The ACV Heatmaster 35 KW combi supplies 38 litres per minute of hot water at 60 degree C. I have all the details. As you are now going to buy one as it beats your 30 litres, take out a loan tomorrow as you have clearly stated.
30 litres a minute from a tank in the loft? I would say 28mm pipes and 3/4" single bath taps to get that. Who has single taps anymore? I have only ever seen them in hospitals. I only ever fit mixers which do lower the combined flow. Single taps lower the price of a place.
Peter,
There are stored water combis. They have everything in one box with some stored water inside. You don't get too concerned about the innards. The ACV Heatmaster will deliver 38 litres per minute and is only 35 KW. The domestic meter will deliver around 60 KW. 35KW is just over half of the meter capacity, so just ticking over. The Powermax, Gledhill and Viessmann both have high flowrates as well.
The Japanese Rinnai multi points have high flowrates with the downside of no CH. I am seriously in the market for one of these.
Clearly you haven't read them properly, or have just looked at the glossy brochure. Have you been taking dIMM pills.?
That is the short term peak value.
The HM35TC is claimed to be able to deliver 224 litres per 10 minutes at 60 degrees.
However, the constant flow rate is 9.6 litres per minute at the same temperature rise of 50 degrees. At the more commonly quoted temperature rise of 35 degrees, the constant flow rate is 15 litres per minute which is as predicted by the appliance rating.
They conveniently omit what the size of hot water storage actually is, so that one cannot determine the real performance of the system.
The sales brochure describes the unit as "light weight". Hmmm... the spec. says 170kg empty.
It's also described as "small". The actual size is 670 x 600 x 1700 which is hardly that. It won't even fit into a standard washing machine footprint. This means that it will either be taking up valuable space in a kitchen (which would have to configured in a non-standard way, or to be placed in a cupboard. In effect, the size is the same as a storage tank and there is virtually no usable space saving compared with a conventional cylinder and separate small boiler.
This is not to say that the design isn't reasonable in principle, but there is considerable specmanship and hype in the way it's described.
You should be.
It will do that for an unspecified short time. Refer to other post.
For a short period. It is not possible to get a quart from a pint pot.
I expect that the marketing guy is rubbing his hands with glee.
I suspect he is dIMM....
Total crap, if there is either a separate shower enclosure or mixer were is the need for mixer taps?
60 degrees? Do you want to have third degree burns? Do you know how hot that is?
I downloaded the installation manual. Here are the figures pasted in for you, which are very impressive:
---------- DOMESTIC HOT WATER FEATURES HeatMaster=C2=AE Operating conditions at 80=C2=B0C 35 TC
Peak flow at 40=C2=B0C [=CE=94T =3D 30=C2=B0C] L/10=E2=80=99 419 Peak flow at 40=C2=B0C [=CE=94T =3D 30=C2=B0C] L/60=E2=80=99 1312 Constant flow at 40=C2=B0C [=CE=94T =3D 30=C2=B0C] L/h 1057 Peak flow at 45=C2=B0C [=CE=94T =3D 35=C2=B0C] L/10=E2=80=99 381 Peak flow at 45=C2=B0C [=CE=94T =3D 35=C2=B0C] L/60=E2=80=99 1080 Constant flow at 45=C2=B0C [=CE=94T =3D 35=C2=B0C] L/h 898 Peak flow at 60=C2=B0C [=CE=94T =3D 50=C2=B0C] L/10=E2=80=99 224 Peak flow at 60=C2=B0C [=CE=94T =3D 50=C2=B0C] L/60=E2=80=99 692 Constant flow at 60=C2=B0C [=CE=94T =3D 50=C2=B0C] L/h 578
Pre-heat time minutes 37
---------
It will deliver 381 litres for 10 minutes at a sensible 45C. That is 38 litres per minute, then drops down to 15 litres per minute continuously never running out of hot water. Many people on this thread are happy with less than 15 litres per minutes from their combis. Two simultaneous baths can be filled. The mains pipe temperature is around
20C at the moment, the ACV would right now deliver 42 litres per minute for 10 minutes, then down to near 18 litres per minute. That will fill a large jacuzzi no problem at all. The figures are very impressive and I have no reason to disbelieve them as ACV are largely in the commercial market. The new Scottish Parliament building has banks of Heatmasters. See the ACV web site.
There is space savings. No boiler in the kitchen, which are a pain and restricts kitchen design, which is great bonus for me. The ACV can go in then loft like the Powermaxes. A bit of a lift but possible. I asked ACV about loft mounting they said no problems as the unit is well insulated.
I don't quite understand how it works in detail. ACV have configured a lower chamber to force cool water for the condensing operation. Perhaps IMM/Evil can explain. It is all stainless steel which says a lot. I would not say there is hype in the table I pasted above. It is very clear. Having over the past 7 years looked at combis that save space and deliver high flows, the ACV is the most impressive I have seen by far. It is also one of the most efficient boioers around, whoch is a good plus point on selling. A rennovated house with a high efficient quality boiler makes it easier to sell. I=E2=80=99m not sure if it is up to high continuous flows that the Rinnai delivers for a couple of simultaneous Tower Showers. The ACV is on the shortlist for the next job, as is a Rinnai. =20
I wish all my buyers were as easy to please as you, as I would save a fortune and put in cheap contractor materials.
I am only interested in what the combi delivers in flowrates. How it works inside is only of passive interest.
Please do refer to my other post. The time is not unspecified, it is clearly 10 minutes. It will fill a 380 litre bath in 10 minutes and a normal bath in a few minutes.
The Powermax, Gledhill and Viessmann are all two bathroom models, and then drop down to basic low flow continuously. The high flows are enough to fill baths and have two simultaneous showers.
He should be as they are the biggest seller in the world. I'm off to Travis Perkins now.
In article , snipped-for-privacy@my-deja.com writes
I think you're stretching it a bit timegoesby, how much do single taps lower the price by? and have you had any experiences specifically about that?
It sounds fine, much nicer than an instantaneous combi. However it is just a storage system boxed into one unit. There's nothing particularly novel about it. Plenty of types of this system are available, whether based on heat banks or unvented cylinders.
I don't see how 600x670x1700 is particularly space saving. Nor does it have a monopoly on loft installation.
My system (WB Greenstar HE28 + 180L DPS Pandora) as installed has almost identical performance to the published figures and was probably a lot easier to get into the loft, too. It also has electric backup (which I used for several months, as the boiler was not ready for installation). Does the ACV have this? It may do, I don't know.
Christian.
What do you plan to use for heating though?
You have about 60kW to play with from the supply. Space heating boilers are going to be at least 15kW. If you have other gas appliances such as a cooker you potentially lose another 5 to 10kW there. At best that seems to leave you 40kW to play with for the Riannai.
That does not sound any better than one of the bigger combi's, but requires two boxes to do it.
There is no shortage of cheap contractor mixer taps available.
mixer
Now you are changing your goal posts, first you talked of types of tap, now you seem to be talking about the 'cosmetic design' of taps - sound like you have been taking lessons in being a simpleton from IMM....
You quoted the 60 degree figure in the first place.
They are not impressive at all. This is a game of specmanship only and they are not defying physics.
It is not clear that this is what it means at all. The figure is quoted as 381 litres per 10 minutes. Clearly it can't deliver that for every period of 10 minutes on an ongoing basis, so is a multiplication exercise.
Once the store is exhausted, and it doesn't say how large the store is, is takes a further 37 minutes to recover.
It would also assume that the mains supply is able to deliver 38lpm and that is a huge assumption.
For "many" I think that the accurate description is "a few". Certainly it's less than 50%.
Irrelevant. The important point of any design is the performance under worst case conditions.
I don't disbelieve the figures, once one works out what they actually mean and not taking the best case conditions as has been done in your dIMMesque approach.
This is a recommendation?
In terms of *usable* space there is virtually nothing.
It's substantially less restricting to accomodate a wall mounted system boiler in the kitchen or any one of a number of other places that to try to fit in a non-standard sized hunk of metal in the kitchen.
170kg then the water in addition with unpsecified weight?What about the crane and getting it through the hatch? Are you sure that the access is wide enough between joists that are on 600mm centres to fit a 600mm wide appliance through?
Perhaps it would be an idea to take off the roof and hire a crane to save the tiny amount of space you had in mind.
Conveniently ignoring the weight and access factors. Obviously the thing is well insulated.
That could be entertaining.
It says that the materials used are of good quality as long as the correct grade has been used.
IThere is a lot of inconvenient information missing. How heavy is it with water and how large is the store?
That doesn't say much for the rest.
It is 1% more efficient on the SEDBUK scale than other products and the BRE point out that there is a 5% uncertainty of measurement anyway.
Read the numbers carefully. There is a lot of missing data.
I suppose that that would be true in the small time property speculation market.
That is not what they explicitly say in the spec.
They give the rate per 10 minutes which is not the same and it cannot be continuous.
There is no meaning in the expression "two bathroom model". Without explicit specs there is nothing to compare.
Does dIMM work there?
As far as I interpret the figures it is saying (at delta 35):
38lpm for 10 minutes from full store to depleted. 18lpm for 60 minutes from full store to depleted. 15lpm continuous.With a 37 minute recovery.
In which case, I would conclude (and from the casing dimensions) that it has a very sizeable store. Assuming it is essentially a heatbank, I'd guess (10*(38-15)) * (35 / 70) = 115L (assuming heat store at 75C, incoming mains at 5C), plus a few litres for inefficiency, which is essentially a standard
450x900 cylinder. Indeed, it sounds so like it, it probably is it.The only spoiler is the quoted 37 minute recovery. The 23lpm (38-15) delta
35 water should only take 23*10/15 minutes to recover, which is just under 16 minutes, although it might just be to cover a slow ramping down of the recovery rate towards the end, which might suggest an indirect coil method of heating.If it is an unvented cylinder without TMV at 60C, then I make the size (10*(38-15)) * (35 / 55) = 146L plus a bit.
Christian.
They look cheap too. Having a top quality bath and tiles and then fitting cheap taps is like making a Rolls Royce and fitting cheap plastic seats.
I have never had the experince as I always fit good quality mixers, preferably the one lever type, the sort the buyers expect, the sort that stand out, the sort that say quality, the sort that say I like this bathroom, the sort that add value and make the place sell for the asking price very quickly.
Indeed. However, pillar taps are not necessarily cheap. Just because the cheapest taps are some horrible 3.99 plastic compression washer monstrosities, doesn't mean that all separate taps are like this.
I actually prefer having separate taps in a basin. I believe it looks more appropriate in the period properties I prefer to frequent. However, the ideal installation costs more than a single monobloc mixer of similar quality, as a basin really benefits from a genuine cold tap (mains drinking water) and a TMV mixed 40C hot tap for shaving/hand washing/etc.
Christian.
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