Heatpumps - environment vs wallet

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Paul1977

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#255487 14-Aug-2019 10:43

Will be putting ducted heatpump in new house and am trying to decide between Mitsubishi and Daiken.

For the appropriately sized unit Daiken is cheaper, but uses R410A refrigerant.

The Mitsubishi unit uses R32 refrigerant, which apparently has 3 times lower GWP (global warming potential) compared to R410A.

I’m generally not much of a greenie, but this seems like a big difference - or is GWP not a meaningful rating to base a decision on?

It’s a personal thing, but how much fo other geekzoners factor the environment into these sorts of decisions? And how much more are you willing to pay for the more environmentally friendly option?

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timmmay

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#2299055 14-Aug-2019 11:11

I would put more emphasis on performance. The refrigerant tends to be collected during decommissioning, unless it fails or slowly leaks out.

wellygary

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#2299075 14-Aug-2019 11:21

R410a is a 50/50 mix of R32 and R125, The R125 is the real nasty part

But as mentioned above, unless you develop a leak (which is rare) the refrigerant is captive and collected when they unit is decommissioned.

nunz

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#2300354 16-Aug-2019 11:28

1 - We had leaks (twice) in the newly installed heatpump. The installers made a real hash of the job - it did leak - twice. Also drip trays overflow when drain pipes are installed in an uphill direction. The drain pipe issue also happened in the previous install at the old house -so we have now seen 2 / 2 bollocks installs. I've also seen some real cowboys dealing with re-gassing or degassing units.

2 - Environmentally friendly - so subjective. If power is solar then there is environmental issues with solar panels - they aren't clean and green, to make or dispose of.

If power is coal / nuclear etc driven - then that's not environmentally friendly.

Outside pump units are noisy. Lots of wild life / insects don't like them and in our neighborhood (mostly heatpump) its noisy.

Modern ULEB fires are carbon neutral (I reckon carbon negative as growing trees use / sequester more carbon than older trees and the ash sequesters lots of carbon back into the ground).

The pre uleb low emission fires put out 1g of particulate per 1kg burnt. The new ULEBs are way more efficient. Ironically fires may be more eco friendly than Heat pumps - and that's not even taking into account e-waste, refrigerant, plastic, carbon miles as parts manufactured in lots of parts of the world, solder fumes, etc etc etc.

bfginger

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#2300561 16-Aug-2019 18:45

The EER/COP efficiency ratings (higher is better) and the annualised AEER/ACOP ratings reflect energy efficiency and are usually more important than whether the unit runs on R32 or R401A. New Zealand can't produce enough clean energy so any added to the pile isn't coming from hydro. Higher R ratings on the ducting can boost efficiency.

I personally would be wary of a ducted system. Installing them is a learned art few in New Zealand can manage. Energy efficiency of some ducted systems is not great and most outdoors units are too noisy (don't confuse pressure db with power db). Placement away from bedrooms and neighbours is important. Standby electricity use can be high which is indicated by the size of the gap between the AEER/ACOP and EER/COP ratings. So all round you need to understand and check the specifications carefully before committing to buy.

Multisplits are an alternative if you must have a single outdoor unit. The Daikin R32 multisplit would be what I'd go for if I was looking for one.

Multisplit and ducted lines aren't updated very often. The Mitsubishi R32 ducted are newer so specifications may be better more often than not.