Are we targeting ASHP's at the wrong market?

[JamesPa]

38 minutes ago, Beelbeebub said:

Technically speaking the heat in an A2A heatpump is delivered as a hot gas (vapour) that is condensed into a liquid at the point of heat delivery (the room unit heat exchanger coil). 

 

So it is a tricky question if the delivery is via gas or liquid. 

 

I'm not sure the legal system is capable of dealing with the finer points of thermodynamics 

 

 

Thanks for the clarification.  I think you are right that the legal system can't deal with the finer points of thermodynamics but on that account I would say the delivery medium is a gas.

 

It would be interesting to understand what the intent was.  If it's only to allow a2W why use 'liquid' as opposed to 'water ( which may be treated to prevent corrosion or freezing)'

[Beelbeebub]

I've poked around to try and see where the prohibition on A2A might be. 

 

I haven't found it yet, except that the new system must provide all the heating and hot water and no hybrid systems are allowed. 

 

There are very few A2A systems that can also provide hot water. I believe daikin do one, but I haven't actually seen it in this country and I don't think it has any mcs certification. 

 

So maybe it would be as simple as allowing hybrid systems. 

 

Again, I think allowing A2A would see a significant up tick in installs as it would be cheaper and hence might be entirely covered by the grant. It is also potentially less disruptive for some properties. 

 

There would be an issue with skills as we don't traditionally have many A2A fitters in the UK. 

 

That said, if we coukd get our arses into gear around r290 and the manufacturers could produce r290 multi splits, I don't expect there would be much conversion from a gas safe engineer to an r290 safe engineer. There aren't any actual skill sets that are different the main criterion is being responsible and diligent when it comes to ensuring the gas lines are secure. 

 

 

[JamesPa]

7 minutes ago, Beelbeebub said:

I've poked around to try and see where the prohibition on A2A might be. 

 

I haven't found it yet, except that the new system must provide all the heating and hot water and no hybrid systems are allowed. 

 

There are very few A2A systems that can also provide hot water. I believe daikin do one, but I haven't actually seen it in this country and I don't think it has any mcs certification. 

 

So maybe it would be as simple as allowing hybrid systems. 

 

 

 

 

Here are the regs for BUS

https://www.legislation.gov.uk/uksi/2022/565/contents/made

 

Reg 9(2) requires that the heat is delivered by a liquid.

 

Based on your explanation of A2A above I think that excludes A2W but there clearly may be room for debate.

 

Definitely there is no exclusion of units capable of cooling as some maintain there is.  However pd rules don't apply if used for cooling, which is a separate consideration to the grant.