TogCheck
Combined TOG result

Cormar Trilogy Austen and Cloud 9 Contract: combined TOG for underfloor heating

The combined TOG for Cormar Trilogy Austen over Cloud 9 Contract, worked against the UHMA underfloor heating rule.

1.52.5
2.3TOG in situ
Marginal · limit 2.5
Published TOG stack (carpet + underlay)
carpet 1.2
underlay 2.1
limit

Combined against the UHMA 2.5 TOG underfloor-heating limit. Under 1.5 also suits a low-temperature heat pump.

Carpet TOGUnderlay TOGPassMarginalFail
Combined in-situ TOG is 2.3, under the 2.5 TOG limit, so Cormar Trilogy Austen with Cloud 9 Contract is suitable for a standard underfloor heating system. It is above 1.5 TOG, so on a low-temperature heat pump run choose a thinner underlay.
The combined-TOG calculation
CarpetCormar Trilogy Austen (1.2 TOG)
UnderlayCloud 9 Contract (2.1 TOG)
Published sum3.3 TOG
UHMA in-situ correctionminus 1 TOG
Combined in-situ TOG2.3 TOG
Standard UFH limit2.5 TOG
Heat pump targetunder 1.5 TOG

Cormar Trilogy Austen is rated 1.2 TOG and Cloud 9 Contract is rated 2.1 TOG. Laid together the combination is what the underfloor heating has to warm through.

The published TOG figures add to 3.3. The UHMA rule subtracts 1 TOG because tests showed real in-situ resistance runs about a TOG below the paper sum, giving 2.3 TOG. On a heat pump running low flow temperatures the floor has less heat to push, so aim under 1.5 TOG and prefer the thinnest underlay in this range.

Related checks
Cormar Trilogy Austen TOG value1.2 TOGCloud 9 Contract TOG rating2.1 TOGCormar Pimlico with Cloud 9 Contract2.1 TOG, passCormar Primo Textures Ribbed with Cloud 9 Contract2.1 TOG, passCormar Primo Textures Weave with Cloud 9 Contract2 TOG, passCormar Apollo Plus with Cloud 9 Contract2.2 TOG, pass

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 Contract underlay specification