Any fridgies here? Heat pump brand choice...

[Haakon]

Am down to Fujitsu and Mits Heav Ind for a 10kw ducted system. Fujitsu is a bit cheaper and bit more efficient on paper - any reason to not choose over the Mits?

Samsung is waaaay cheaper than either but reviews are not promising for reliability.

All are R32 systems, and as I'll be fitting ill be winging it on warranty so reliability is key!

 

[slowmick]

Compare the low temperature heating performance - see which one will handle the cold climate better.
Please get someone to install it. R32 goes bang.

 

[Haakon]

Compare the low temperature heating performance - see which one will handle the cold climate better.
Please get someone to install it. R32 goes bang.

Min operating temp for heating is -15 for the Fujitsu, -20 for the others. Not even here does it get that cold!

R32 isn't that bangy - better than the butane/propane bland I charge the car AC with And better than petrol...

 

[slowmick]

The brochure may have a H2 (2°C Ambient) heating capacity on it. The standard temperature for the heating capacity is 7ºC DB, 6ºC WB. The H2 figure gives you an indication of how the capacity drops off at lower temperatures.

 

[Haakon]

The brochure may have a H2 (2°C Ambient) heating capacity on it. The standard temperature for the heating capacity is 7ºC DB, 6ºC WB. The H2 figure gives you an indication of how the capacity drops off at lower temperatures.

Dont appear to...

Fujitsu SET-ARTH36KHTA 10.0kW High Static Ducted Air Conditioner 1 Phase

Fujitsu SET-ARTH36KHTA 10.0kW High Static Ducted Air Conditioner System 1 Phase 10.0kW Cooling Capacity | 11.2kW Heating Capacity

www.airconditioning-online.com.au

Mitsubishi Heavy Industries FDUA100AVNAWVH 10.0kW High Static Ducted System | 1 Phase

Mitsubishi Heavy Industries FDUA100AVNAWVH 10.0kW Ducted System | Single Phase | R32 Refrigerant | 30m Precharged and 50m max pipe length

www.airconditioning-online.com.au

 

[ausdb]

Both are good products, a lot of times reliability comes down to the installation and with ducted system overall operation is as much duct design, airflow and circulation than the brand of the unit.
As @slowmick has pointed out low ambient heating performance is a priority. Be careful with MHI there are two outdoor units available for the same indoor. The one you have linked has better low ambient performance than the FDC100VNP-W outdoor which is cheaper.
As suggested please do get a licensed person to install it, ideally a full RAC license holder. A/Cs are expensive to fix if they break down and manufactures will not support you when it breaks if you choose to diy. Also if your house does burn to the ground by accident because of your installation, you won't be self insuring yourself for the loss. Cheap insurance really.
PS if you do DIY please make sure to post pics of your handiwork online for all to enjoy, those on crappy refrigeration on fakebook would especially love it. ARC also recently got a successful prosecution based on an unlicensed persons social media post.

 

[Fred Nurk]

Relatively recent feedback I've got is that FuShitsu is not what it used to be. Used to be a great brand (our original house ACs were all Fujitsu) but more recent equipment does not have the same reliability.

 

[Haakon]

Both are good products, a lot of times reliability comes down to the installation and with ducted system overall operation is as much duct design, airflow and circulation than the brand of the unit.
As @slowmick has pointed out low ambient heating performance is a priority. Be careful with MHI there are two outdoor units available for the same indoor. The one you have linked has better low ambient performance than the FDC100VNP-W outdoor which is cheaper.
As suggested please do get a licensed person to install it, ideally a full RAC license holder. A/Cs are expensive to fix if they break down and manufactures will not support you when it breaks if you choose to diy. Also if your house does burn to the ground by accident because of your installation, you won't be self insuring yourself for the loss. Cheap insurance really.
PS if you do DIY please make sure to post pics of your handiwork online for all to enjoy, those on crappy refrigeration on fakebook would especially love it. ARC also recently got a successful prosecution based on an unlicensed persons social media post.

Cheers.
Im not a complete numpty, an electrician will do the power supply - I need the whole fuse board replaced and a new power supply run for the heat pump - the existing pump is only 6kw and the 15 amp supply won’t cut it for the new one. Plus there is some “inventive” wiring currently there that needs sorting out… As for the charge, I can flare pipes and have gauges and a vacuum pump and know how to evacuate and test etc.

 

[Haakon]

Both are good products, a lot of times reliability comes down to the installation and with ducted system overall operation is as much duct design, airflow and circulation than the brand of the unit.
As @slowmick has pointed out low ambient heating performance is a priority. Be careful with MHI there are two outdoor units available for the same indoor. The one you have linked has better low ambient performance than the FDC100VNP-W outdoor which is cheaper.
As suggested please do get a licensed person to install it, ideally a full RAC license holder. A/Cs are expensive to fix if they break down and manufactures will not support you when it breaks if you choose to diy. Also if your house does burn to the ground by accident because of your installation, you won't be self insuring yourself for the loss. Cheap insurance really.
PS if you do DIY please make sure to post pics of your handiwork online for all to enjoy, those on crappy refrigeration on fakebook would especially love it. ARC also recently got a successful prosecution based on an unlicensed persons social media post.

Also that Facebook group is great - so many great ideas!

 

[fatboyonabike]

how did you get on Harkers?...keen to see which way you went and why

 

[Haakon]

how did you get on Harkers?...keen to see which way you went and why

Bought the Mits Heavy Industries 11kw R32 one when I was on the mainland in the car a couple of months ago.

Sadly it’s not made it past being the two large boxes in the shed…

Did have a sparky come and replace the fuse board (upgrading the original 1968 one!) and upgrading it to a 32amp supply. Have a few other renovations tasks before I get to getting the internal unit hung. The sparky turned out to be a nice bloke who has the tickets and kit for doing ac gas and is willing to work with me should I need help flaring, fitting and leak testing, and will make the final electrical connections for me once I have the units set up, so that’s nice.

 

[Haakon]

As for the why, it was a very good price (around a grand cheaper than I could have got it here…), the seller was easy to work with and convenient (a super helpful and friendly wholesaler in Mount Waverley around the corner from the FIL where I stay when I’m in Melbourne) and it has very good efficiency specs.

From what I was able to tell, the brand is decent for reliability and support, although realistically I’m winging it on warranty.

 

[fatboyonabike]

32 amp for the whole house or just for the AC?

 

[Haakon]

32 amp for the whole house or just for the AC?

Just the AC. Worked out it’s pulling about 27amps when going flat out.

New external cutoff switch as well, upping that from 25 to 40 amp rating.

 

[Haakon]

Have to get the electricity company out to replace a meter loop too as that’s getting a bump in size. Mildly annoying that’s another $188 callout charge on top of a $1700 the sparky charged…

I’ve no idea if I could have gotten that cheaper, but this guy is a sensible non bogan and unlike the majority of tradies I’ve encountered down here actually showed up when he said he would and did a decent looking job.

 

[fatboyonabike]

nothing wrong with MHI, have installed a few...I rate them over Daikin and fushitsu...Hitachi are another good one if playing at home..
27amps is a beast...but you will never need to run it flat out will you?..thats on cooling though, and Tasmania!

 

[Haakon]

nothing wrong with MHI, have installed a few...I rate them over Daikin and fushitsu...Hitachi are another good one if playing at home..
27amps is a beast...but you will never need to run it flat out will you?..thats on cooling though, and Tasmania!

No, will likely never be run full bore on cooling - it’s going to be 80-90% a heater!

But I’m not wanting to be dodgy with the install and especially not with the power supply side.

 

[Haakon]

@fatboyonabike mind if I pick your brain on return air routing/design…?
Option A was in the wall on the hall and into the spare room with a plenum box made to transition into a hole in the floor - and to the air handler slung under the floor.

But with a new linen cupboard installed, am keen to mirror the setup we had in Canberra with the grill in the cupboard door and the return in the floor of the cupboard.

Catch is that this house is oddly designed and the floor under the cupboard is a cavity between the floor joists and ceiling joists of the downstairs stairwell. The cavity opens straight out into the shed though and a straight shot to the air handler.

The opening out into the shed would be 20x80cm if I line two of the joists, I can make a hole in the floor 25x70cm. Was thinking foil backed vapour barrier to seal it (after vacuuming out the rat shit…) which also gives it the fire rating. I think I can box it and seal it effectively.

Return plenum on the air handler is 35x90 and the max flow of the fan is 650l/s flat so, so likely not ever over 550-600. All the flow/size charts I can find suggest 20x80 gives about 600 L/s or around 1200cfm for the seppos…

I know panning joists is far from ideal, but really would be nice to have it in the cupboard and not have a plenum box sticking out into the spare room!

Dumb idea, or doable…?

 

[fatboyonabike]

if the numbers stack up, it should be fine...any narrower, you may have some velocity issues with rushing air noise, But unless Im missing something? ...can you adjust the airflow at each register to match the return air volume using a kestrel or similar?

 

[Haakon]

if the numbers stack up, it should be fine...any narrower, you may have some velocity issues with rushing air noise, But unless Im missing something? ...can you adjust the airflow at each register to match the return air volume using a kestrel or similar?

Thanks mate - just needed someone who know's what they're looking at professional to not be utterly horrified at the idea

One good thing about have great access to the system is that I can muck around with it later tuning/fixing any issues I find!