A question of control

When it comes to ventilation, choosing the right controls can be an important and relatively low cost way to lower the carbon footprint of a building. David Cook, Product Marketing Manager – Non-Residential at Vent-Axia reveals how upgrading controls will improve the performance of existing A/C controllable fans.

The building services industry is driven by a determination to improve energy efficiency and reduce carbon emissions. 

The Government has set clear targets for buildings to become carbon neutral, with public sector non-dwellings required to become zero carbon by 2018 and other non-dwellings needing to comply by 2019. To reach these targets, the regulatory framework has changed and buildings need to meet new efficiency standards.

New-build developments represent a modest percentage of the building stock in this country. According to statistics from the Carbon Trust around 60% of the building stock that will exist in 2050 has already been built, with approximately two million non-domestic buildings in the UK currently accounting for 18% of the country’s total carbon emissions.

Presently, public buildings are required to have a Display Energy Certificate (DEC) on show in the foyer area but commercial buildings are not. There are movements to change legislation to rectify this situation. In June this year, Zac Goldsmith MP tabled a new clause to the Energy Bill which is likely to see all commercial buildings require a DEC with its A-G rating for energy performance, when the Bill becomes law.

Alongside the likely introduction of DECs, the CRC Energy Efficiency Scheme, which is currently being simplified by DECC, offers reputational, behavioural and financial drivers to encourage the uptake of energy efficiency. Currently, any company using more than 600 megawatts of electricity per year has to buy allowances at £12 for every tonne of CO2 emitted.

Improve performance

The implications are clear. Significant progress in reaching our carbon targets can be achieved if we improve the performance efficiency of our existing building stock. Drivers and incentives are being put in place to encourage these improvements. At the same time, this retrofit market represents an important business opportunity for contractors and consultants.  

It’s not just that these improvements make good environmental sense either. Improving the efficiency of our building stock at a time of surging energy prices makes increasingly good financial sense. Only recently British Gas announced quite staggering rises with the cost of gas increasing by 18% and electricity by 16%. This news followed the decision by Scottish Power to introduce similar hikes, and other energy suppliers are likely to follow suit.

With budgets under pressure and the requirements to meet carbon efficiency targets becoming tighter, companies are being squeezed from both sides. So what improvements can be made? Relatively low-cost capital investment decisions can make a significant difference. Take ventilation as an example.

Make the change

The vast majority of existing commercial and public buildings are equipped with inefficient, energy hungry A/C fans, operating with either no or relatively unsophisticated control. Sometimes, it may be seen as impractical or plainly too expensive to take out and replace these fans with new, more efficient models.

A cost-effective approach is offered by a new breed of ventilation controllers on the market which are designed to ensure that the ventilation rates delivered by the fans are equal to the occupancy levels in the buildings they are used in. This type of demand control ventilation can help make significant energy and cost savings to the occupiers while ensuring the ventilation system is used effectively and correctly. 

These new controllers are capable of bringing much better control to existing A/C fans installed in many typical HVAC applications. They allow contractors to adjust ventilation operation according to demand readings gathered from CO2, temperature or constant pressure sensors, located in the space. They also offer the capability to adjust and control fan speeds remotely to ensure more efficient operation and reduced fuel costs.

Versatility for specific applications is also important. Options available within the Vent-Axia eDemand range of controllers, for example, includes the Electronic Voltage Controller, Frequency Inverter single to three phase, Frequency Inverter three phase and Frequency Inverter single phase to cover most bases. All eDemand controllers offer minimum and maximum speed set points, two programmable relay outputs, fault condition and master/slave. The controllers also incorporate LCD multi-function displays with menu language options including English, German, French and Italian. The Electronic Voltage Controller also features a mains switch with by-pass function. All the controllers can be pin protected to save user settings and the Frequency Inverters are complete with integrated SINEFILTER for long-life operation.

Effective control

Vent-Axia has also recently launched eDemand Auto Changeover Panels as part of the range for effective control over a wide range of standard AC speed controllable twin fans. The changeover panels have been designed to complement the new eDemand controllers and are fully compatible for installation with these products.

Installation time and disruption is often a serious concern for contractors and their clients in the retrofit market. The easier manufacturers can make the project, the better for all concerned. With this at the forefront of manufacturers’ minds, the latest demand controllers are designed for easy installation, set up and configuration. Quick start-up can be ensured with each device having pre-programmed modes.

In the light of ambitious Government targets, tightening regulations and the spiralling cost of energy, building owners and occupiers are under increasing pressure to improve the efficiency of their estates. Demand ventilation as a concept is proven to improve ventilation efficiency and reduce carbon emissions. Thanks to the availability of an affordable, retrofit option for existing A/C fans, contractors and consultants can help their clients meet these requirements and help our buildings shape up to a low carbon future that lies ahead for us all.



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