Ground-up heating

Underfloor heating has become increasingly popular within the domestic market. However, there are some common errors homeowners regularly make, and it is up to their installer to ensure they do not fall into the trap. Neil Young, Applications Manager Indoor Climate for Uponor UK, explains more.
Underfloor heating is an affordable luxury for the mass market that offers end users a potentially highly-efficient alternative to traditional heating systems.
However, many homeowners invest large sums of money in renovating or retrofitting a house, or even commissioning and building a new property, and want to have underfloor heating installed throughout. More surprising, though, is the large number of those looking to have underfloor heating installed are prepared to fit the cheapest system they can get their hands on.
Underfloor heating should not be viewed as a one-off purchase, and it is important that an installer makes a customer aware of this from the outset. A cheap underfloor heating system may reduce the overall cost of a refurbishment or self-build project, but it is highly likely that such a system will not offer the levels of energy efficiency, and therefore reduced energy usage, as a more efficient, and probably expensive, system. Importantly, the price differences here are in the region of hundreds of pounds, not thousands. What’s more, the ‘total cost of ownership’ of a system that offers greater energy efficiency, and personal comfort, will far outweigh that of a cheap and inefficient system.
Underfloor heating and floor coverings
For a homeowner, one of the most attractive aspects of a water-based underfloor heating system is its energy efficiency. Water-based systems can use a heat pump to supply water at low temperatures to offer effective heating with minimal energy consumption. However, as soon as any significant floor covering – be it a luxury carpet, vinyl flooring or floor boards – is laid down on top, the system’s energy efficiency is compromised.
Installing an underfloor heating system is a big commitment for a customer, yet a surprising number of people will go through all the effort of the installation and then, for example, fit 22mm oak floor boards on top of 22mm of chipboard. Suddenly the water temperature must be increased to offer the desired level of heating through over 40mm of wood, but doing so effectively erases the energy-saving properties of using a heat pump and water-based system.
Once again, an underfloor heating system’s ‘total life cost’ must be taken into account here as operating at higher water temperatures over an extended period of time will inevitably result in increased energy bills.
While not all coverings will hamper a system’s energy efficiency – tiles for example are an excellent covering that enable a system to operate efficiently at low temperatures – it is highly important for an installer to make clear the best options, especially during the specification stage of a job. More importantly for installer, if a customer’s heating levels are not meeting expectations, it will be the installer who will bear the brunt of their frustration – even if the installation of the heating system itself is in complete working order.
Therefore, despite floor covering not falling under the remit of indoor climate control, advising a homeowner of the fact that a floor covering can noticeably decrease a heating system’s energy efficiency (and therefore increase energy bills) will not only demonstrate an installer’s industry knowledge, but also highlight good aftersales service – a crucial tool for both securing new business and avoiding a bad reputation.
Getting the balance right
One further aspect that both homeowners and installers need to be aware of is balancing the flow rate of an underfloor heating system and the benefits of doing so with energy efficient controls.
Balancing is a vital part of the commissioning process, but, unfortunately, not all home owners are familiar with it and the process is also often overlooked by installers. If a property’s underfloor heating system is not properly balanced, it will operate on a uniform flow rate. This means that all rooms – regardless of size or orientation – will receive the same level of output resulting in some rooms being overheated and others under-heated. In short, the homeowner will once again fail to receive their desired heating output and the installer can be held accountable.
Installers can manually balance each room, but that will only result in the optimum flow rate and heating output for that specific time of the year. Any subsequent seasonal changes will still have to be carried out by an installer, at an extra cost to the homeowner, and additional job time on the part of the installer.
One solution is to install ‘auto-balancing’ controls to the manifold, which replaces the need for the manual balancing of the loops, such as Uponor’s Auto-Balance Technology. Instead of balancing the system for one peak load, it calculates the actual energy needs of the individual rooms over the heating season and adapts to those needs, balancing the system through the changing seasons and throughout the property’s changing usage patterns.  In turn, this gives more even floor temperatures and faster system reactions with lower energy consumption than any standard on/off system.
The benefits of an auto-balanced system are evenly-heated rooms across the whole property with no over – or under – heating issues. Research carried out by Uponor suggests that this type of system is 12% more efficient than an unbalanced or manifold balanced system, which is a clear advantage to the customer in terms of energy cost savings.
For the installer, the benefit of an auto-balanced system is that it takes the variables out of any underfloor heating installation. It is no longer necessary to calculate the impact of room size or whether a room is north or south facing. Crucially, the installer no longer has to make repeat visits to a property to adjust the manifold, a cost that is rarely factored into the cost of a job.
Ultimately, given the increase in demand for underfloor installations in the domestic market, there will be plenty of opportunities for installers to capitalise on the extra business. However, it is also important for installers to make their customers aware of common pitfalls such as the surprisingly costly nature of choosing cheap or inefficient systems, as well as the side-effects of thick floor coverings or poorly balanced systems. Doing so is a great way of staying ahead of the competition and securing important business opportunities.