Grade three insulation what does it really mean?

When a motorhome or caravan is constructed, the manufacturer will give a great deal of thought to insulation. With this in mind, some units are classed as having grade three insulation. Others are insulation grade two. So what exactly is meant by the term grade three insulation?

A motorhome or caravan that is constructed with insulation grade three should be able to maintain an interior temperature of +20 degrees centigrade internally, with the heating system on, when the outside temperature is -15 degrees centigrade. It is as simple as that. This is not a reference to “winterisation” or a “winterised unit”. That is a different thing altogether.

Grade three insulation

Grade three insulation is a Kon-tiki feature.

My present motorhome, the Swift Kontiki 679 is a model with insulation grade three. During the winter of 2010-2011, outside temperatures were -18 degrees centigrade but inside was warm and snug. It was also way over twenty degrees centigrade.

Of course, if you throw enough energy at something, then any temperature inside should be achievable. For example a glass greenhouse could probably be maintained at twenty degrees centigrade when it is -15 outside. However, tremendous amounts of heat energy is likely to be needed.

Grade three insulation vs grade two?

On a similar theme, a motorhome or caravan that is constructed with insulation grade two should be able to maintain an internal temperature of +20 degrees centigrade when the outside temperature in zero degrees centigrade.

A motorhome that is fully winterised generally has all plumbing, (ie fresh water tank, waste water tank, drain pipes and fresh water pipes) located in a twin floor. The space between the twin floor usually has a heat source too. It is possible that you could buy a motorhome or caravan with insulation grade three only to find that the fresh water tank is underslung and therefore possibly at risk of freezing in the wintertime. So, in reality, the motorhome or caravan would be warm and snug internally, but the water tank could be frozen solid. The point here being that the insulation grade of the unit is not the same as being “winterised”.

Some buyers may however find the insulation grade useful when considering a vehicle for all year round use.

The Kon-tiki is a British built motorhome, manufactured by Swift. This link to the Swift website will explain a little more about the concept of grade three insulation.




  1. Craig Gadd September 23, 2017
    • Motorhome Voyager October 13, 2017

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Austria Belgium France Germany Italy Luxembourg Mountain passes Spain Switzerland U.K.
Bad Krozingen spa
Bad Krozingen spa, Germany

Warm weather with unbroken sunshine is our passport to visit the...

Waterfalls Italy
Cascata delle Marmore – the Marmore Waterfalls

The “Cascata delle Marmore” (Marmore waterfalls) are adjacent to our present...

Tax free shopping Switzerland Samnaun
Duty free shopping in Samnaun

Samnaun us a high altitude alpine village in Switzerland. Access to...

Camper stops Campsite Reviews
Camping les portes D'Alsace
Camping les portes D’Alsace

In a convenient location close to the A4 Paris-Strasbourg motorway, the...

Bad Krozingen camperstop
Bad Krozingen camperstop

Team Voyager is currently in residence at the Bad Krozingen camperstop....

Camping Boschetto di Piemma
Camping Boschetto di Piemma, San Gimignano

Team Voyager is in residence at Camping Boschetto di Piemma, San...

Alde How to... Toll free routes
The cost of a longer motorhome holiday
Our toll free routes

By popular demand, here is a summary of the toll free...

Pet passport
Pet passport scheme – Sydney’s travels!

In recent weeks, the “Voyager” has received many enquiries about Sydney,...

Route to Lake Garda avoiding tolls
Another route to Lake Garda avoiding tolls!

Ah, here we go again, a route to Lake Garda avoiding tolls!...

Twin door fridge motorhome
Dometic RMD 10 series refrigerator

Our new Kon-tiki 675 features a Dometic RMD 10 series refrigerator....

Electric hot plate in a motorhome?

With the refurbishment of our Scania Irizar coach nearing completion, one...

Thule Omnistep not working

Sincere apologies for the timing of this post! Our Omnistep stopped...

Swiss Lux low wattage kettle
Swiss Lux low wattage kettle

It’s fair to say that most UK campsites offer around ten...

Company Reports Ferry good days out My motorhomes
Detached retina surgery
Detached retina operation!

What, you may ask, does a detached retina operation have to...

2019 Swift Kontiki
Swift Kontiki 675 – review

The Swift Kontiki 675 is a six berth motorhome from UK...

Coach motorhome conversion
Belt and braces maintenance for our coach conversion

You are possibly wondering why things have been so quiet on...