Sunamp heat battery for DHW only

scubajoe

I tried several times to get info from Sunamp but apart from an initial sales call when I asked for more information on specific points. I never received the info.

anon_ymous

scubajoe said:

I tried several times to get info from Sunamp but apart from an initial sales call when I asked for more information on specific points. I never received the info.

They do like to be quite vague. It's not great for their PR if they're that vague. 

Martyn1981

Have to say, I think the product idea, using phase change material, is really good. And as they say, minimises losses, and size. So don't want to appear to be bashing them .....

But .... I just can't get past the cost, which for a really large one (for my sister's property) was over £4k. Hence my calcs, assuming a £2k saving (and I was being generous), v's ~1kWh of loss per day during non-heating months. The salesman's tactic of over-egging the losses for a HW tank, didn't help, as they seem to be using quite old numbers, not comparing fairly to better insulated modern units. Great to see QrizB's numbers confirming losses are now smaller.

JSHarris

I installed a 9kWh Sunamp in 2018.  Very, very pleased with it overall.  Massively more efficient than the very well insulated (3 year old) hot water cylinder we used to have.  The heat loss per day from the Sunamp is about a 1/5th of that from the hot water cylinder.

The Sunamp is a lot smaller, but also a bloody site heavier.  The weight made it a nightmare to installer.  Getting it up the stairs took half a day and a great deal of swearing.  It weighs around 150kg!

As a company Sunamp started off well, but seem to have sold out to some very dubious snake oil marketing people.  I was lucky enough to buy from them when they still let their (very good) technical staff talk to customers.  They accredited me as an installer after 40 minutes on the phone with their technical guru.  He was very good indeed.

If you don't want the efficiency benefit over a hot water cylinder, don't want the hassle of shifting a 150kg lump around and have the room, then fit a well-insulated hot water cylinder.  It will be cheaper and any competent heating person can work on it.  Having experienced the performance of the Sunamp I'd not go back to a hot water cylinder.

As an example of the very low heat losses, we went away for Christmas just before the pandemic.  I turned the hot water off before we went away.  We got back 5 days later to find the Sunamp was still putting out loads of hot water, despite not having been heated for days.

QrizB

Bumping this thread to say that if anyone wants to play with a Sunamp there's a lightly used one on eBay right now for £800 (branded Fischer, but don't let that put you off).

https://www.ebay.co.uk/itm/334966523338

It's in Essex.

I would be tempted but have had some hefty motor vehicle repair bills recently that have eaten into my gadget budget!

Solarchaser

Hmm, wish I'd seen this earlier.... not that I really have a spare £800, but I'd have liked to play, and potentially add it into my hot water tanks circuit.
Ahh well, maybe I'll start looking out for them on ebay