Luftutskiftingen og varmegjenvinningen kontrolleres samtidig.

Because both nouns are in the definite singular form.

In Norwegian, you often show the by adding it to the end of the noun:

• luftutskifting = air exchange

• luftutskiftingen = the air exchange

• varmegjenvinning = heat recovery
• varmegjenvinningen = the heat recovery

This is very common in Norwegian. Instead of a separate word like the, the noun usually gets a definite ending.

Because Norwegian usually puts definiteness on the noun itself.

So instead of saying something like the air exchange, Norwegian commonly says:

• luftutskiftingen

and instead of the heat recovery:

• varmegjenvinningen

This is one of the biggest differences from English. In many cases, the ending does the job that the does in English.

Yes. Norwegian forms compounds very freely, much like German.

For example:

• luft = air
• utskifting = replacement / exchange
  → luftutskifting = air exchange

And:

• varme = heat
• gjenvinning = recovery / recycling
  → varmegjenvinning = heat recovery

English often writes these as separate words, but Norwegian very often joins them into one word.

The ending -ing often makes a noun from a verb, similar to English -ing, -tion, or -ment, depending on context.

For example:

• å skifte ut = to replace / exchange

• utskifting = replacement / exchange

• å gjenvinne = to recover / reclaim
• gjenvinning = recovery / reclamation

So these are action/process nouns.

Kontrolleres is a passive form.

• kontrollerer = controls / is controlling
• kontrolleres = is controlled / are controlled

So the sentence uses the present passive:

• kontrolleres samtidig = are controlled simultaneously

This -s passive is very common in Norwegian, especially in technical, formal, and written language.

Yes. Both are possible, but they can sound slightly different in style.

• kontrolleres = present passive, often compact and formal
• blir kontrollert = also passive, often a bit more explicit and natural in some contexts

So this sentence could also be expressed as:

• Luftutskiftingen og varmegjenvinningen blir kontrollert samtidig.

In technical writing, kontrolleres is especially common.

Because Norwegian verbs do not change for person or number the way English sometimes does.

Compare:

• Den kontrolleres. = It is controlled.
• De kontrolleres. = They are controlled.

The verb form stays the same.

So even with two subjects joined by og, kontrolleres does not need a special plural form.

Og simply means and.

It joins the two subjects:

• luftutskiftingen
• varmegjenvinningen

Together they form a compound subject:

• Luftutskiftingen og varmegjenvinningen = the air exchange and the heat recovery

Samtidig means simultaneously, at the same time, or concurrently, depending on context.

Here it tells you how the controlling happens:

• kontrolleres samtidig = are controlled at the same time

It functions as an adverb.

That is a very natural place for an adverb like this in Norwegian.

The basic structure is:

• Subject + verb + adverb

So:

• Luftutskiftingen og varmegjenvinningen kontrolleres samtidig.

That sounds neutral and normal.

You can move samtidig for emphasis in some contexts, but the version here is straightforward and standard.

Yes. Very much so.

Several things make it sound technical or formal:

• long compound nouns
• definite forms
• passive verb (kontrolleres)
• concise wording
• adverb samtidig to describe process timing

This kind of structure is common in manuals, engineering texts, system descriptions, and official writing.

Partly, but not perfectly.

The ending -en is commonly used for masculine definite singular nouns, and many learners will recognize it that way. In practice, though, some nouns that are often treated as feminine can also appear with -en in Bokmål, because many feminine nouns allow a masculine-style form.

So for a learner, the most useful point here is:

• -en marks definite singular
• you should still learn each noun’s gender separately when possible

You would remove the definite endings:

• Luftutskifting og varmegjenvinning kontrolleres samtidig.

That sounds more general, like talking about the processes in principle rather than specific ones.

Compare:

• luftutskiftingen og varmegjenvinningen = the air exchange and the heat recovery
• luftutskifting og varmegjenvinning = air exchange and heat recovery

So the definite forms make the sentence sound more specific.

A practical learner-friendly approximation is:

• kon-tro-LE-res

A few helpful points:

• the ll is pronounced like a normal l
• the r is usually tapped or lightly rolled, depending on dialect
• the final -es is clearly pronounced, because it marks the passive form

You do not need perfect pronunciation right away, but it is useful to notice that the ending -es is not silent—it carries important grammar here.