This article gives dozens of worked ESFR and CMSA solutions organised by ceiling height — 7.6 m, 9.1–10.7 m, 12.2 m and above 12.2 m — for both non-storage process (FH) and storage (HHS1–HHS5) occupancies, based on the actual design tables of EN 12845-2:2024 (Tables 7 to 21). Every row states the K-factor, the number of operating sprinklers, the minimum operating pressure and the source table. Values are for information; the full text of the standard governs any actual design.
General Rules (Applying to All Tables)
- ESFR is wet pipe only (even a dry pendent ESFR counts as a wet system, Cl. 6.5). CMSA may be wet or dry; dry CMSA uses 141 °C standard-response upright sprinklers on terminal (tree-type) pipework, and gridded or looped arrangements are not permitted (Cl. 6.7.2).
- Water supply duration (Table 6): depends on the number of ceiling sprinklers in the design — 60 minutes for 9, 10 and 12 sprinklers, 90 minutes for 15 and 16, 120 minutes for 20 to 30. CMSA protection of roll paper needs 120 minutes and of rubber tyres 180 minutes; the special dry CMSA designs of Table 21 state their own duration (90 or 120 minutes); combined ceiling and in-rack designs need at least 60 minutes.
- Maximum roof or ceiling slope is 10 degrees (Cl. 5.2.1); beyond that a flat false ceiling, an in-rack solution, or a design to EN 12845 (CMDA) is required.
- Interpolation and extrapolation are prohibited (Cl. 6.1) — for an intermediate case use the next row up (higher ceiling); the criteria for a given ceiling height may be used at a lower ceiling provided no other parameter changes.
- Special-requirement ESFR designs (Cl. 6.6.1.2) have a minimum design area of 71 m²; 9 sprinklers means 3 sprinklers on each of 3 adjacent range pipes.
- US equivalents of the K-factors: K160 (K11.2), K200 (K14.0), K240 (K16.8), K280 (K19.6), K320 (K22.4), K360 (K25.2), K400 (K28.0), K480 (K33.6).
1. Non-Storage Process (FH) — CMDA
In FH3 to FH5 ESFR and CMSA are prohibited; CMDA (density and area, EN 12845 Table 3) is used. Where ESFR or CMSA is used in FH1 or FH2, it is designed on an HHS1–HHS3 basis (the storage tables below) regardless of the actual commodity category. Process CMDA criteria:
| Class (→FH) | Density | Design area, wet (m²) | Design area, dry (m²) | Concept | Reference |
|---|---|---|---|---|---|
| LH (→FH1) | 2.25 mm/min | 84 | not allowed (use OH1) | CMDA | EN 12845 Table 3 |
| OH1 (→FH1) | 5.0 mm/min | 72 | 90 | CMDA | EN 12845 Table 3 |
| OH2 (→FH2) | 5.0 mm/min | 144 | 180 | CMDA | EN 12845 Table 3 |
| OH3 (→FH2) | 5.0 mm/min | 216 | 270 | CMDA | EN 12845 Table 3 |
| OH4 (→FH3) | 5.0 mm/min | 360 | not allowed (use HHP1) | CMDA (ESFR/CMSA PROHIBITED) | EN 12845 Table 3 · EN 12845-2 Cl. 6.2 |
| HHP1 (→FH3) | 7.5 mm/min | 260 | 325 | CMDA (ESFR/CMSA PROHIBITED) | EN 12845 Table 3 · Cl. 6.2 |
| HHP2 (→FH4) | 10.0 mm/min | 260 | 325 | CMDA (ESFR/CMSA PROHIBITED) | EN 12845 Table 3 · Cl. 6.2 |
| HHP3 (→FH5) | 12.5 mm/min | 260 | 325 | CMDA (ESFR/CMSA PROHIBITED) | EN 12845 Table 3 · Cl. 6.2 |
| HHP4 (not in Table A.1) | Deluge | — | — | Special consideration; deluge systems are outside the scope of EN 12845 | EN 12845 Table 3 note |
2. Storage (HHS) — Ceiling Around 7.6 m (Storage Around 6.1 m)
Some CMSA rows below are given for a 9.1 m (or 7.9 m) ceiling; under Clause 6.1 the criteria for a higher ceiling may be used at a 7.6 m ceiling provided no other parameter changes. Values in brackets are maximum storage / maximum ceiling height.
ESFR options
| Commodity | Concept | K-factor & orientation | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|
| HHS1–3 | ESFR ceiling-only | K200 pendent | 12 | 3.4 | Table 7 |
| HHS1–3 | ESFR ceiling-only | K240 pendent | 12 | 2.4 | Table 7 |
| HHS1–3 | ESFR ceiling-only | K320 pendent | 12 | 1.7 | Table 7 |
| HHS1–3 | ESFR ceiling-only | K360 pendent | 12 | 1.0 | Table 7 |
| HHS1–3 | ESFR ceiling-only | K200 upright | 12 | 3.4 | Table 7 |
| HHS1–3 | ESFR ceiling-only | K240 upright | 12 | 2.4 | Table 7 |
| HHS1–3 | ESFR special (fewer sprinklers) | K200 pendent | 9 | 2.4 | Table 10 |
| HHS1–3 | ESFR special | K240 pendent | 9 | 1.7 | Table 10 |
| HHS1–3 | ESFR special | K320 pendent | 9 | 1.4 | Table 10 |
| HHS1–3 | ESFR special | K360 pendent | 9 | 1.4 | Table 10 |
| HHS4 | ESFR ceiling-only | K200 pendent | 12 | 3.4 | Table 7 |
| HHS4 | ESFR ceiling-only | K240 pendent | 12 | 2.4 | Table 7 |
| HHS4 | ESFR ceiling-only | K320 pendent | 12 | 5.2 | Table 7 |
| HHS4 | ESFR ceiling-only | K360 pendent | 12 | 4.1 | Table 7 |
| HHS4 | ESFR special | K320 pendent | 10 | 1.7 | Table 10 |
| HHS4 | ESFR special | K360 pendent | 10 | 1.4 | Table 10 |
| HHS5 | ESFR special | K200 pendent | 12 | 5.2 | Table 10 |
| HHS5 | ESFR special | K360 pendent | 9 | 1.7 | Table 10 |
CMSA alternatives
| Commodity | Concept | K-factor & orientation | System | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|---|
| HHS3 (6.1/9.1 m) | CMSA block (STC1) | K240 upright | Wet | 15 | 1.5 | Table 16 |
| HHS3 (6.1/9.1 m) | CMSA block (STC1) | K280 pendent | Wet | 15 | 1.1 | Table 16 |
| HHS3 (6.1/9.1 m) | CMSA block (STC1) | K360 pendent | Wet | 15 | 0.7 | Table 16 |
| HHS4 | CMSA (5.5/7.9 m) | K160 upright | Wet | 15 | 3.4 | Table 16 |
| HHS4 | CMSA (6.1/9.1 m) | K240 upright | Wet | 15 | 1.5 | Table 16 |
| HHS5 | CMSA (5.5/7.9 m) | K160 upright | Wet | 15 | 3.4 | Table 16 |
| HHS5 | CMSA (5.5/7.9 m) | K240 upright | Wet | 15 | 1.5 | Table 16 |
| Up to HHS4 (STC1/2, 6.1/7.6 m, aisle 1.2 m) | CMSA dry — special | K160 upright | Dry (60 s) | 20 | 3.5 | Table 21 |
3. Storage (HHS) — Ceiling Around 9.1 to 10.7 m
ESFR options
| Commodity | Concept | K-factor & orientation | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|
| HHS1–3 (9.1 m) | ESFR ceiling-only | K200 pendent | 12 | 3.4 | Table 7 |
| HHS1–3 (9.1 m) | ESFR ceiling-only | K360 pendent | 12 | 1.0 | Table 7 |
| HHS1–3 (9.1 m) | ESFR special | K200 pendent | 12 | 3.5 | Table 10 |
| HHS1–3 (9.1 m) | ESFR special | K320 pendent | 9 | 1.4 | Table 10 |
| HHS1–3 (10.7 m) | ESFR ceiling-only | K200 pendent | 12 | 5.2 | Table 7 |
| HHS1–3 (10.7 m) | ESFR ceiling-only | K240 pendent | 12 | 3.6 | Table 7 |
| HHS1–3 (10.7 m) | ESFR ceiling-only | K320 pendent | 12 | 2.4 | Table 7 |
| HHS1–3 (10.7 m) | ESFR ceiling-only | K360 pendent | 12 | 1.4 | Table 7 |
| HHS1–3 (10.7 m) | ESFR special | K320 pendent | 12 | 2.0 | Table 10 |
| HHS1–3 (10.7 m) | ESFR special | K360 pendent | 12 | 1.6 | Table 10 |
| HHS4 (9.1 m) | ESFR ceiling-only | K320 pendent | 12 | 5.2 | Table 7 |
| HHS4 (9.1 m) | ESFR special | K320 pendent | 10 | 3.5 | Table 10 |
| HHS5 (9.1 m; exposed expanded plastics conditions with vertical barriers) | ESFR ceiling-only | K360 pendent | 12 | 2.0 | Table 7 |
| HHS5 (9.1 m) | ESFR special | K360 pendent | 12 | 2.8 | Table 10 |
CMSA alternatives (STC1 block and STC4 rack)
| Commodity | Concept | K-factor & orientation | System | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|---|
| HHS1/2 (7.6/9.1) | CMSA block (STC1) | K280 pendent | Wet | 15 | 1.1 | Table 15 |
| HHS1/2 (7.6/9.1) | CMSA block (STC1) | K360 pendent | Wet | 15 | 0.7 | Table 15 |
| HHS1/2 (7.6/9.1) | CMSA block (STC1) | K360 upright | Wet | 12 | 1.4 | Table 15 |
| HHS1/2 (7.6/10.7) | CMSA block | K160 upright | Wet | 15 | 1.7 | Table 15 |
| HHS1/2 (7.6/10.7) | CMSA block | K160 upright | Dry | 25 | 1.7 | Table 15 |
| HHS1/2 (7.6/10.7) | CMSA block | K240 upright | Wet | 15 | 1.0 | Table 15 |
| HHS1/2 (9.1/10.7) | CMSA block | K280 pendent | Wet | 15 | 1.7 | Table 15 |
| HHS1/2 rack (6.1/9.1) | CMSA rack (STC4) | K280 pendent | Wet | 15 | 1.1 | Table 17 |
| HHS1/2 rack (6.1/9.1) | CMSA rack (STC4) | K360 pendent | Wet | 15 | 0.7 | Table 17 |
| HHS3 (7.6/9.1) | CMSA rack (STC4) | K280 pendent | Wet | 15 | 1.1 | Table 19 |
| HHS3 (7.6/9.1) | CMSA rack (STC4) | K360 pendent | Wet | 15 | 0.7 | Table 19 |
4. Storage (HHS) — Ceiling Around 12.2 m
ESFR options
| Commodity | Concept | K-factor & orientation | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|
| HHS1–3 | ESFR ceiling-only | K240 pendent | 12 | 3.6 | Table 7 |
| HHS1–3 | ESFR ceiling-only | K320 pendent | 12 | 2.8 | Table 7 |
| HHS1–3 | ESFR ceiling-only | K360 pendent | 12 | 1.7 | Table 7 |
| HHS1–3 | ESFR special | K200 pendent | 12 | 5.2 | Table 10 |
| HHS1–3 | ESFR special | K240 pendent | 12 | 3.6 | Table 10 |
| HHS1–3 | ESFR special | K320 pendent | 9 | 3.5 | Table 10 |
| HHS1–3 | ESFR special | K360 pendent | 9 | 2.8 | Table 10 |
| HHS4 | ESFR ceiling-only | K320 pendent | 12 | 5.2 | Table 7 |
| HHS4 | ESFR ceiling-only | K360 pendent | 12 | 4.1 | Table 7 |
| HHS4 | ESFR special | K360 pendent | 12 | 4.1 | Table 10 |
| HHS5 | ESFR ceiling-only | K360 pendent | 12 | 4.1 | Table 7 |
| HHS5 | ESFR special | K360 pendent | 20 | 5.2 | Table 10 |
CMSA alternatives
| Commodity | Concept | K-factor & orientation | System | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|---|
| HHS1/2 (7.6/12.2) | CMSA block (STC1) | K360 pendent | Wet | 15 | 1.6 | Table 15 |
| HHS1/2 (10.7/12.2) | CMSA block (STC1) | K280 pendent | Wet | 15 | 2.1 | Table 15 |
| HHS1/2 (10.7/12.2) | CMSA block (STC1) | K360 pendent | Wet | 15 | 1.6 | Table 15 |
| HHS1/2 (10.7/12.2) | CMSA block | K360 upright | Dry (25 s) | 24 | 1.0 | Table 15 |
| HHS1/2 rack (10.7/12.2) | CMSA rack (STC4) | K280 pendent | Wet | 15 | 2.1 | Table 18 |
| HHS1/2 rack (10.7/12.2) | CMSA rack (STC4) | K360 pendent | Wet | 15 | 1.6 | Table 18 |
| HHS1/2 rack (10.7/12.2) | CMSA rack (STC4) | K360 upright | Dry (25 s) | 24 | 1.0 | Table 18 |
| HHS3 (10.7/12.2) | CMSA rack (STC4) | K360 pendent | Wet | 15 | 1.6 | Table 19 |
| HHS1/2 (10.7/12.2; aisle 1.8 m) | CMSA dry — special | K360 upright | Dry (20 s) | 12 | 3.5 | Table 21 |
| HHS1 (10.7/12.2; aisle 2.4 m) | CMSA dry — special | K160 upright | Dry (30 s) | 36 | 3.8 | Table 21 |
5. Storage (HHS) — Above 12.2 m (13.7, 15.2 and 16.8 m)
At a 13.7 m ceiling ESFR uses K320/K360 pendent; at 15.2 m and 16.8 m Table 7 offers only pendent K400/K480, while the Table 11 special-requirement designs use pendent K320 to K480. CMSA at these heights is available only as dry, upright K360/K480 (Tables 18 and 21). Aisle width and ceiling-to-deflector distance become the critical constraints, and the K400/K480 rows exclude multiple-row racks.
| Class & ceiling | Concept | K-factor & orientation | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|
| HHS1–3 (13.7 m) | ESFR ceiling-only | K320 pendent | 12 | 2.8 | Table 7 |
| HHS1–3 (13.7 m) | ESFR ceiling-only | K360 pendent | 12 | 2.8 | Table 7 |
| HHS1–3 (15.2 m) | ESFR ceiling-only | K400 pendent (aisle 1.8 m) | 12 | 2.8 | Table 7 |
| HHS1–3 (15.2 m) | ESFR ceiling-only | K480 pendent (aisle 1.8 m) | 12 | 3.8 | Table 7 |
| HHS1–3 (16.8 m) | ESFR ceiling-only | K400 pendent (aisle 2.4 m) | 12 | 5.5 | Table 7 |
| HHS1–3 (16.8 m) | ESFR ceiling-only | K480 pendent (aisle 1.8 m) | 12 | 3.8 | Table 7 |
| HHS1–3 (15.2 m) | ESFR special (325 mm) | K320 pendent | 10 | 4.3 | Table 11 |
| HHS1–3 (15.2 m) | ESFR special (325 mm) | K360 pendent | 10 | 3.5 | Table 11 |
| HHS1–3 (15.2 m) | ESFR special (425 mm) | K480 pendent | 9 | 3.8 | Table 11 |
| HHS1–3 (16.8 m) | ESFR special (325 mm / 2.4 m aisle) | K400 pendent | 9 | 5.5 | Table 11 |
| HHS1/2 (12.2/13.7; aisle 1.8 m) | CMSA dry — special | K360 or K480 upright | 12 (dry, 20 s) | 3.5 | Table 21 |
| HHS1/2 (13.7/15.2) | CMSA dry — special | K480 upright (aisle 2.4 m) | 15 (dry, 20 s) | 3.5 | Table 21 |
| HHS1/2 (15.2/16.8) | CMSA dry — special | K480 upright (aisle 2.4 m) | 16 (dry, 20 s) | 3.5 | Table 21 |
| HHS1/2 rack (13.7/15.2) | CMSA rack (STC4) | K480 upright (aisle 2.4 m) | 15 (dry, 20 s) | 3.4 | Table 18 |
| HHS1/2 rack (15.2/16.7) | CMSA rack (STC4) | K480 upright (aisle 2.4 m) | 16 (dry, 20 s) | 3.4 | Table 18 |
6. Special Commodities: Rubber Tyres and Roll Paper
| Commodity | Concept | K-factor & orientation | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|
| Rubber tyres (STC3/4, ≤7.6 m stack, 9.1 m ceiling) | ESFR | K320 pendent | 12 | 1.7 | Table 8 |
| Rubber tyres (≤7.6 m, 10.7 m ceiling) | ESFR | K360 pendent | 12 | 1.7 | Table 8 |
| Rubber tyres (on tread or laced, STC3; ≤7.6 m, 12.2 m ceiling) | ESFR | K360 pendent | 12 | 2.8 | Table 8 |
| Roll paper, heavy/medium (7.6/9.1 m) | ESFR | K360 pendent | 12 | 1.0 | Table 9 |
| Roll paper, heavy (9.1/10.7 m) | ESFR | K360 pendent | 12 | 1.7 | Table 9 |
| Roll paper, heavy (9.1/13.7 m) | ESFR | K320/K360 pendent | 12 | 3.4 | Table 9 |
| Light roll paper (7.6/9.1 m) | ESFR | K200 pendent | 16 | 3.4 (Table 9 also gives 5.2 bar for the same heights in a second row; an inconsistency within the standard) | Table 9 |
| Light roll paper (7.6/12.2 m) | ESFR | K200 pendent | 25 | 5.2 | Table 9 |
7. Combined Ceiling and In-Rack Design
Where the ceiling-only limit is exceeded, in-rack sprinklers are added. Under Clause 6.6.2.1.1 (open-frame racks, ceiling up to 13.7 m, K200 or larger pendent ceiling ESFR) the in-rack hydraulic calculation is based on the 8 most remote in-rack sprinklers and a minimum flow of 230 l/min; the in-rack and ceiling demands are added, and the water supply duration is at least 60 minutes. The ceiling side (Table 12):
| Commodity | Concept | K-factor & orientation | Sprinklers | Min. pressure (bar) | Reference |
|---|---|---|---|---|---|
| Up to HHS3 | ESFR ceiling + in-rack | K200 pendent | 12 | 5.2 | Table 12 |
| Up to HHS3 | ESFR ceiling + in-rack | K240 pendent | 12 | 3.6 | Table 12 |
| Up to HHS3 | ESFR ceiling + in-rack | K320 pendent | 12 | 2.8 | Table 12 |
| Up to HHS3 | ESFR ceiling + in-rack | K360 pendent | 12 | 2.8 | Table 12 |
| Up to HHS4 | ESFR ceiling + in-rack | K360 pendent | 12 | 4.1 | Table 12 |
Frequently Asked Questions
Are ESFR sprinklers prohibited in high hazard storage under EN 12845-2?
No - the opposite is true. ESFR and CMSA were developed for high hazard storage (HHS1 to HHS5) and EN 12845-2 protects those classes with them. The prohibition in Clause 6.2 applies to non-storage FH3, FH4 and FH5 occupancies. The clause is even titled Protection of non-storage occupancies. You protect the warehouse with ESFR or CMSA; you cannot protect an FH3 to FH5 production area with them, where the density/area (CMDA) design of EN 12845 applies.
What ESFR options are available for HHS1-HHS3 at a 7.6 m ceiling?
From the Table 7 ceiling-only design with 12 sprinklers: K200 at 3.4 bar, K240 at 2.4 bar, K320 at 1.7 bar or K360 at 1.0 bar pendent; upright K200 at 3.4 bar or K240 at 2.4 bar. Using the special-requirement route in Table 10 the count can drop to 9 sprinklers: K200 at 2.4 bar, K240 at 1.7 bar, K320 at 1.4 bar, K360 at 1.4 bar. Fewer sprinklers means a smaller pump and a smaller tank.
Which designs apply at a 12.2 m ceiling?
For HHS1-HHS3, ESFR ceiling-only gives K240 at 12 sprinklers and 3.6 bar, K320 at 12 and 2.8 bar, or K360 at 12 and 1.7 bar (Table 7). The special-condition route gives K320 at 9 and 3.5 bar or K360 at 9 and 2.8 bar (Table 10). On the CMSA side, wet K360 pendent at 15 sprinklers and 1.6 bar, or dry K360 upright at 24 sprinklers and 1.0 bar with a 25 second water delivery time (Tables 15 and 18). For HHS4 and HHS5 the pressures increase (for example K360 at 12 sprinklers and 4.1 bar).
How are very tall warehouses above 12.2 m protected?
With ESFR ceiling-only: at 13.7 m, K320 or K360 at 12 sprinklers and 2.8 bar; at 15.2 m, K400 at 12 and 2.8 bar or K480 at 12 and 3.8 bar with a minimum 1.8 m aisle; at 16.8 m, K400 at 12 and 5.5 bar with a 2.4 m aisle, or K480 at 12 and 3.8 bar (Table 7). Alternatives are the Table 11 special design reducing to 9 or 10 sprinklers, or dry CMSA systems from Tables 18 and 21 using K480 upright at 15 to 16 sprinklers and 3.4 to 3.5 bar with a 20 second water delivery time and a minimum 2.4 m aisle.
ESFR is wet only and CMSA can be wet or dry - how do I choose?
ESFR may only be used on a wet pipe system; even where dry pendent ESFR sprinklers are used, the installation counts as wet (Clause 6.5). If the warehouse is unheated and freezing is a risk so a dry system is genuinely required, you move to CMSA. On dry CMSA the water delivery time (40 s with 4 sprinklers operating unless a table states otherwise; 20 to 60 s in the tables) and the increased operating sprinkler count both come into play (Clause 6.7.1), and the sprinklers must be 141 degrees C nominal on terminal tree-type pipework, with gridded and looped arrangements prohibited under Clause 6.7.2.
What are the water supply duration and roof slope limits?
The water supply duration depends on the number of ceiling sprinklers in the design (Table 6): 60 minutes for 9 to 12 sprinklers, 90 minutes for 15 to 16, and 120 minutes for 20 to 30; combined ceiling and in-rack designs need at least 60 minutes, and the special dry CMSA designs of Table 21 need 90 or 120 minutes. The maximum roof or ceiling slope is 10 degrees; beyond that you need a flat false ceiling, an in-rack solution, or a design to EN 12845 (CMDA). Interpolation and extrapolation within the tables are also prohibited; for an intermediate case use the next row up (higher ceiling).
When are in-rack sprinklers required?
When the ceiling-only design exceeds its commodity or height limit. For example, under a ceiling up to 13.7 m, single- and double-row open-frame racks with commodities up to HHS4 can be protected by K200 or larger pendent ceiling ESFR supplemented by a single level of wet in-rack sprinklers in the longitudinal flue space. The in-rack hydraulic calculation is based on the 8 most remote in-rack sprinklers and a minimum flow of 230 l/min, and the water supply duration is at least 60 minutes (Clause 6.6.2.1.1 and Table 12).
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Download MEP Calc on the App StoreTS EN 12845-2:2025 (EN 12845-2:2024) — Clauses 6.2, 6.5, 6.6 and 6.7; Tables 7, 8, 9, 10, 11, 12, 15, 16, 17, 18, 19 and 21; Annex A Table A.1. TS EN 12845:2015+A2:2026 and EN 12845-1 (CMDA density and area). Values are given for information; the full text and current edition of the standard govern any actual design.