Sunamp Video

[Guest Alphonsox]

Here's my set up delivered last week and not yet installed. This is a Sunamp Expansion unit storing a total of 10Kw (5Kw per box). From the external viewpoint these are very simple units with a cold in, hot out plus a 240V electrical feed. Internally there is a mixer valve to set the outlet temperature variable between 35-65C. A standard 5Kw unit is specified as being able to supply 140litres of water at 40C so I am expecting around twice that from this unit. Standby losses should be around 1Kw per day. I'm intending to feed this from E7 electricity, PV may be added later. (Please note the "measure" is not supplied as standard.)

 

EDIT:- I should note that this unit is extremely well made with a 2mm powder coated metal case, Grundfos pump etc.

 

[PeterW]

1 hour ago, Nickfromwales said:

Dont flatter yourself lol. I'll 'do it' for the good of the thread / members  too and, tbph, I want to know for myself as I may well start promoting these through my business. . 

To summarise, that's 2 members at 3 pints each so next Friday eve is covered ????

Sweet. 

 

Dont forget the "consultancy" charge ... I was interested if one of these could actually work with a recirculating flow rather than the mains cold to hot / combi fees they promote 

[PeterW]

44 minutes ago, Alphonsox said:

Here's my set up delivered last week and not yet installed. This is a Sunamp Expansion unit storing a total of 10Kw (5Kw per box). From the external viewpoint these are very simple units with a cold in, hot out plus a 240V electrical feed. Internally there is a mixer valve to set the outlet temperature variable between 35-65C. A standard 5Kw unit is specified as being able to supply 140litres of water at 40C so I am expecting around twice that from this unit. Standby losses should be around 1Kw per day. I'm intending to feed this from E7 electricity, PV may be added later. (Please note the "measure" is not supplied as standard.)

 

EDIT:- I should note that this unit is extremely well made with a 2mm powder coated metal case, Grundfos pump etc.

 

 

That looks rather tasty ! What's providing your heating if that is just doing DHW..??

[Stones]

50 minutes ago, Alphonsox said:

Here's my set up delivered last week and not yet installed. This is a Sunamp Expansion unit storing a total of 10Kw (5Kw per box). From the external viewpoint these are very simple units with a cold in, hot out plus a 240V electrical feed. Internally there is a mixer valve to set the outlet temperature variable between 35-65C. A standard 5Kw unit is specified as being able to supply 140litres of water at 40C so I am expecting around twice that from this unit. Standby losses should be around 1Kw per day. I'm intending to feed this from E7 electricity, PV may be added later. (Please note the "measure" is not supplied as standard.)

 

EDIT:- I should note that this unit is extremely well made with a 2mm powder coated metal case, Grundfos pump etc.

 

 

I was looking at exactly this set up as well, but eventually decided against as it was just going to cost too much compared to alternatives.  All of the feedback does seem very good (in terms of both performance and build quality) and Andrew and his team are more than willing to discuss things and develop non standard solutions as above (I can actually take a little bit of credit in persuading Andrew into 'developing' the solution above).

 

I previously looked at the Sunamp Stack as a solution for DHW and heating, but again concluded it wasn't for me.  I think if your DHW and heating demand are low enough, then a Sunamp product could be the ideal solution, assuming your happy with E7 or E10 electricity supply.  

 

[Russdl]

@Nickfromwales Lightweight.

 

Edited October 15, 2016 by Russdl

[Guest Alphonsox]

@PeterW The heating is going to be handled by an ASHP feeding low temperature UFH. I managed to buy a 4Kw Kingspan unit for peanuts a year or so ago. I'm hoping that running this at a low flow temperature will stop the thing freezing up in the very humid environment hereabouts. I'm less convinced that it won't dissolve in the salt air, we are seeing all metal parts attached to the house corroding after just a year or so's exposure.

 

@Stones True the upfront cost of the Sunamps is higher than an equivalent stored water solution but if I factor in the fact that I won't need a part-G installation or the  annual inspections for a UVC then it starts to look competitive. That's before you consider the large space saving and reduction in waste heat.

[Stones]

46 minutes ago, Alphonsox said:

@PeterW The heating is going to be handled by an ASHP feeding low temperature UFH. I managed to buy a 4Kw Kingspan unit for peanuts a year or so ago. I'm hoping that running this at a low flow temperature will stop the thing freezing up in the very humid environment hereabouts. I'm less convinced that it won't dissolve in the salt air, we are seeing all metal parts attached to the house corroding after just a year or so's exposure.

 

@Stones True the upfront cost of the Sunamps is higher than an equivalent stored water solution but if I factor in the fact that I won't need a part-G installation or the  annual inspections for a UVC then it starts to look competitive. That's before you consider the large space saving and reduction in waste heat.

 

Fair point, although for me the installation would have been done by the plumber regardless.  When I factored in the additional costs I would have had (separate provision for kitchen and utility DHW and an ASHP) on top of the Sunamp premium, plus the restrictions of an E7 tariff in relation to our lifestyle, I felt it wasn't the right solution for us.

 

Out of interest, is your ASHP a coastal model?

[Guest Alphonsox]

32 minutes ago, Stones said:

Out of interest, is your ASHP a coastal model?

 

Unfortunately not - It's a basic 4Kw Kingspan unit (badge engineered Carrier unit). It's overwhelming attraction was the price of £150 new - so attractive I bought 2 of them. There is a coating that can be applied to the heat exchanger that I may try - Bygold - but I have yet to do any research to establish whether this will help significantly.

 

[PeterW]

2 hours ago, Alphonsox said:

@PeterW The heating is going to be handled by an ASHP feeding low temperature UFH. I managed to buy a 4Kw Kingspan unit for peanuts a year or so ago. I'm hoping that running this at a low flow temperature will stop the thing freezing up in the very humid environment hereabouts. I'm less convinced that it won't dissolve in the salt air, we are seeing all metal parts attached to the house corroding after just a year or so's exposure.

 

@Stones True the upfront cost of the Sunamps is higher than an equivalent stored water solution but if I factor in the fact that I won't need a part-G installation or the  annual inspections for a UVC then it starts to look competitive. That's before you consider the large space saving and reduction in waste heat.

 

Thanks - sounds like splitting the DHW and heating into two separate functions works for you. Are you planning on any in-line boost post the sunamp or are you expecting to maintain the flow from just the units themselves ..?

[Guest Alphonsox]

6 minutes ago, PeterW said:

 

Thanks - sounds like splitting the DHW and heating into two separate functions works for you. Are you planning on any in-line boost post the sunamp or are you expecting to maintain the flow from just the units themselves ..?

 

I'm hoping the 10Kw from the Sunamps will be sufficient for our needs. However I have wired for an electric boost unit should it be necessary.

[Frogeye]

 

@Alphonsox  Are you prepared to share with us a ball park figure of cost for a 10kwh setup like this? 

[Stones]

I posted about cost in the 4 cell Sunamp topic I linked to earlier.

[Barney12]

5 minutes ago, Stones said:

I posted about cost in the 4 cell Sunamp topic I linked to earlier.

 

You did indeed but to work out the price you would need to know the cost of a single unit which unless I'm being blind isn't readily available? 

[Stones]

When I was looking at it, a single Sunamp PV was £1700, and they were offering two units buy one get the second half price (so £2550).  

Edited October 17, 2016 by Stones

[Barney12]

1 minute ago, Stones said:

When I was looking at it, a single Sunamp PV was £1700, and they were offering two complete units buy one get the second half price (so £2550).  

 

Thanks. Considering the simplicity of install (as I understand it) and removal of some expensive components such as tanks and ASHP then it could be very viable provided you have a reasonable PV array.??

[PeterW]

I think you need to consider TCO as a tank is £750 and an ASHP can be had for £1300. Assuming you have PV it's fine - just on E7 it may be tight on the overall cost. 

 

On top you need a space heating solution - ASHP could be the answer here as Neil has done  

 

Sunamp does sound attractive though ! 

[Stones]

Agreed, with no PV the figures simply didn't stack up for us, and didn't want to go down the E7 or E10 route.  I think it really does depend on your individual circumstances and DHW / heating requirements . 

 

Despite my decision, I still think it's a great bit of kit.

[Barney12]

22 minutes ago, PeterW said:

I think you need to consider TCO as a tank is £750 and an ASHP can be had for £1300. Assuming you have PV it's fine - just on E7 it may be tight on the overall cost. 

 

On top you need a space heating solution - ASHP could be the answer here as Neil has done  

 

Sunamp does sound attractive though ! 

 

Im still favouring the idea of:

 

ASHP to heat a thermal store (buffer? Not sure I completely understand the difference ! @Nickfromwales Help!!) to a level that ensures maximum COP. Which then feeds a) low temp underfloor heating b) a Sunamp which will boost the temperature for DHW. 

I assume the store will need an immersion to provide a legionella avoiding boost.

 

BUT, the simplicity of just the Sunamp for UFH and DHW is attractive. I can cope with simple  

 

I should add that our DHW requirement is fairly low with just two of us. Our current little flat is served by a 80ltr Zip Aquapoint III electric unvented water heater. 

https://www.plumbnation.co.uk/site/zip-aquapoint-iii-unvented-80l-water-heater--multiple-outlet-/?gclid=CO6sr4bj4s8CFRdmGwodpQ0G5A

and although on 24/7 it provides more than enough oomph for two morning showers and the breakfast dishes! 

Edited October 17, 2016 by Barney12

[PeterW]

23 minutes ago, Barney12 said:

assume the store will need an immersion to provide a legionella avoiding boost

 

Thermal Store is a large unpressurised body of water kept hot with a small volume coil at mains pressure with potable water going through it.

 

UVC is a large body of potable hot water kept at mains pressure with a low volume heating coil within it. 

 

As the volume of potable water in a TS is so small you don't have the legionalla risk as you do storing large quantities at risk temperatures. 

 

The sunamp acts like a phase change TS in essence.  

[TerryE]

IMO, using the SunAmp as a thermal store for UFH is overkill. You've already got maybe 7m³ of concrete to do that. In a passive house with typical losses you can pump the heat into the slab when economic to do so and let the temperature vary maybe 1°C, for example with E7 or E7 powered ASHP.  KISS.

 

@Stones Jason, I am going for E7, partially because I think that within 5 years we will have consumer spot pricing tarrif options. It's really only a software issue now, and doing so is really going to help the generators optimise supply / demand management.

 

In terms of overall design, we seem to be pretty much paralleling @Alphonsox Neil apart from the sea air of course.  The only main difference is that I am not going to fit my ASHP for completion, but use just electricity for the first year or so, so we can characterise and size our system needs and fit the ASHP as a year 2 upgrade.

 

Edited October 17, 2016 by TerryE

[Barney12]

8 hours ago, TerryE said:

IMO, using the SunAmp as a thermal store for UFH is overkill. You've already got maybe 7m³ of concrete to do that. In a passive house with typical losses you can pump the heat into the slab when economic to do so and let the temperature vary maybe 1°C, for example with E7 or E7 powered ASHP.  KISS.

 

 

Thanks Terry. So how will you heat the water for your UFH? I.e. In what sort of store? Or some sort of inline immersion? 

[Barney12]

8 hours ago, PeterW said:

 

Thermal Store is a large unpressurised body of water kept hot with a small volume coil at mains pressure with potable water going through it.

 

UVC is a large body of potable hot water kept at mains pressure with a low volume heating coil within it. 

 

As the volume of potable water in a TS is so small you don't have the legionalla risk as you do storing large quantities at risk temperatures. 

 

The sunamp acts like a phase change TS in essence.  

 

Yep, I get that. But what defines the term "buffer"?

 

Sorry if I'm being thick  

[Nickfromwales]

8 hours ago, TerryE said:

IMO, using the SunAmp as a thermal store for UFH is overkill. You've already got maybe 7m³ of concrete to do that. In a passive house with typical losses you can pump the heat into the slab when economic to do so and let the temperature vary maybe 1°C, for example with E7 or E7 powered ASHP.  KISS.

 

@Stones Jason, I am going for E7, partially because I think that within 5 years we will have consumer spot pricing tarrif options. It's really only a software issue now, and doing so is really going to help the generators optimise supply / demand management.

 

In terms of overall design, we seem to be pretty much paralleling @Alphonsox Neil apart from the sea air of course.  The only main difference is that I am not going to fit my ASHP for completion, but use just electricity for the first year or so, so we can characterise and size our system needs and fit the ASHP as a year 2 upgrade.

 

Isn't the slab an emitter not a storage device?

[Nickfromwales]

6 minutes ago, Barney12 said:

But what defines the term "buffer"?

A buffer is basically a wet capacitor that acts as a sponge which absorbs energy and smooths out the delivery. Heating goes via that so, for eg, Ufh can draw lower amounts of heat than the heat source can provide ( lowest modulation / temp setting etc ) when the house is up to 'operating' temperature. 

It is a TS in essence, but we normally name the two differently when more than one application is required from said vessel. Eg when you add another coil for dhw production you'd typically then not refer to it as a buffer as it's not just a dumb vessel anymore. 

[Guest Alphonsox]

43 minutes ago, Nickfromwales said:

Isn't the slab an emitter not a storage device?

Effectively it's both just like an old fashioned storage heater. In our case we 100m² of concrete floor at around 8cm deep.

This is 8m³ or around 19000 Kg. The heat capacity of concrete is 880 J/kg/C so my floor stores around 16000 kJ/C or around 4,5kWh/C

So if I heat the floor to 20C it needs to emit  4.5kWh to drop to a temperature of 19C. According to Jeremy's heat loss spreadsheet (and SAP) the house should require around 1.5kW to maintain a 20C temperature when its 0C outside. Factoring in additional energy gains from people actually living in the house and the fact that it rarely if ever drops to freezing, I'm hoping that the UFH may never need to be heated outside of the E7 period.