I failed to say that the design allows for a 50C flow temperature but since the engineer did some fettling I have not investigated it again.

Posted by: @timatheronwood

↑

I failed to say that the design allows for a 50C flow temperature but since the engineer did some fettling I have not investigated it again.

Oh, you can't beat a good 'fettle'. 😋 

I had the unit set to 18 overnight (till 4am) and 19 from then on but this morning at 6am the temperature in the house was down to 17.5C It had not risen beyond that by 10am. At 12 noon the temperature had risen to 18C in the house. I have changed the slope of the "curve" so that it now reaches maximum at 0C instead of -10C. This afternoon the temperature had risen to 18.5C and I have changed the temperatures to 20C in the day and 19 at night to cope with the cold weather. 

Could this be due to the unit not meeting the design spec for output temperature. The Daikin literature says that we should be able to get a 65C output. But the most I have ever seen is 45C even thought it is set to 63C. 

Any thoughts anyone?

@rod 

Perhaps I should add to the above system (sorry, but I failed to be able to edit the entry) based on a Daikin 8 kW ASHP that the domestic hot water heating is handled by a Sunamp Thermino ePV210 heat battery. The reason being, space is at a premium and the MCS guideline for a 4 bedroom house is 210 litres of DHW storage and we just do not have a space for such a tank! The Thermino is considerably smaller and can be accommodated (just!) in our airing cupboard - the insulation is extremely good so the total heat loss in 24 hours is less than 0.75 kW/h, so very little warming is available in the airing cupboard - just the lost heat coming from the unlagged plumbing from the LLH etc. and this helps to provide a background warmth in the cupboard.

I scored 10 myself for insulation as we have double glazing (triple in one room), cavity wall insulation, underfloor insulation from Q-Bot on the ground floor and approx. 40 cm. of loft insulation plus boarding sandwiched in the middle, plus we have approx. 5 cm. thick insulating board with a foil face between all the roof truce work just below the roofing felt. Our EPC rating before installing the Solar PV, battery and then the ASHP was a ‘B’ with notes indicating that Solar PV and / or Heat Pump would improve the rating.

I hope to incorporate an Evergreen Homely smart thermostat system for ASHP control as soon as a compatible device for the Daikin is available. Perhaps I should also mention that the Power Diverter is the Myenergi Eddi with a Harvi and several CT Clamps. We are using the Octopus Energy Agile and Agile Outgoing tariffs for import and export (no James Bond involvement however). 😉 Regards, Toodles

If Homeowners are prepared to provide the information, then maybe a spreadsheet containing the following information would be of most use from the comparison, and highlighting of possible problems, point of view.

Forum Handle: @FJJ

Manufacturer: Grant

Model: HPID10R32

Type: ASHP

Arrangement: Mono

Area of Country: Warwickshire

Home Type: 3 bed detached 1970's

Size: Square Metres: 100

Insulation Level: Scale of 1 to 10 possibly? 7

Heat Loss Calculation: kW @ Amb. Temp, of: -1.1C 6.8 kW

Type of Controller: Modulating

Type of Control: Weather Compensation

System Type: Radiators (5K3, 3K2, 1K1 Stelrad compact)

Total Output of Heat Emitters: not known 

Buffer Tank or Low Loss Header: LLH

Secondary Pumps: Number  1

Solar PV System: Size or No 8 kW

Power Diverter: Yes

Battery System: Size; 10Kw Solaredge Powerbank

Forum Handle: MikeFl

Manufacturer: Grant

Model: Aerona HPID10R32

Type: ASHP

Arrangement: Mono 

Area of Country: Cumbria

Home Type: Dormer Bungalow

Size: Square Metres: 148

Insulation Level: 7? (Loft/eaves insulation topped up with 30mm+; Room in Roof insulation is less

Heat Loss Calculation: 9-10kW @ Amb. Temp, of: 10C (this is my calculation - hope the installer has a better one)

Type of Controller: Two zones (up/down) controlled by room thermostats, with TRVs on all but two radiators

Type of Control: Fixed flow temperate at installation, possibly.

System Type: Radiators

Total Output of Heat Emitters: K2 *3, K3 * 4, K1 * 1

Buffer Tank or Low Loss Header: Grant volumiser / LLH

Secondary Pumps: 1(Grundfos ups3 15-50)

Solar PV System: No

Power Diverter: No

Battery System: No

Water cylinder is a FlowCyl Slimline 170L (FCHPS2170) with 24kW heating coil installed. 

Forum Handle: Madrajin

Manufacturer: Vaillant

Model: Arotherm Plus 7kw, UniTower plus, sensoComfort

Type: ASHP

Arrangement: Monoblock, high temp I think.

Area of Country: General Location

Home Type: House solid wall construction, built 1763 (uniTower located in outhouse)

Size: Square Metres: 126m2

Insulation Level: Scale of 1 to 10 possibly? Listed as energy mark D when I bought it

Heat Loss Calculation: kW @ Amb. Temp, of: ?C

Type of Controller: unknown (sensoComfort), EveThermo TRV

Type of Control: Adaptive, Weather Compensation, Flow Temperature, Room Temperature

System Type: Radiators unchanged, mostly double.

Total Output of Heat Emitters: ? kW

Buffer Tank or Low Loss Header: No

Secondary Pumps: No

Solar PV System: No

Power Diverter: No

Battery System: No

Forum Handle:  GC61

Manufacturer: Viessmann

Model: Vitocal 151-A

Type: ASHP

Arrangement: Mono

Area of Country: Ireland

Home Type: 2-Storey detached

Size: 180 sqm

Insulation Level: 8

Heat Loss Calculation: 1.63

Type of Controller: Viessmann Vitotrol 300-E

Type of Control: Weather Compensation / Flow Temperature / Room Temperature

System Type: UFH and radiators

Total Output of Heat Emitters: 

Buffer Tank or Low Loss Header: 

Secondary Pumps: 

Solar PV System: 4.2KW

Power Diverter: No

Battery System: No

Forum Handle: @dougmlancs

Manufacturer: Panasonic

Model: Aquarea L (R290)

Type: ASHP 

Arrangement: Split with hydraulic connection

Area of Country: Lancashire

Home Type: Semi-detached house

Size: Square Metres: 110

Insulation Level: CWI, DG + 300mm loft

Heat Loss Calculation: 7.1kW @ Amb. Temp, of: -3C

Type of Controller: Modulating, no 3rd party thermostats, TRV’s set in bedrooms otherwise all open full

Type of Control: Weather Compensation

System Type: Radiators

Buffer Tank or Low Loss Header: No

Secondary Pumps: No

Solar PV System: 4.44 kW

Power Diverter: No

Battery System: 9.5kWh Givenergy battery

Forum Handle: @ajdunlop

Manufacturer: Mitsubishi 

Model: Ecodan R32 8.5kW (PUZ-WM85VAA)

Type: ASHP

Arrangement: Mono

Area of Country: West Yorkshire, England

Home Type: End Terrace House

Size: Square Metres: 170m2

Insulation Level: 6/10 (Attic very well insulated, some main rooms with IWI, others not insulated yet and suspended floors not insulated yet)

Heat Loss Calculation: 7.54kW @ Amb. Temp, of: -2C (Self calculated using Heat Engineer)

Type of Controller: Ecodan FTC6 Main controller in Hallway, Smart TRVs on most Rads (set to limit overheating)

Type of Control: For 1st winter probably a mix of Weather Compensation and use of Ecodan's Auto Adaptive taking room temperature from main controller

System Type: Radiators (mix of very old P1, less old P2 and some newer K2)

Total Output of Heat Emitters: 9.863kW (@45C flow temp)

Buffer Tank or Low Loss Header: No

Secondary Pumps: No

Solar PV System: 4.4 kW (12x JA Solar 370W Panels evenly E-W Split, Inverter Fox ESS Hybrid H1-3.7-E)

Power Diverter: Yes (Soon to be installed Eddi, hopefully wired to use immersion at low overproduction and the ASHP for high overproduction)

Battery System: 5.8 kW (Fox ESS Cube CM2900 + CS2900)

Forum Handle: Crustydoodle

Manufacturer: Mitsubishi

Model: Ecodan R32 11.2kW

Type: ASHP 

Arrangement: Mono

Area of Country: South East

Home Type: Detached House

Size: Square Metres: ~190

Insulation Level: Scale of 1 to 10 possibly? High

Heat Loss Calculation: 9.7 kW @ Amb. Temp, of: -2.39C

Type of Controller: FTC6 + Neomiser Thermostats in every room (11 zones)

Type of Control: Room temp I think; HW set to 50DegC and reheats when 10 below

System Type: UFH.

Total Output of Heat Emitters: Unsure - something says 19kW heat demand

Buffer Tank or Low Loss Header: None

Secondary Pumps: Not sure

Solar PV System: No

Power Diverter: No

Battery System: No