Kjølerøret ligger bak innedelen.

Because Norwegian, like German, very often forms compound nouns by writing them as a single word.

• kjøle = cooling / to cool
• rør = pipe / tube
• kjølerør = cooling pipe
• kjølerøret = the cooling pipe

So English often uses separate words, but Norwegian frequently joins them into one noun.

The ending -et makes the noun definite, meaning the cooling pipe rather than just a cooling pipe.

For a neuter noun like rør, the pattern is:

• et rør = a pipe
• røret = the pipe

Since kjølerør is also treated as a neuter noun, you get:

• et kjølerør = a cooling pipe
• kjølerøret = the cooling pipe

In Norwegian, ligger is often used to describe where something is physically located, especially when it is understood as lying or situated somewhere.

So:

• er = is
• ligger = lies / is located

In many location sentences, Norwegian prefers ligger where English would simply say is.

For example:

• Boken ligger på bordet. = The book is on the table.
• Huset ligger ved sjøen. = The house is by the sea.

So Kjølerøret ligger bak innedelen sounds natural because it describes the physical position of the pipe.

Bak means behind.

In this sentence, it works as a preposition:

• bak innedelen = behind the indoor unit

This is a very common structure:

• bak huset = behind the house
• bak døren = behind the door

So the pattern is:

[thing] + ligger + bak + [place/object]

Innedelen means the indoor unit or the inside part, depending on context.

It is another compound noun:

• inne = inside / indoors
• del = part
• innedel = indoor part / indoor unit
• innedelen = the indoor part / the indoor unit

In heating, ventilation, or air-conditioning contexts, innedelen usually refers to the indoor unit of the system.

Because they belong to different grammatical genders.

In Bokmål, nouns can be:

• masculine
• feminine
• neuter

Here:

• del is usually masculine in this context:
  en del → delen
• rør is neuter:
  et rør → røret

So:

• innedelen = the indoor unit
• kjølerøret = the cooling pipe

The definite ending changes depending on the noun’s gender.

Yes. This is standard Norwegian declarative word order:

Subject + verb + adverbial/place phrase

So:

• Kjølerøret = subject
• ligger = verb
• bak innedelen = place phrase

This is the normal pattern for a simple statement.

You would normally say:

Et kjølerør ligger bak innedelen.

Here the noun is indefinite:

• et kjølerør = a cooling pipe

Compare:

• Kjølerøret ligger bak innedelen. = The cooling pipe is behind the indoor unit.
• Et kjølerør ligger bak innedelen. = A cooling pipe is behind the indoor unit.

The letter ø is a vowel that does not exist in standard English. It is pronounced with rounded lips. English speakers often find it tricky at first.

A rough guide:

• kjø starts with a soft ky-like sound
• ø is somewhat similar to the vowel in French deux or German schön, if you know those

Also:

• kj in many dialects is pronounced like a soft h-y / sh-like sound, though this varies
• røret has two ø sounds

The best approach is to listen and imitate native audio, since spelling alone does not fully show the sound.

Yes, Kjølerøret er bak innedelen is understandable and grammatically possible, but ligger is usually more natural when talking about the physical position of an object.

So:

• er = more neutral, simply states identity/location
• ligger = more idiomatic for an object resting or being situated somewhere

In technical or everyday Norwegian, ligger bak innedelen sounds very natural.