Dimplex Air source Heat Pump

supastar42

Has anyone any experience of a Dimplex ASHP, particularly the 9kW unit, LA 9 MI?

They fit a buffer tank as standard to supply heat on the defrost cycle without taking heat from the heating circuit. Nobody else such as Mitsubishi and Samsung does this. Any comments?

StanBowles11

I've just had a Dimplex LA MI 12 fitted. I've got an old house that we're having an extension on. Previously we had storage heaters so I had to retrofit a wet radiator system plus I've also installed UFH in the new build part of the house and in part of the existing house where it was practical to excavate the floor and install decent floor insulation. We also upgraded all windows and doors which were previously single pane glazing with triple glazing. The heat pump has been in two weeks and we're really pleased with it. The house is toasty warm even though there is snow and very cold weather outside and our energy costs are down - early days so I will report on exactly how much later.

nande2000

supastar42 wrote: »

Has anyone any experience of a Dimplex ASHP, particularly the 9kW unit, LA 9 MI?

They fit a buffer tank as standard to supply heat on the defrost cycle without taking heat from the heating circuit. Nobody else such as Mitsubishi and Samsung does this. Any comments?

I know Mitsu Ecodans can be used with buffer tanks if you want (probably the Samsung too), but Mitsu say they arent required. I find the defrost cycle on my 8.5kw Ecodan is fairly infrequent and you dont notice heat loss from the house. Some will say that the real point of a buffer tank is to extend the lifetime of the compressor in the heat pump, but i have no idea if makes economical sense to do so.

supastar42

I have since read in the Samsung bumph that they do not need a buffer tank as long as there is a minimum of 20 litres in the system. They say the variable speed compressor means the unit can operate without a buffer.
It also appears that a larger than usual pressure vessel can be fitted to give a larger system capacity.

Silent_Dancer

supastar42 wrote: »

I have since read in the Samsung bumph that they do not need a buffer tank as long as there is a minimum of 20 litres in the system. They say the variable speed compressor means the unit can operate without a buffer.
It also appears that a larger than usual pressure vessel can be fitted to give a larger system capacity.

Do not install a heat pump without a buffer vessel, your running costs will be increased due to short cycling no matter what technology there is in the compressor.