Like for like?
Nowadays when we are looking to replace a fridge or washing machine, it has become second nature to put energy efficiency to the top of our shopping list by looking only at ‘A’ and ‘B’ labelling options.
This is both so that we can save on the ongoing running costs, as energy prices continue to rocket, as well as to salve our consciences as we know that these well rated goods place far less strain on the environment.
We would never, for example, walk into a shop and look at the identical piece of equipment we had bought some 5-10 years previously as we would be only too aware that technological advances would mean that we could now buy a much more efficient product. But is the same true of other, perhaps even more fundamental energy using products that are to be found in every single commercial building in the UK?
Pumps have, for decades been central to many facets of commercial buildings and operate to maintain the ideal ambient temperature, work to maintain sufficient pressure, provide a boost to the supply when required as well as getting clean water onto site and dirty water away, to name but a few of their better known roles. In this way they play a pivotal role in maintaining a buildings internal equilibrium and therefore its inhabitant’s wellbeing. With a replacement cycle of approximately 15 years, the decisions made, when the point of replacement is reached have important long-term energy ramifications.
The replacement cycle
As a pump manufacturer we are very aware that the entire replacement issue can be a grey area that often slips under the energy use/best practise radar. It is often service support staff who make the decision as to when a pump has arrived at the end of its useful life, perhaps due to the complexity of repair or the unavailability of particular spare parts. Then it is all too often a scenario where the details are simply reading off the pump plate and the identical pump is reordered, or where this has been discontinued, the closest alternative is requested.
The best solution?
The pump industry, like many engineered solutions driven businesses, is constantly evolving. It can be likened to the motor industry in many ways, especially when it comes to the dynamic pace of change that it has experienced in the past 20 years. However, even though there are similarities, most people change their car every 2/3 years so the pumps lifecycle at 15 years makes it even more important that the right decision is made when the replacement cycle does come around.
What to consider
When the pump or pump set was first specified, it would probably have been sized to meet an original duty or flow against a pressure, with an additional 10% leeway, purposely built in to cover all eventualities. This over-sizing was (and in some instances still is) common practice and we would estimate that 95% of the current installed pump base, in HVAC applications in particular, is incorrectly sized due to not only the addition of sizing-in for an added comfort factor, but also because pumps are sized based on maximum demand (even though pumps will only need to work near the end of their curve for approximately 5% of their lifespan).
So the first step should be to review the current system requirements as this will often lead to a more efficient pump selection that will offer the benefit of reduced energy consumption.
Once the direct duty has been ascertained, the next step is to check out the most energy efficient solution currently available to answer the present need. Heating circulator pumps make up the majority of the replacement market within commercial services and today glandless circulators are the favoured choice because of their compact design and low maintenance. Glanded mechanical seal style products are however more efficient and can be fitted as a direct replacement for glandless circulators in some cases.
As it is the motor that is the energy sapping aspect of the pump, special attention should be given to this aspect and where conventional motors are used these should be EFF1 rated or better. Many pump manufacturers charge their customers extra for this option, but with a Grundfos solution these extra efficient motors come as an integral part of our standard offering.
With a variable volume system, permanent magnet circulators are today’s choice because they deliver significant energy savings over older style pumps as they automatically adjust to match the system demands. The sums really do stack up – a 20% reduction in speed returns a 50% reduction in energy consumption and a 50% reduction translates into a huge 87% saving in electrical consumption – all based on cube law principles.
At your service
Ongoing servicing issues are not something that is frequently considered as part of the equation when selecting a replacement pump, yet this can often be an important consideration. In the instance of glandless circulators, replacement heads are readily available and are simple to change. On glanded pumps the two main service items are the motor and the mechanical seal and newer pump designs facilitate easier replacement of these ‘wear’ components.
Opting for a major pump manufacturer like Grundfos when replacing pumps will mean that they will be able to offer long-term support for their products through a national service back-up and will also continue to offer a wide range of dedicated service kits and replacement motors for their ranges, often at very short leadtimes. This assurance is something that is rarely sought at the time of purchase but that can have nightmarish consequences when the pump fails or needs emergency servicing.
Mind the gap
With space in commercial buildings at more and more of a premium, the choice of in-line or end-suction style products becomes a more important consideration. Solutions normally need to offer the least pipe work modifications possible but access to the motor is important as it is taking into consideration the need to use cranes or hoists.
Re-selection made easy
To make it easier for customers to select a replacement pump that offers the maximum levels of efficiency Grundfos offer an on-line selection tool (at http://www.grundfos.co.uk/) called WebCAPS. This tool allows people to make the most efficient selection both in the instance of a new pump or where a replacement is needed.
When the ‘Replacement’ option is selected from either the web site (WinCAPS, a selection tool, is also available on CD), the user is invited to input a number of key pieces of information including what the current pump type they are replacing and if they want the replacement decision to be based on energy cost considerations.
The programme will then calculate the actual energy and cost savings that can be made by opting for a better efficiency pump and thus take all of the guess work out of the replacement equation.
Pump efficiency is improving due to many factors including improvements in pump design, the achievement of improved tolerances in manufacturing, better testing and when in the field, ease of service, accessibility of spare parts
as well as a wide range of ancillary products that support the infrastructure they sit within.
Make sure you take advantage of the latest technological advances by choosing to reselect every time a pump needs to be replaced. That way you will know you have achieved a win/win – by reducing energy usage and decreasing the buildings’ carbon footprint.