Heat Pumps Today

26 In order to keep on target for nett zero by 2050, the Government has declared gas boilers unwelcome and potentially outlawed them from 2025 in new build properties. Martin Wadsworth, Managing Director of Discrete Heat delves deeper into this suggestion. 600,000 units a year – yeah, right?! It has suggested that by 2030 more than 600,000 boilers per annum will be substituted for heat pumps in the race to reduce the 30% of the UKs total CO 2 emissions attributable to heating. But how realistic is this? Already, some MPs and experts are pushing back citing the cost, shortage of installers and the potential political fallout in forcing homeowners or landlords to upgrade their properties to a minimum of EPC grade C. Some local authorities and social housing providers have also expressed reservations about the renovation and upheaval required to get their housing stock into a position to even accept heat pumps - and that’s before overcoming the objections of tenants who can veto the install. The boiler manufacturers and network gas providers are hardly going to roll over and play dead. They are lobbying hard for hydrogen to provide a cleaner alternative to rival the heat pump roll-out. For heat pumps to get even close to the 600,000 units per annum objective, the heat pump industry needs to address the 2 elephants in the room; June | July 2021 1. The a ordability of upgrading the insulation to ensure adequate heating from a low-grade heat source 2. The practically of retrofitting suitable emitters into an existing property Its larger radiators vs fan coils vs UFH, right? Oversized radiators For radiators to provide the same heat output at a typically 25°C Delta T lower, they would have to have typically, twice the size or surface area. Whilst this may have been seen as an opportunity for radiator manufacturers (who have seen their sales turnover shrink in proportion to the lower heat loads of modern properties), for developers who have gotten used to small rads and subsequently reconfigured their designs to take advantage of the space, this is a bit of a shock. Similarly, home-owners or housing providers have to consider the impact both aesthetically and practically in terms of upsizing their emitters to facilitate the installation of the heat pump. However, simply increasing the size of the radiator does not solve the fundamental issue with radiators as low temperature emitters. This is the fact that despite their name, radiators are primarily convectors and rely on a high temperature di erential between themselves and the occupied space to distribute the heat by air movement. Simply increasing the size to work at lower flow temperatures causes the heat energy to stall and remain in the locale of the radiator leading to occupants complaining of feeling cool unless practically sat in front of them. This phenomenon is well known to the big housing developers as they have had to retrofit sometimes 1 or even 2 extra radiators per room to get better heat distribution at lower flow temperatures on heat pumps. Fan Assisted radiators then? Fan assisted radiators can provide an additional convective boost but, the cooling e ect of blowing the heat around and the 100~200w of electrical energy required to drive them somewhat undercuts the energy e ciency gains of installing a heat pump in the first place. In addition, they tend to be more commercial in appearance and require additional electrical connections, which might make a straight-forward swap out more problematic. S K I R T I N G H E A T I N G