Oversized rads a good idea?

[Corgigrouch]

Now this is a Toshiba.....

http://www.toshiba-aircon.co.uk/Pro...Pages/RAS Super Daiseikai High Wall Units.pdf

If you have a decent loft over the bedrooms then you could have a ducted unit..... One air handling unit with air flow and return ducts feeding vents in your ceiling.....

 

[wiffola]

Avoid!..... They are not Toshiba units. The compressor may be sourced from Toshiba but the rest of the components are from somewhere else... If you need parts or a repair, you will struggle to find parts. If you call Toshiba for a warranty repair then they won't be able to help.

If you look closely you will see the word Compressor under the large and convincing looking TOSHIBA logo... I've seen a fair few of these and the quality inside is pretty poor

Thanks for the advice.

Was just getting the ball rolling...what units should I be looking at?

 

[Corgigrouch]

Any decent make, Daikin, Toshiba, Sanyo, Fujitsu, Panasonic..... I fit Sanyo and Fujitsu these days, mainly because my supplier does me a very good price on them and they are nice to install.... Never had one let me down. I have an LG in my living room and although it is OK, I wouldn't recommend them.. I have a little Toshiba RAS10 in my bedroom and it is a lovely quiet little thing....

 

[wiffola]

Thanks for the recommendation.

We have a loft conversion so ducting could be tricky. What size/diameter is the ducting pipe?

Is a single heater unit on the landing to heat 4 rooms crazy? Landing is tiny.

 

[Corgigrouch]

Normally 6 inch insulated flexible ducting (It is pretty dear stuff, don't ask me the price as it has been a long time since I bought some)... I really wouldn't recommend one unit on the landing I know of one unit fitted like that and it just doesn't work very well... Ideally one unit per room ...

 

[Corgigrouch]

Norcon, I have just had a look at the makers of your boiler.... That is a lot of boiler for the cash.... What's the quality like? did you notice anything on the install that gave you any concern?

 

[Norcon]

No nothing. The welding looked superb. It looks as good in real life as in the images. And very heavy. Last time we built boilers like this in the UK Queen Victoria was still on the throne.

 

[wiffola]

It does seem very cheap! I would love to know if there are any downsides?

 

[wiffola]

Also avoid multiple indoor units run from one out door unit, go for a one to one. A ducted unit upstairs in the bedrooms is also an option...

Can anyone explain why a split system is a bad idea...it seems to make sense on paper to have one system running multiple units.

Thanks for any more help

 

[Norcon]

The only downside is the control aspect. The fan would need a separate isolator switch inside the home to turn it off at night. Two in series would even be better with the second one located near the boiler.
After the few parameters are set in the controller the only operation needed is the fan.

 

[Corgigrouch]

Also avoid multiple indoor units run from one out door unit, go for a one to one. A ducted unit upstairs in the bedrooms is also an option...

Can anyone explain why a split system is a bad idea...it seems to make sense on paper to have one system running multiple units.

Thanks for any more help

If your outdoor unit goes down then all your heating goes down... Also with some units, there can be control issues, if someone accidentaly switches one unit to cool mode when the others are calling for heat then the unit won't run and it is a pain to run round the house looking for which unit is out of sync to the others.... Most domestic units have a maximum output of about 9kW (It's been a while since I have fitted one of these so this may be a little out of date) so if you are running four units with an output of 2,5kW then you will not get 2.5 Kw from each unit...

These "Multisplits" are not to be confused with other units (Usually light commercial units) that can have several indoor units connected to one outdoor unit by teeing off the pipework and all indoor units run simultaneously to maintain one common temperature.... these are good to heat one large area and will maintain a more even temperature.

 

[wiffola]

Thanks corgigrouch.

I think that if the main unit goes down all heating goes down doesn't worry me too much, as it's no different to relying on a boiler or air to water ashp. Also we'll have our boiler as a safety net.

The indoor units being set to cooling by mistake...I see what you're saying but I think it's a minor point that doesn't worry me.

Your point about the heat pump not having a high enough wattage to run all units at once... I'd hope that a decent branded system would have this covered but if not then the chances of all units being called upon at once is unlikely with our house. But yeah I'll be very wary of that.

We have 3 rooms downstairs (open plan longe, dining and kitchen) 45m2 total with 2.5m ceilings.
Upstairs we have 3 bedrooms and a small bathroom. 45m2.
Small Loft conversion (very occasionally used)

I see toshiba do a 5:1 split system. Can't find a cost though.

I love the idea of being able to time and zone the house.

2 units down stairs and one in each bedroom upstairs?

 

[Corgigrouch]

Honest!..... You really don't want a multisplit

Do a heat loss calculation for each room.....Remember that you will lose heating capacity as the weather gets colder,so a 9 or 10kW out door unit won't be a 9 or 10kW unit at minus 10.... add to that misty, cold damp nights tend to clog up the evaporators on the outdoor unit with ice and then they have to defrost them selves.... All your indoor units will no longer blow warm air simultaneously whilst this is happening at least with separate units or a twin split, then you will still have some heat somewhere.


The domestic units from any manufacturer only come with infra red remotes, most of which dont have a start timer.If you want to zone the heating, then you will need a light commercial install. these units can be linked and controlled from wall mounted, hard wired control panels

 

[wiffola]

Ok understood - thanks for the help.

Could you point me in the right direction for a ducted system upstairs?

I think a twin split would be enough downstairs?

With the gable end of our semi the install will be straight forward...could you give me a ball park figure for a typical installation?

Thanks again.

 

[DeltaT2]

So the 32kw model you are looking at is nearly £5k for the unit alone.
Plus the buffer store which is another couple of grand and necessary with a gasifier.

This one cost less than £4k completed. Just about to get the weeks garbage tipped into it when I snapped this.....and has saved at least £1000 quids of oil since it was brought online so definately not a step backwards.

No rhi here though. Not yet anyway.
And no sludge buckets either...

Nice work mate........