NIBE or Mitsubishi ASHP?

[JamesP]

I have a couple of quotes to consider for our DHW / Heating solution. UFH and ST for both.

 

1. NIBE F2040-12 with 100 litre buffer and 500L UVC

2. Mitsubishi Ecodan W85 with 300L UVC, no buffer.

 

Have read @Stones excellent blog about Ecodan.

Can anyone share any other experiences of the above topic,

Thanks all.

[PeterW]

Do you need a 12kw ASHP ...?? What’s the heat loss for the building ...?

[ragg987]

Have no experience of either, however do check that you have someone locally who can service the one you choose. I went with a hitachi and am struggling with that aspect - and the 5 year warranty is useless without a service.

[JamesP]

2 hours ago, PeterW said:

Do you need a 12kw ASHP ...?? What’s the heat loss for the building ...?

The heat loss is 11248 for heating and 4921 for HW. Total 16169kWh. 

Both suppliers had the SAP test.  Over specification? 

@ragg987 Good point.

[A_L]

1 hour ago, JamesP said:

The heat loss is 11248 for heating and 4921 for HW. Total 16169kWh. 

Both suppliers had the SAP test.  Over specification?

 

I am assuming 220m² floor area, 0.11-0.15 fabric U-values, T shaped bungalow with cathedral ceilings (from blog), 5kW (maybe even 4kW) for instantaneous heatloss plus perhaps 2kW for DHW (worst case). So as suggested by quote for 8.5kW Ecodan 12kW NIBE oversized.

[Alexphd1]

Both heat pumps have very good reputations. Probably I would side with the ecodan simply because I see more of them in the AC world and better chance to find a engineer with experience on the gas side. 

[JamesP]

Thanks @A_L and @Alexphd1.

Correct on the internal floor area. Have a lot of insulation, 3G windows and doors and MVHR. Its airtight.

Just want to run a system which is efficient for a family of 4 for 90% of the time. 

Can someone tell me what a scroll vs inverter ashp is?

 

[Alexphd1]

Scroll compressor v inverter that's above me tbh. But I thought they where the same thing but the inverter part is the compressor just changing speed for varied output demand. Somebody will be along with the exact answer.

[PeterW]

Scroll compressors are pretty heavy duty, inverter is how they power them and you can have an inverter scroll compressor .... 

[Jeremy Harris]

There are loads of Mitsubishi air con units around, which are pretty much identical internally to an ASHP (strictly speaking they are the same thing) so I suspect that maintenance and repair for the Ecodan, should it ever need it, may well be easier than finding someone with experience of working with NIBE kit.  NIBE kit is well made, though, so should be as reliable I'd have thought.

 

As above the heating requirement seems very high for a well-insulated and sealed house.  Our place is 130m² and needs an absolute maximum in very cold weather of around 1.5 kW for space heating and it's very rare for it to need more than a few hundred Watts.  I'd have thought that a place that's around 1.7 times the size shouldn't really need more than around 2.5 to 5 kW for space heating, most probably a lot less most of the time.  Hot water is the challenge, and is where most of the heat energy will be needed in practice, I suspect.