Cormar Riva and Cloud 9 Cumulus: combined TOG for underfloor heating
The combined TOG for Cormar Riva over Cloud 9 Cumulus, worked against the UHMA underfloor heating rule.
Combined against the UHMA 2.5 TOG underfloor-heating limit. Under 1.5 also suits a low-temperature heat pump.
| Carpet | Cormar Riva (1.8 TOG) |
|---|---|
| Underlay | Cloud 9 Cumulus (3.1 TOG) |
| Published sum | 4.9 TOG |
| UHMA in-situ correction | minus 1 TOG |
| Combined in-situ TOG | 3.9 TOG |
| Standard UFH limit | 2.5 TOG |
| Heat pump target | under 1.5 TOG |
Cormar Riva is rated 1.8 TOG and Cloud 9 Cumulus is rated 3.1 TOG. Laid together the combination is what the underfloor heating has to warm through.
The published TOG figures add to 4.9, and even after the UHMA 1 TOG in-situ correction the pair sits at 3.9 TOG, 1.4 TOG over the limit. The carpet is fine; the underlay is doing the damage. Keep Cormar Riva and drop to a low-TOG underlay such as Duralay Heatflow for Carpet (0.75 TOG) or Duralay Technics 5 (0.56 TOG), which brings the combined figure back into range.
Sources: UHMA guidance on underfloor heating with carpet and underlay (combined-TOG rule) · How to calculate a combined TOG (UHMA formula, worked) · Cormar Carpets published carpet TOG values · Ball & Young Cloud 9 Cumulus underlay specification