Dimplex Quantum

Fairzo

Hi all, we have two Dimplex Duoheat fail so need to replace. Any recommendations other than Quantum?

The living room size is roughly 15 sq. m. and so the QM150 would, theoretically, be required. Unsure if this is overkill but I suppose it's preferable to having to use the boost?

Thoughts welcome.

Ildhund

I have a QM150 in my 30m² living room. My problem is gross underkill - it's never managed to get the temperature above 18º even when it's not particularly cold outside. It's supposed to heat 15m², but so much depends on ceiling height, insulation, draughts etc. that this will never be more than a guide. 

Scot_39

I had a look at a couple of heat shop style vendors of the RF's the other morning for a question in another forum post.

From the top couple who came up on google - one said the RF150 was good for 15 sqm - the other only 11 sqm.

So only 1 for 15m2 might be a push.

My elderly neighbours - end of terrace - c14 qs m - modern - cavity wall etc - but 2 external walls and a large metal framed sliding patio door - ended up with a 150 and iirc a 100 in slave mode - to be sure of hitting 21 without use of boost - when they had quotes from a couple of installers.

Dimplex have a heater rating tool - it asks questions about sizes, walls, floors etc and gives a rating - give it a go.

https://www.dimplex.co.uk/en-gb/room-heating-calculator

(Note if select Quantums it gives you input peak ratings in terms of charge ratings (so compare to 3.3kW on 150 iirc) - not heater ouput ratings (1.5kW on 150) - based I assume on 7 hours of E7 charging max) - and does the calc for -3C default external - but recommends changing that to -5 for Scotland - or did - iirc)

Fairzo

Thanks for that. I remembered using that calculator before when it seemed like the Duoheat was failing.

I've put the dimensions etc. in and the results fed back make no sense to me. Appears to be just random numbers.

I'm taking some comfort in that the Duoheat (500i), despite throwing out heat during the charging period and kept going until at least 10 p.m. without the need for a boost.

Scot_39

I ran it again recently - just beofre posting the link for another user - just for my living room just recently - it did recommend around 3 kW input - so the largest RF 150 model - needed.  

My old one takes 3.6kW but is passively vented with a max output just sub 1.1 kW iirc (the quantum quotes 1.5kW - but can only take c23kWh charge on E7 - not 36kW of charge - so it's a max rather than rated - unless rely on some of 17hrs at peak rate boost)

c4 years ago i did all rooms - inc kitchen bathroom and bedrooms (each has own heating - panels or wall mounted fans - but for which I normally just rely on two medium sized NSH in halls to heat sufficiently for my purposes.)

And again it didn't seem too bad - but I did have to lower the room temps from their defaults of 21 and 18 - to get anywhere near close to my typical max winter day use - it was more like my worst case beast from the easat than typical - but it's meant to be - so as heaters rated to cope with -VE external temperatures.

It's a typical worst case rating - not a normal winters day rating as it were - so the numbers are worryingly high.

I would be in trouble - with really high bills - if I regularly maxed out my 3 NSH - I have 7kW input power - maybe just over 2kW output - but whilst it can be varied (vent flow opening) - on average it's enough for me.

And as on E10 split 3 tmes per day - they could even manage to take potentially closer to the max 70kWh - than an E7 rating calc would allow - certainly with nearly 8 hours to cool end overnight (12- 5am) to mid afternoon charge (1-4pm) slots - could take a decent chunk - even on low to mid brick thermostat input setting - they do regualrly take extra charge 3x per day.

The input power basis - when change heater type to storage from say panel type - is certainly a sharp shock to senses - but it's kind of understandable - as the aim is for max off peak use at cheap rates.