Which System?!

[squarepeg]

Hi,

I've got a 200 year old house with no heating or hot water. It's 3 storey, with 6 bedrooms (although some will be used as living space) and probably 3 bathrooms. I'm looking into zoned heating. We would however, need at least 12 zones. Underfloor heating isn't an option, and the water tank is likely to be on the ground floor, and the ceilings are pretty high (head height of about 7m?!) In some rooms we will need probably three heating periods during the day. We would also like the facility to include solar water heating in future, although we would not be installing this for at least a year.

I'm thinking that what we probably need is an unvented tank (2 coil) with system boiler and some form of zoning control system. I've seen the JG and Upenor systems...are they any good? are there any others around that I should look at?! Also, I'm thinking the pump will need to be pretty major - any suggestions?

Does anyone have any advice / comments? javascript:emoticon('')
Confused

Thanks in advance for all your help!

 

[gas4you]

My first response would be as a question. Why 12 zones

 

[simond]

12 zones sounds sensible to me because older properties lose heat very quickly, and you either chuck loads of heat into them or use your energy selectively according to occupation patterns.

I suggest you fit the Honeywell Hometronic system to achieve your aims, I have it in my house and we have 5 more installs to do in the next couple of months. 16 zones comes as standard. Solar is a waste of money, but it is your money!

I think you will be surprised how big your pump doesn't have to be on a properly executed system, but that is another story.

 

[Balenza]

squarepeg wrote

and the ceilings are pretty high (head height of about 7m)

Are you saying the ceiling height for each level is over 20 feet high ?.
This would make the building over 60 feet tall over the three levels ?.
Rather you than me trying to heat this.

 

[Balenza]

Simond wrote

12 zones sounds sensible to me

It sounds way over the top to me.

I suggest you fit the Honeywell Hometronic system to achieve your aims

How much would this cost ?.

16 zones comes as standard

Does each zone have its own independent timebase with 1 hour boost function ?.

 

[simond]

How much would this cost ?.

Depends how many radiators/UFH zones. Not allowed to give quotes under forum rules.

Does each zone have its own independent timebase with 1 hour boost function ?.

You can assign up to 1600 temperature/time setpoints over 7 day period. You can set 'lifestyles' for guests, Hogmanay, Bar mitzvah. You can close blinds when the wind gets up. You can learn which lights you turn on and off and replay it when you go out.

Is that enough? PS: It doesn't bake you a cake, but can turn the oven on and off.

NB: I have a 5 bed house, I use all 16 zones for zoning my rads and other switching for hot water, whole house ventilation fan speed etc.

 

[Balenza]

Simond wrote

I use all 16 zones for zoning my rads and other switching for hot water, whole house ventilation fan speed etc.

So you have individual wall stats for each rad or group of rads that are located in each room or area with this system and actuaters connected directly to the rad valves or located at a manifold perhaps ?.

Not allowed to give quotes under forum rules

No one is asking for a quote.
How much does the Honeywell Hometronic unit alone cost ?. It will be helpful to the OP I am sure.

 

[simond]

Controller about £550.

The actuators are effectively radio enabled TRVs, with internal temp sensors and motors.

Using Hometronic you can take a big house with existing pipework and zone it; easy.

 

[simond]

Simond wrote

12 zones sounds sensible to me

Balenza wrote

It sounds way over the top to me.

Do you have one light switch for your whole house?

Can you not see the sense (and economy) in only using energy to heat the rooms you are actually using at a particular time of day?

Sometimes I think this industry is still in the dark ages.

 

[squarepeg]

Thanks for all the replies - we're looking at 12 zones because not only is it a big draughty house with three storeys (so one storey has direct to earth floor (cold) one has heated rooms above and below (relatively warm) and one has heated below, but cold above (will insulate as best we can...) but also it's north / south facing, so on each floor we have one room that is really warm even if there's only a little sun, and the other rooms are cold.

In addition to this, one room will be used as a home office (needs to be warm during the day - don't really care about the evening) whilst a lot of the rest of the house won't be inhabited during the day.

Given that heating costs are going to be large anyway (looking at at least 30kW boiler) we would like to zone to minimise costs!

The head height from the cylinder to the top floor will be about 7m - the ceilings aren't 7m high!

Thanks for the advice!

 

[gas4you]

Now I understand your reasoning Simon. I had totally forgot about this easy to fit system.

I had pictured in my mind 12 2 port valves all having to be wired up and each with a room stat

 

[BigBurner]

Tank? Do you mean DHW cylinder? 12 zones? nothing wrong with that. Solar? I would tend to go for a thermal store with a DHW plate heat exchanger. These are far better for solar than other cylinders. The CH can be run from the thermal store from a coil and have zone valves in batteries on each floor, or all in one battery on the ground floor. A thermal store can cope with only one small zone on, while large boiler will be inefficient and have restricted flow through it. What is the mains water pressure like? How many bathrooms?

 

[squarepeg]

Thanks again - yes by water tank I mean DHW cylinder. We're probably going to have three bath / shower rooms (one per floor). Mains water pressure is very good (don't know exact pressure, but very high).

on teh note of thermal stores - am I right in thinking that we heat a small amount of stored water in the heat exchanger, by solar, gas boiler or a combination of both, which is then used to heat water in the DHW cylinder and central heating system?

Do you mean that a large boiler will be inneficcient in the original set up, or with the thermal store? i'm also concerned by teh comment that they can only cope with one small zone on?? I'm sure I'm misunderstanding this (as you can probably tell, I'm a newbie at choosing systems - alright at replacing bits, but specifying an entirely new system is mindboggling! ) so thanks for your assistance.

 

[BigBurner]

Thanks again - yes by water tank I mean DHW cylinder. We're probably going to have three bath / shower rooms (one per floor). Mains water pressure is very good (don't know exact pressure, but very high).

on teh note of thermal stores - am I right in thinking that we heat a small amount of stored water in the heat exchanger, by solar, gas boiler or a combination of both, which is then used to heat water in the DHW cylinder and central heating system?

Yes,I think you have it. The water in the cylinder is heated by solar, your boiler and the immersion too. The cylinder water is pumped to the rads and it does DHW too giving instantly heated high pressure DHW. Legionella is nearly eliminated. The hot water can be drunk as with a combi or unvented cylinder. So you have full electric backup as well.

Do you mean that a large boiler will be inneficcient in the original set up, or with the thermal store?

Not with a thermal store. The boiler only heats the store of water in the cylinder in one big burn. The advantage is no boiler cycling. When heating one or two zones a big boiler is very inefficient. On part load (less than maximum) they are also less efficient. When heating a cylinder of water directly with heat exchanger between, they are nearly always on full load.

For multi fuel applications a vented thermal store is the best option by far. When zoning, you don't need a central room stat to switch off the boiler as you will when the boiler is directly heating the rads. A Grundfoss Alpha pump can be used on CH circuit as it will automatically run down its speed when zones are switch off.

I hope that helps a little.

 

[PerpetualLeakingRoof]

Thanks - Must admit I've been looking at Grundfos alpha pumps, although I'm not sure whether I should go for one for DHW and one for CH or just go for the one (pretty big house!). Suppose I need to spend a bit more time thinking about head heights, volumes and specifications!

Good to know that you think I've got the idea of the thermal store - now I've only got the rest of it to go...