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I'm considering upgrading my home heating to an air-to-air heat pump (AKA an air conditioner) as it makes a lot of sense, and everyone I know who has one loves it.

I wanted to get one that uses R290 (propane) as the refrigerant, due to its very low GWP (global warming potential, CO2 equivalent) value, which is now thought to be 0.02, down from an already very low 3.

But I can only find single-split units with R290, and I was hoping to buy a system with three indoor units.

All the multi-split systems I can find use R32 which has a GWP of over 650, clearly nowhere near as good as R290.

So is there something about R290 which makes it unsuitable for a multi-split system? Or are these systems just not on the market (here) yet?

I guess this would mean that my options are to just go with an R32 multi-split system, or buy three R290 single splits, or find some sort of R290 central air conditioning unit. (Or give up on the air-to-air, and buy a more expensive air-to-water R290 heat pump, using my existing hot water central heating radiators.)

I'm in the Netherlands, BTW.

isherwood
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JoLoCo
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1 Answers1

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R290 is non-odorized propane. It has no odor, which means that a leak will go unnoticed unless you run a propane detector 24/7.

This means that a R290 system has a legal charge limit based on various factors to prevent a single leak from filling a room with enough undetectable by your nose propane to be dangerous. In the EU this would be documented in IEC 60335-2-40.

A multi-split system needs a higher charge by their very nature of construction and moreover a leak in a multi-split system could dump the entire propane charge into a single room.

No manufacturer wants to have the liability of your gas explosion in the event of a leak.

So you'll have to make do with individual units which have been certified safe for the room they service.

edit: After doing some research the actual reason why the odor isn't added is because the odorant is not a stable substance it breaks down over time while corroding the metal inside the system. It also gets absorbed by the oil and filter medium. This means that the system's charge will stop smelling after a few days even when charged with cooking-grade propane. This makes it not useful for leak detection in a system designed to stay sealed for years.

ratchet freak
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