As well as the tog rating of the carpet you must also consider the tog rating of the underlay.
Carpet less than 1 5 tog.
If you are wanting an underlay for hard flooring then a tog rating of less than 0 4 is ideal.
The previous industry standard has been to advise that the carpet and underlay should not exceed a tog rating of 1 5.
Figures between 0 80 and 1 50 tog have been quoted by manufacturers foam underlays generally have a lower tog rating than felts.
In conjunction with the underfloor heating manufacturers association the carpet foundation carried out a research project.
This theoretically means that shaw carpets in the 4 5 rating would be ideal for areas where there is going to be a lot of traffic like hallways and stairs whilst a rating of less than 2 5 is going to be better in an area that isn t used so.
A lightweight 60 90 oz sponge underlay generally has a relatively low tog rating of 0 5 which makes this type of underlay most suitable for use with underfloor heating.
Suppliers however have stated that carpet must have a thermal resistance of no more than 1 5 1 7 tog.
Please note that the insulating effect of underlay and carpet are to some extent cumulative.
Heat exchange between floor surface and carpet is further insulated by the type of underlay used.
However research conducted by bsria in bracknell and funded by the carpet foundation in conjunction with the underfloor heating manufacturers association uhma has proved conclusively that any carpet can be used with an underfloor heating system without impairing the performance of the system.
This showed that a carpet underlay with a combined thermal resistance of less than 2 5 togs allows underfloor systems to operate efficiently.
Tog values typical brintons 80 wool 20 nylon carpets have a tog value 1 4 and 2 3.
0 n narrow loom widths usually woven only are 0 69m 0 9m l 0m 2 0m.
Tolerances for the dimensions of tufted and woven carpet.
Our 80 wool 20 nylon carpets have a tog value somewhere between 1 4 and 2 3.
The combined value of the carpet and underlay should not exceed 2 5 tog and preferably less than 1 5 for heat pump systems.
As nzs 1385 specifies the following commercial tolerances for.
This is not the case.
We can offer the following information which has been taken from test reports in accordance with bs 4745 two plate test from bttg shirley.
Quality manufacturers will have technical information on their products available to customers.
We would suggest a target tog should be 0 8 or less.
It makes sense to take care in choosing carpet and underlay that will work well with the underfloor heating.