What do the labels on these pages mean?
SEER 9.5 is the seasonal cooling figure on the Daikin Perfera 2.5 kW registration, and it is why 400 hours at the Ofgem cap comes to £27.71 (checked 25 Sep 2026). The rows below are the other labels used on this site.
computed
Labels
| Term | Meaning on this site |
|---|---|
| LwA | A-weighted sound power of the unit, the figure MCS 020a puts into Lp = Lw + 10·log10(Q / (4·π·r²)) − barrier. Manufacturer-declared when it comes from EPREL. |
| Lp | A-weighted sound pressure at a point, in dB(A). The legal test uses Lp at 1 m outside the neighbour’s window, not a catalogue ‘at 1 m’ marketing line. |
| dB(A) | Decibels, A-weighted. England and Wales: 37 dB(A) in MCS 020a. Scotland’s cited MCS 020 limit is 42.0 dB(A). |
| SEER | Seasonal cooling efficiency on the energy label. The Perfera registration used here is SEER 9.5: about 9.5 kWh of cooling per 1 kWh of electricity across the label season. |
| SCOP | Seasonal heating efficiency. Daikin UK describes it as the heating counterpart of SEER. This site’s summer £ figure uses SEER or EER, not SCOP. |
| Q | Directivity. MCS 020a: Q2 is one reflecting surface, Q4 two, Q8 three. More than three reflecting surfaces does not meet the method. |
| MCS 020a | MCS 020 a) Air Source Heat Pump Sound Calculation, Issue 1.1. The noise method Class G points at in England and Wales. |
| Class G | England: Schedule 2, Part 14, Class G of the GPDO 2015, as amended by SI 2025/560. Wales: its own Class G in the Welsh order. |
| 6H | Scotland: Class 6H of the GPDO (Scotland) 1992. Heating or hot water only. Cooling is not covered by the class. |
| Conservation area | In England, Class G still applies inside a conservation area unless the unit is on a wall or roof that fronts a highway, or nearer the highway than the building. |
| Article 4 | A direction can remove a permitted-development right. It counts only when the direction covers this class. The presence of some other direction does not. |
| BUS | Boiler Upgrade Scheme. Ofgem: “£2,500 for air-to-air heat pumps (AAHP) (in residential properties only).” England and Wales. |
| HES | Home Energy Scotland grant and loan. The terms say: “We will not cover: … Air to air heat pumps.” |
| EPREL | European Product Registry for Energy Labelling. SEER, capacity and LwA on model pages are manufacturer-declared registrations. |
| HHSRS | Housing Health and Safety Rating System (England) Regulations 2005. Schedule 1 lists excess heat as exposure to high temperatures. |
| Ofgem price cap | The unit rate in this build is 26.32 p/kWh and the standing charge is 54.83 p/day, direct debit, 1 Oct–31 Dec 2026. |
| Outcode | The outward part of a postcode, such as N1. District pages and the landlord letter use it. It is not a single house. |
Next pages
MCS 020a quotes in the decision contract; Daikin UK size guide; Ofgem cap file; EPREL registrations · 25 Sep 2026 · n=17 · Definitions follow the quoted instrument. SEER is the registered number, not a lab measurement by this site. · updated 25 Sep 2026 · version 1.0.0 · CSV of the values on this page
Source detail
https://www.daikin.co.uk/en_gb/residential/inspiration/articles/air-conditioner-size-guide.html