Piping hot

Underfloor heating combined with air source heat pumps can provide housebuilders and property developers with flexible and efficient heating solutions, as Paul Wakefield of grant UK explains.

Evenly distributing heat upwards into a room, an underfloor heating system maintains optimum room temperatures while also helping the heat source, such as an air source heat pump (ASHP), to work as efficiently as possible.

Underfloor heating provides a pleasant heat throughout the room, leaves walls free for furniture and can add value to a property. It is also easy to install.

Modern underfloor heating systems are straightforward to work with and can be supplied as packs, which are specifically suited to meet a property’s requirements. Some underfloor systems have very low profiles – being just 15 mm in finished floor height, which is beneficial in a number of ways. Firstly, the system can be installed without requiring significant changes to a room’s infrastructure, and such low profile systems are also ideally suited to first floor installations.

Underfloor heating is often not considered for due to certain perceptions, whether it be lengthy installation times or difficulties with laying pipework. In today’s marketplace, there are exciting products that have been designed with the engineer in mind, and which serve to dispel these misconceptions and help make underfloor heating a viable option for many homes.

For example, some underfloor heating systems utilise self-adhesive panels that are compact in size, into which the pipework loops are clipped and a self-levelling compound then laid over the system. The floor can often be walked on the day after laying the compound, and the heat source can be introduced after three days. Such systems make installation extremely quick, reducing the time spent onsite.

One advantageous feature that is not present in all retrofit systems is a system that does not require overboarding, which makes for a simpler installation as the final floor finish can be laid directly on top of the dry screed. Systems that are simple to lay, quick to install and can be completed by a single operative often prove to be the most practical for housebuilders.

Alongside the supply of the underfloor pipework, components and controls, some suppliers will also provide design assistance, including initial system heat loss calculations used for quotation purpose through to full working drawings to complete a package offering. This level of support delivers bespoke assistance which can help ensure that the installation is completed as smoothly as possible.

Heat pumps

Combining heat pumps with underfloor heating is proving to be a popular option. Thanks to legislation, heat pumps are becoming even more efficient. The 2014 EU Fluorinated Greenhouse Gas (F-Gas) Regulations is designed to phase out the use of hydrofluorocarbons, with the introduction of a series of targets designed to limit the use of gases which have the highest Global Warming Potential (GWP).

Heat pumps using R32 refrigerants should be considered, because they have a GWP that is considerably lower than other typical heat pump refrigerants such as R410. They will thus comply with the upcoming legislative targets, future-proof- ing the product.

In addition to having a lower GWP figure of 675, R32 is a single-component refrigerant, which means it has no temperature glide. Refrigerant blends that have two or more components exhibit temperature glide but as R32 only has one molecule in its formation, its saturated liquid and vapor temperatures are the same. By removing the risk for the refrigerant to suffer from glide, the system can recharge and recycle with greater ease, making it more efficient.

Single phase, DC inverter driven ASHPs that incorporate in-built weather compensation and a base tray heating element to prevent ice formation are some of the leading products currently available. With simplified electrics, built-in features as standard, and easily accessible components, heat pumps today are simple to work with.

Ideally, the chosen heat pump should be exceptionally efficient, have compact footprints and operate with low noise levels. It will therefore have minimal impact on its surrounds both aesthetically and acoustically, something which is of great benefit to end-users. Furthermore, heat pumps are often also available with significant guarantees which reflect confidence in the products and deliver greater peace of mind to the homeowner.

Paul Wakefield is managing director of Grant UK