Why aren't A2A ASHP more popular

[markocosic]

Also FYI:

 

https://www.auer.fr/en/products/heat-pump-water-heaters/

 

Place air sourced ones in bathroom to dehumidify bathroom air and extract heat. 

 

Water sourced ones nick heat from UFH return.

 

 

 

[Iceverge]

1 hour ago, puntloos said:

UVC? A google search says Ultraviolet - to clean air, desinfect?

Unvented cylinder. 

 

1 hour ago, puntloos said:

This one is heating only though. Did you intend that?

 

 

No that was an accident. Didn't know that about split heat pumps re efficiency. 

[puntloos]

An update to my thinking:

 

Water FCUs are pretty lossy- you'd have to convert air to coolant to water to air. Also, because the temperature of the water going through a water FCU is low, the unit is less effective. 

Coolant (R32) FCUs can be more effective and therefore probably quieter. 

 

As such, I think I would currently pick two separate devices

 

A2A Multi-Split ASHP with ideally one FCU per major room. 

Small A2W Split ASHP, probably from the same brand so the same team can install them. Drives hot water and UFH

 

I know it's doubling up on the devices but ha, some high capacity ASHPs have two fans anyway, so having two 1-fan devices almost doesn't make a difference, same trench for dual coolant lines etc etc. Hopefully this will not be *too* bad an additional cost in the greater scheme of things.

 

My big question: if a concealed ceiling FCU is "200mm", would it fit in a 240mm ceiling? You'd think, but for example this brochure:

https://www.daikin.co.uk/en_gb/products/fdxm-f9.html - says the device is 200mm high, but also "Compact dimensions, can easily be mounted in a ceiling void of only 240mm" 

 

What gives? How much void do I need? (my current design is 210mm)