DIY Fitting of used ashp for cooling and heating.

[Simon Brooke]

After two years of living in our new self build we are generally very happy with our passiveish house. We have an underfloor system fitted but not really operational as the Sunamp is not man enough ( though does provide our hot water very well). We would like an ashp but only need input for a month or so and therefore reluctant to spend big money. I am now considering  a second hand ashp and would really like it to be reversible so that we can cool as well as heat the slab. Getting information from dealers or manufacturers as to which model would be suitable is proving difficult. I do have access to a five year old Daikin EDHQ014 B6V3 but the online manual indicates that cooling is an option but not applicable to all models? Does anyone have a recommendation for a model / manufacturer  which would easily switch from heating to cooling? Also is it sensible to think of a five year old model or should I stick to new?

Any advice gratefully received.

[JohnMo]

I think MCS sort of kills the option for cooling in the UK without modification.

 

If you only need a small amount of heat why not keep the money in you pocket and just go Willis heating.  But no cooling or something like a Dream heat pump from Ebay for second hand money, they do heat and cooling

[Nick Laslett]

I don’t believe that MCS prevents you from using ASHP cooling in England. @joth discussed this a few times. 
 

There appear to be some aspects that make it a little more challenging. 

[joth]

On 18/06/2022 at 09:02, Nick Laslett said:

I don’t believe that MCS prevents you from using ASHP cooling in England. @joth discussed this a few times

 

Correct, MCS (the scheme) does not and has never had any restrictions on cooling, it was RHI that had that constraint but it was lifted several years before RHI was withdrawn completely.

 

OTOH finding an MCS installer familiar and competent with installing a system for cooling can be tricky. My experience was I had to oversee most of the cooling aspects myself:

- ensuring all pipes and equipment properly insulated against condensation (and put right when they got it wrong)

- purchasing and planning ducting for the FCU install

- specifying a buffer tank sized for the FCU rather than assume UFH is always in use

- insisting on an electronic rather than thermostatic mixing valve for the UFH circuit

 

Installers don't do this often, and I don't know if MCS sets any standards related to it, hence the lack of experience in many installers