Hello,

One of my clients requests to know if the MVL 661.20-2.5 is compatible with refrigerant R449a. They are doing a retrofit from an installation that had the MVL and aRWR 62.732 controller. The refrigerant wasR404a and they want to change it to R449a.

In the documentation from HIT I have found details concerning R410, R404, R401... but no R449a.

There is no R32 either in the documentation. I believe it would be better to update it to take into account all the new refrigerants that are being used nowadays.

Can you please help me with this? I did not find any information on the RWR controller either. Where could I find it?

Thank you in advance,

Antonio

Hello antonio;

Products from Siemens Building Technologies are not easily accessible outside of that division, and information is not easily gathered from our side (Siemens Industry- Automation and Drives).

The standard datasheet for the MVL661.20-2.5 refrigerant valves only mention the same refrigerants that you show in your post. There is no mention of R449a.

https://www.downloads.siemens.com/download-center/Download.aspx?pos=download&fct=getasset&id1=10473

I can only suggest that you continue this search with SBT personnel, using their Contact meassaging address: www.siemens.com/bt/contact

This can be found on the support webpage for SBT, where you can find further ressources.

https://www.buildingtechnologies.siemens.com/bt/global/en/support/Pages/support.aspx?opentbb=1

Hope this helps,

Daniel Chartier

Thank you Daniel for your answer. The resources are indeed useful for the future. 

Unfortunately the answer to my question is not there, so I guess I will keep looking somewhere else.

Hello antoni;

Have you tried reaching out to SBT personnel through the contact link suggested above? They should be the most competent support.

Hope this helps,

Daniel Chartier

Dear Antonio,

The MVL661.. valve is compatible with R449a refrigerant.

Please note that the customer has to check if the size/DN of the existing valve is still matching in case of retrofit. Depending on the pressures / temperatures in the circuit, the kvs for R449a is about 25% smaller than for R404a. This means the installed valve should be big enough, but not the whole mechanical stroke range can be used in future for controlling (100% of the capacity will be reached with a smaller stroke).

Best regards,

Albis

Thank you Albis, this is what I was looking for. Are you based in Zug? 

Antonio