Author Topic: Heat Pump Hot Water System vs Gas Hot Water  (Read 31365 times)

0 Members and 1 Guest are viewing this topic.

Offline EEVblogTopic starter

  • Administrator
  • *****
  • Posts: 38039
  • Country: au
    • EEVblog
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #100 on: June 25, 2023, 01:59:21 pm »
Dave, did you disconnect your gas then, I still have a 5yo gas stove (do you have induction then) and so cant disconnect (making my decision more difficult because I cant get rid of the gas supply charge)?

Yes, disconected gas entirely.
We have always had an induction cooktop and stove.
BBQ was converted from natural gas back to LPG bottle.
 
The following users thanked this post: rthorntn

Offline Seekonk

  • Super Contributor
  • ***
  • Posts: 1940
  • Country: us
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #101 on: June 26, 2023, 05:37:18 pm »
"In saying that I'm pretty sure I have the excess solar to be able do this."

I'm sure Dave factored in paid views into his calculation.

I have a small off grid system and 60% of the panels are shaded at any one time. Yet, I still have enough excess power to supply domestic hot water and laundry has a dedicated hot water tank.  All cycles are done with hot water.  That sure eliminates mold buildup and stink of a front loader.  This is all done with resistance heating.  The trend is for export to pay almost nothing.  Efficiencies often don't matter with excess power.  My power point controller, which feeds directly off the PV panels, only cost about $20 to build and it uses existing tank. Just compare that to expenditure of a HPWH.  Finding a heating element which will fit into drain port of a gas water leaves you with only a few low power options. Adding an inline heating element and small circulating pump would be an interesting project. The economics still works for resistive heating unless lots of hot water is needed. Many people use less hot water than they think.
 
The following users thanked this post: rthorntn

Offline EEVblogTopic starter

  • Administrator
  • *****
  • Posts: 38039
  • Country: au
    • EEVblog
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #102 on: June 26, 2023, 11:00:09 pm »
"In saying that I'm pretty sure I have the excess solar to be able do this."
I'm sure Dave factored in paid views into his calculation.

Nope. That video made me $270, before tax.

3kWh/day is nothing, tons of excess.



« Last Edit: June 26, 2023, 11:05:46 pm by EEVblog »
 

Offline rthorntn

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: au
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #103 on: June 26, 2023, 11:08:34 pm »
Yeah, I have a 7.4kw system and now (middle of winter in Sydney) I have about 8kwh of excess on a sunny day, I also use 5kwh/day to run a pool pump.
« Last Edit: June 26, 2023, 11:10:05 pm by rthorntn »
 

Offline EEVblogTopic starter

  • Administrator
  • *****
  • Posts: 38039
  • Country: au
    • EEVblog
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #104 on: June 27, 2023, 01:17:19 am »
Yeah, I have a 7.4kw system and now (middle of winter in Sydney) I have about 8kwh of excess on a sunny day, I also use 5kwh/day to run a pool pump.

We have pool construction starting next week. Will be using a heat pump system for that too.
Is that 5kWh/day for the pool pump needed every day? or are you talking about heating?
#PoolNewbie
 

Offline rthorntn

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: au
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #105 on: June 27, 2023, 02:39:50 am »
Lol, I was going to suggest a PM to avoid taking the thread off on a tangent but its the guv'nor asking, we can still do that just let me know!

So I have a 60k litre pool, salt water generator, no heater, it came with the property, late last year I started using a pool cover.

I just put in a cheapy 1hp single speed pump, I would not do that again, I will go multi-speed next time (better power consumption). You'll be lucky to get 5 years from a cheapo pump so I'll probably be changing it soon.

I've had 20kwh of LTO batteries for a few years now and I'm on battery most of the year.  Only thing that I don't have on battery is my electric oven.

There is a bit of work to self maintaining a pool and its going to depend on how you use the pool, I've been self maintaining for a decade.

I close the pool for half the year, I run the pump for 4-6 hours in the swimming season with the chlorinator at 100%.  In the off season I run the pump for 4 hours at 70% chlorination.

Imho, you wont really need the heater in the summer, my water gets up to 31, shoulder months you will, winter would cost a fortune and I doubt you could get much of that off the solar.

If I had a pool heater and batteries then I would probably just wire the heater to the grid (unless I had over 10kwh of panels).  If I was to do it all again I might of started switching the pool off in the off season, let it go green and then shock it just before the swimming season starts.
« Last Edit: June 27, 2023, 03:01:05 am by rthorntn »
 
The following users thanked this post: EEVblog

Offline coppice

  • Super Contributor
  • ***
  • Posts: 8937
  • Country: gb
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #106 on: June 28, 2023, 03:13:43 pm »
Yeah, I have a 7.4kw system and now (middle of winter in Sydney) I have about 8kwh of excess on a sunny day, I also use 5kwh/day to run a pool pump.

We have pool construction starting next week. Will be using a heat pump system for that too.
Is that 5kWh/day for the pool pump needed every day? or are you talking about heating?
#PoolNewbie
Are you expecting to do most of that heating from solar power? Does the amount of sun and the need for heating line up well for that?
 
The following users thanked this post: rthorntn

Offline EEVblogTopic starter

  • Administrator
  • *****
  • Posts: 38039
  • Country: au
    • EEVblog
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #107 on: June 29, 2023, 06:09:37 am »
Yeah, I have a 7.4kw system and now (middle of winter in Sydney) I have about 8kwh of excess on a sunny day, I also use 5kwh/day to run a pool pump.

We have pool construction starting next week. Will be using a heat pump system for that too.
Is that 5kWh/day for the pool pump needed every day? or are you talking about heating?
#PoolNewbie
Are you expecting to do most of that heating from solar power? Does the amount of sun and the need for heating line up well for that?

It will need a battery solution to be most useful. At the monent we do still throw away a significant amount of excess solar energy.
 
The following users thanked this post: rthorntn

Offline kaz911

  • Super Contributor
  • ***
  • Posts: 1052
  • Country: gb
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #108 on: June 29, 2023, 10:59:05 am »


It will need a battery solution to be most useful. At the monent we do still throw away a significant amount of excess solar energy.

here is my almost finished "prepper" layout w 36.5 kWh of PylonTech batteries setup as ESS with Grid disconnect.

The Victron Cerbo GX controller now supports Node-Red directly - making custom actions really easy. 

I'm installing batteries right now.. :)

1815913-0
 
The following users thanked this post: rthorntn

Offline EEVblogTopic starter

  • Administrator
  • *****
  • Posts: 38039
  • Country: au
    • EEVblog
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #109 on: June 29, 2023, 11:04:02 am »
here is my almost finished "prepper" layout w 36.5 kWh of PylonTech batteries setup as ESS with Grid disconnect.

The Victron Cerbo GX controller now supports Node-Red directly - making custom actions really easy. 

I'm installing batteries right now.. :)

(Attachment Link)

Impressive.
We don't really have enough space for such a system.
 
The following users thanked this post: rthorntn

Offline kaz911

  • Super Contributor
  • ***
  • Posts: 1052
  • Country: gb
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #110 on: June 29, 2023, 11:16:19 am »
It is not that big.

Rack is 600x600mm 46U tall

The only things that take wall space is all my by-pass switches - but you do not really need those.

But you already have a few of the components installed - like the Envoy and DC Bus stuff (where I use 2 x Lynx Distributor boxes)

The Cerbo GX is now available as a "screen and control box" in one unit. But it was released after I bought mine.

Attached is my wall layout.  I oversized (drawing wise) the consumer units. The bypass switches are correct in size. They waste a lot of space which could be done in less space.

 
The following users thanked this post: rthorntn

Offline kaz911

  • Super Contributor
  • ***
  • Posts: 1052
  • Country: gb
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #111 on: June 29, 2023, 11:30:34 am »
Btw - I'm using https://solcast.com to calculate "roughly" how much cloud based solar shade I will have during the day.

So every night before our "cheap electricity" rates - I fetch the forecast - and then set the batteries to "charge" on the low tariff leaving space for the predicted next day solar charge. 

I have multiple roofs - so in Solcast I defined 2 roofs (2 = free) - and set solcast to capacity being 1 kW each. Then it is easy to scale up if I have 3.5 kW South East and 5 kW from WSW - then it is just a multiplier.  (Still adding solar panels)

It is not perfect - but it works - and with the new Node-Red implementation - I can move everything onto the Cerbo GX and let Victron handle fetch and calculation of battery charge target overnight.

/k
 
The following users thanked this post: rthorntn

Offline kaz911

  • Super Contributor
  • ***
  • Posts: 1052
  • Country: gb
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #112 on: July 12, 2023, 05:46:12 pm »
Seem like Victron read my mind about Solcast forecast...

New version of Victron VRM tools implement Solcast "forecasts" for solar radiation

So far no action is taken based on the forecast - but you can use the forecast with the Node-Red implementation - and it makes my programming a lot easier!  :)

Later it can help auto configure battery charge etc as my SW did.

Link to blog post full of ... hmm buzzzz words

https://www.victronenergy.com/blog/2023/07/05/new-vrm-solar-production-forecast-feature/
 

Offline victorb

  • Contributor
  • !
  • Posts: 25
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #113 on: April 05, 2024, 07:44:55 pm »
I was in the same boat a while back. Ended up going for a heat pump system myself. It felt like a bit of a gamble at first because of the upfront cost, but honestly, it's been a winner for me. The efficiency and the savings on the energy bills have been pretty noticeable. Plus, it's a greener choice, which kinda gives me some eco-creds.

When I was making my decision, I got a hand from the folks over at a https://silverwaterplumbing.com.au/plumber-sydney/. They were super helpful, breaking down the pros and cons for my specific situation. Made the whole decision a lot easier to navigate.
« Last Edit: April 08, 2024, 05:06:36 pm by victorb »
 

Offline Steve2600

  • Newbie
  • Posts: 1
  • Country: au
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #114 on: April 21, 2024, 02:21:14 am »
I've been following the install since the original video went up and was wondering if the Reclaim still met your expectations?

I'm not referring to just the running costs, but whether its features and overall performance justify the premium price for this brand? Was the size the right one in hindsight (I'm thinking about recovery time vs capital cost)?

We have just bought a house built in about 2007 and it has a heat pump that is still going, which I think is pretty impressive, but we are getting ready for the day it goes. The Reclaim is top of my list but the cost would be several thousand above the lower end ones like iStore and Hydrotherm. I also use Home Assistant and would love to use the data.

A follow up review on YT would be nice.

 

Offline rthorntn

  • Frequent Contributor
  • **
  • Posts: 402
  • Country: au
Re: Heat Pump Hot Water System vs Gas Hot Water
« Reply #115 on: April 21, 2024, 03:31:12 am »
I've got the smallest stainless tank with the wifi.

I'm using mode 6, it heats up at 6am and then again at 1pm.

Is it worth it, hard to say after 6 months with no issues, it's overpriced imho.

A friend of mine got one of the social media cheap heat pumps, his total out of pocket was $50, my out of pocket was 100x that.

Afaict domotics support is garbage and doesn't seem to be a priority.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf