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Sunamp Stack

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#1 stones


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Posted 25 November 2015 - 02:17 PM

I'm currently looking into this product for my new build. As other members have experienced, Andrew @ Sunamp has been very helpful in providing information.


The main attraction of this unit is the ability to store up to 60 kWh of useable heat energy. For low energy houses, this meets and probably vastly exceeds the total DHW and heating energy requirements.

The following info is a summary of the information provided by Andrew (if I have got any of it wrong, Andrew said he would correct it)

The unit is currently progressing through testing, but should become available in Spring 2016.

As yet Sunamp do not have any heat loss data for the unit, but given that the casing will be made of the same vacuum panels as the Sunamp PV is made from, I think we can expect low losses (certainly lower than a suitably sized thermal store).

The storage medium with the unit are the same PCM cells as the Sunamp PV. These are designed to have a 20 year lifespan, warranty for 10 years.

Each PCM cell stores between 2.2 and 2.5kWh. Eventual output depends on unit configuration.

The Sunamp Stack is a storage unit only. It would need to be paired with a heat source - electric flow boiler in my case.

Preferred output temp set for DHW to give maximum flexibility. This would mean blending down for UFH applications.

Due to testing and conformity requirements, it is unlikely that they will offer a a unit with a PV charge capability (as per the Sunamp PV).

The unit can be configured in several different ways, with full size units measuring approx 550mm x 550mm x 2100mm (16 cells) or 800mm x 550mm x 1600mm (18 cells). One interesting thread of our discussion was the option / possibility of buying a full sized housing, racking system and internal hydraulics, but only installing a limited number of cells, which could be added to later if total demand exceeded what was planned (for whatever reason).

A full size unit would allow households to use E7 as their energy source. A smaller sized unit (i.e. limited number of cells) could be run off an E10 tariff, although E10 is somewhat more restrictive in that there are only a few energy suppliers which support that tariff.

Cost wise, Andrew suggested a full size unit would be in the region of £5.5K to £6.5K. If someone wanted a smaller unit, he indicated that the casing/ racking/hydraulics would be £1K-£1.5K, and £250 - £300 per cell. As a tailored/bespoke item rather than a large production run item, individual units would be priced according to individual requirements.

Installer training would be facilitated by Sunamp.

I'm currently number crunching to see what would suit my needs. I still haven't completely discounted the Sunamp PV - although much will no doubt rest on real world test results that Jeremy provides.

#2 gravelld


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Posted 25 November 2015 - 02:32 PM

Could it be used for space heating in some circumstances (low energy build)? Charge at E7, then pump around rads as needed. Better or worse than NSH?

Can different heat inputs be added, like a TS?

#3 stones


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Posted 25 November 2015 - 03:35 PM

Yes, the basic concept is that this unit can store the same amount of energy as a 1000+ litre TS.

I'm looking at it for both DHW and space heating (UFH). Seemingly you could specify the cells to meet specific temperature requirements - higher for DHW, lower for UFH, but the default would be one output temperature set for DHW, which you would then blend down for UFH. I suppose you could run a radiator system if you so wanted.

Better than NSH - going by what we know of the Sunamp PV then I would say yes - faster recharge, high temp output, easy to control.

Edited by stones, 25 November 2015 - 03:36 PM.