Split unit/ F-Gas ongoing costs, compared to G3 servicing?

[joth]

Slightly strangely formed question, what are the ongoing F-Gas  service & maintenance costs and "hassle factor" for a typical split-system ASHP,  compared to the G3 service & maintenance costs for an unvented cylinder?  

 

Reason I ask is it seems if I want ASHP to provide 100% of DHW and space heating and cooling needs I have two options:

- Monobloc LT ASHP (55ºC max) with UVC (=> G3 service)

- Split system LT ASHP (65ºC max)  with SunAmp PCM58 (=> F-Gas service)

 

I'd been keen to avoid the split system to avoid the added F-Gas overheads, but maybe the G3 savings (both financial and hassle-factor) sufficiently offset it.

 

Notes:

The goal here is 100% DHW from the heat pump so  I'm also ignoring resistive DHW heating element for this comparison.

For the purpose of comparison, I'm ignoring any short cuts around DIY or ignoring the service schedule.

I'm ruling out HT monobloc ASHP as none seem to support cooling.

I'm assuming the 65ºC from a Daikin Altherma 3 (for example) is sufficient to activate PCM58.

If the refrigerant makes a difference, let's assume R-32 (again per the Daikin split units)

 

[DenkiJidousha]

I think the Daikin Altherma 3 should be OK with SunAmp UniQ PCM58 based on this:

https://twitter.com/eLEJOG/status/1192735318543339522

 

Can you wait 6 months? SunAmp seem confident about having lower phase-change heat batteries on sale then, but also I gather there will be newer monoblocks on the market soon with the next refrigerant gas. I'm tempted to wait and live with our gas boiler for one more winter...

 

[Dan F]

There are already R32 monoblocs that can provide 65C. Sunamp are currently testing one and are supposed to officially support it next month.

[joth]

@Dan Feist thanks again!

I saw the thread you were on too, but the statement here was only R32 LT with PCM43, didn't confirm monobloc or with PCM58. Is there more news since this?

I can't find evidence Daikin R32 monobloc yet? And Samsung's is still in trials. 

Are there any R32 LT monoblocs that support cooling too?  The LG doesn't seem to.

Early adopter squared!

 

 

Edited November 26, 2019 by joth

[Dan F]

The LG R32 Monbloc does support cooling.  It hasn't been validated by Sunamp though. Suamp are testing another manufactuer who has released (or is about to release) a R32 LT Monobloc.  They last told me in was panasonic and not samsung, so not sure..

 

In theory they are testing PCM43 and PCM49 currently.  These seem more interesting than trying to find an ASHP that heats to 65C and then hoping it works well with Sunamp and can still deliver 65C in the middle of winter when incoming water is cold and ambient temperature is low.  PCM49 would also give same COP's as you get heating to 55C for UVC while saving the cost of direct electricity needed (if i understand correctly) to regaularly heat the UVC to a higher temperature to avoid Legionella.

 

[Barney12]

18 minutes ago, Dan Feist said:

In theory they are testing PCM43 and PCM49 currently

Is there any more information on this? That’s two posts now ( @DenkiJidousha suggested 6 months away) that suggest Sunamp are testing lower temp phase change materials. 

[joth]

8 minutes ago, Dan Feist said:

The LG R32 Monbloc does support cooling

Thanks - I just found this too. I'll blame trying to read datasheets on a small screen too early in the morning.

Interesting Sunamp aren't testing (or have already tested and failed?) the LG, given it appears to be the most widely available R32 monobloc at this point. I was looking at Panasonic before, but there aren't a whole lot of suppliers/installers for them about (my area, at least)

 

PCM49 might work, but PCM43 seems to low to be useful on its own for DHW.  Not sure I would worry too much about the ASHP failing to charge the SA it in the very depths of winter, so long as it has a good 3kW immersion backup. It's being reliable the majority of the time. 

The LG says it can achieve 65°C water temp down to -2°C OAT,. however below 7°C OAT it will risk non-continuous operation (defrost cycle) if outputting anything over 55°C which indeed is where the real hit on COP begins.

 

 

9 minutes ago, Barney12 said:

Is there any more information on this? That’s two posts now ( @DenkiJidousha suggested 6 months away) that suggest Sunamp are testing lower temp phase change materials. 

 

See the tweet I linked above (from the founder of sunamp AIUI) -- that's about '43 only though.

 

[Barney12]

45 minutes ago, joth said:

See the tweet I linked above (from the founder of sunamp AIUI) -- that's about '43 only though.

 

Thanks. Sorry, completely missed that! 

 

So certainly not on general release. I wonder how they select "household tests"?

 

Based on previous Sunamp reliability perhaps they've learnt a lesson about putting units on general sale too quickly? I assume they put these units in FOC to get "real world" testing?

 

Edited November 26, 2019 by Barney12

[joth]

10 minutes ago, Barney12 said:

 

Thanks. Sorry, completely missed that! 

 

So certainly not on general release. I wonder how they select "household tests"? Based on previous Sunamp reliability perhaps they've learnt a lesson about putting units on general sale too quickly?

 

 

No worries! It's fairly light on detail, and as I said already sounds stale.

 

My hope is they plan  their testing over the Winter (when both DHW and ASHP work their hardest) in order to report back early in the new year. Being based in The North they should have access to some good quality Winter to test in.

Overall I think I'm in very similar situation to @Dan Feist - mentally committed to UVC but have a small window of opportunity (until March, maybe) to change that decision if something magic appears

 

 

 

 

[Dan F]

1 hour ago, joth said:

Overall I think I'm in very similar situation to @Dan Feist - mentally committed to UVC but have a small window of opportunity (until March, maybe) to change that decision if something magic appears

 

We do a a few months longer, as foundation will only be going in early March, but yes similair situation.  I was committed to the idea of Sunamp initially, but M&E guy talked me out of it, and the lack of tested LT monoblocs didn't help, so our spec now contains UVC.  If there is a PCM49 available prior to installation that i'd be very keen to switch to Sunamp though.

 

2 hours ago, Barney12 said:

Is there any more information on this? That’s two posts now ( @DenkiJidousha suggested 6 months away) that suggest Sunamp are testing lower temp phase change materials. 

 

My info was from conversation with Sunamp rep 7-10 days ago.

[Triassic]

On 26/11/2019 at 10:08, Barney12 said:

wonder how they select "household tests"?

In the past they used employees homes.