a very low noise level.

Overall, while PIV systems can produce some noise, they are typically designed to be as quiet as possible, and many models offer noise-reducing features to minimize any disturbance to the occupants of the property.

How Much Does a PIV Unit Cost to Run?

PIV units run constantly at a very low speed which keeps the running costs extremely low. Running costs can be as little as £20 per year as power consumption can be controlled between 2.25W and 14.5W.

The cost of running a heated positive input ventilation unit (PIV) can vary depending on several factors, including the size of the unit, its energy efficiency, the climate, and the frequency of use.

In general, a PIV unit with an integrated heating system will consume more energy than a standard non-heated PIV unit. According to a study by Nuaire, a leading manufacturer of PIV units, the average annual cost of running a heated PIV unit is around £100-£150 per year in the UK. However, this can vary depending on the size of the unit and the energy efficiency of the system.

It's worth noting that energy costs can vary greatly depending on your location and local electricity prices. It's best to consult with the manufacturer of the PIV unit or a local energy provider for more accurate information on the cost of running a specific unit in your area.

Are PIV Units Worth It?

Positive Input Ventilation (PIV) units can be an effective way to improve indoor air quality and reduce issues related to dampness and condensation in a home. They work by introducing fresh air from outside, which is filtered and heated if necessary, and then distributed throughout the property to improve air circulation and ventilation.

The benefits of PIV units can include:

1. Reduced condensation: By improving air circulation and increasing ventilation, PIV units can help to reduce condensation and dampness in the home, which can help to prevent mould growth and protect the health of residents.

2. Improved indoor air quality: PIV units can help to filter out pollutants and allergens from the air, which can improve the overall indoor air quality and reduce the risk of respiratory problems.

3. Energy-efficient: PIV units can be energy-efficient, especially when compared to other types of ventilation systems. They typically use low-wattage fans and can recycle heat from the loft space, which can help to reduce energy bills.

However, whether or not a PIV unit is worth it will depend on a variety of factors, including the size of the property, the severity of any existing damp or ventilation problems, and the cost of the unit and installation. It's best to consult with a qualified professional to determine whether a PIV unit is the right solution for your home's needs.

What are The Disadvantages of PIV?

While Positive Input Ventilation (PIV) systems can offer several benefits, there are also some potential disadvantages to consider. These can include:

1. Initial cost: PIV units can be more expensive to install than other types of ventilation systems, such as extractor fans. The cost will depend on the size of the property and the complexity of the installation.

2. Noise: PIV units can produce some noise, especially if they are installed in a bedroom or other quiet area. It's important to choose a unit with a low noise level or to ensure that the unit is installed in a location where noise is not a concern.

3. Maintenance: PIV units require regular maintenance to ensure that they continue to function effectively. Filters need to be cleaned or replaced regularly, and the unit should be inspected periodically for signs of wear and tear.

4. Energy consumption: While PIV units can be energy-efficient, they still require electricity to operate. This can add to your energy bills, especially if the unit is not used correctly or if it is not set up appropriately for your property.

5. Drafts: In some cases, PIV units can create drafts, especially if they are not installed correctly or if they are not set up correctly for the right size property. This can lead to discomfort for residents and may reduce the effectiveness of the unit.

It's important to consider these potential disadvantages when deciding whether a PIV unit is the right solution for your property. Consulting with a qualified professional can help you to determine whether a PIV unit is appropriate for your needs, and what type of unit would be most suitable for your property.

PIV Units for Flats

There are multiple surface mounting option PIV units for flats so the lack of a loft space is really no problem.