Air Conditioning and "Heat-Pumps" are really taking off over here in NZ.
Tell me is Air Con a viable form of heating and cooling, where you come from?.
We are starting to have our Open Fires and Coal Heaters banned due to the pollution levels that these things create during the middle of Winter, and not before time I say, you walk outside on a given cold night during the Winter and the smoke from all these Fires, just about suffocate you.
What do you guys reckon?.
Split-system Air Con is getting so efficient these days, it would be criminal NOT to install it!.

My father and I studied 'heat pumps' years ago. They are simply 'reversible' fridges.
I countries like mine (Canada), they would be ideal.
The theory is they can turn cold into heat in the winter, an vice versa, in the summer.
The original installation cost is the main factor.
One system we looked had had underground piping where the temperature doesn't change year round 55F or 15C(?).
The heat/cool energy is free. The only cost is the compressor and fan.

Pinemarten,
Yeah, I have had quite a bit to do with Air Con over the years, in one form or another.
Sure the initial cost of installation is a BIG hurdle, but, these units usually pay for themselves in no time flat and with things like 5-10 year warranty's on things like compressors and fan motors, you really can't go wrong.
As long as you don't expect too much from an AirCon unit, you should never have any problems with it!.
Don't get me wrong, I'm not flying a flag for ANY Air Con companies, I'm just stating things as I see them!.

Air con is starting to appear more and more in Ireland. Almost every small retailer that does a refit of their store seems to install the cassette units into the ceilings. It's great for the two weeks in the middle of summer where the temp. goes over 25C but for the rest of the year it's a bit of a waste of time.

The only places it makes sense here are offices / public buildings where you've a lot of people although in those cases the air conditioning system's main purpose is to provide good ventilation you'll usually find that the system's coolers hardly ever fire up as the air coming is is about 10-17C to start with. They do keep the air changing though which is always a good thing.

This summer was exceptionally warm though and a lot of small portable air conditioners appeared all over the place. You could hire them out for a fairly reasonable weekly fee. Just pop a duct out the window plug into a normal 230V 13A outlet and you had a pleasant environment again.

---

Trumpy:

Coal and other smokey fuels were banned in our urban areas quite a few years ago. I can still remember Dublin with a thick blanket of coal smog hanging in the air it was absolutely disgusting and completely unnecessary. There are plenty of alternative solid fuels that don't create smog.

The policy here was to promote natural gas very heavily there was even tax write offs and grants available to install a gas system to replace solid fuel.

Coal and other smokey fuels were banned from the supply end so they're simply not available anywhere in Ireland.

Pressure Jet oil burners often create particulates too if they're not working correctly. Most of our city councils now require that you have oil fired systems regularly serviced and can check the flue gas for excessive particulates as they can be quite a health hazzard. Again, you'll get a grant if you convert a gasoil pressure jet system to natural gas.
Quite an easy thing to do too, you just replace the burner moduel (almost always bentone or Danfoss)

You just replace something that looks like this:


with something that looks like this:


(basically the same unit with gas control valves rather than a vaporisor nozzle and oil pump)

A typical unit looks like this



A bit of an industrial looking brute compared to what you tend to find in the UK but they last for decades.

You'll usually find these in a small "boiler house" usually located slightly away from the house in the back garden. It normally has a louver door. It normally contains a few circulation pumps and an expansion vessel/pressure vessel. All very industrial looking. These units make a big rumble hence they're located outside

Or:


Modern version of the classic "range"
Typical Gas/Oil range. Heats domestic hot water, 20+ radiators and 2 to 4 ovens and a hotplates. http://www.waterfordstanley.com

expected lifespan is about 150 years


[This message has been edited by djk (edited 10-04-2003).]

djk,
Oddly enough, Danfoss sell Refrigeration and Heat Pump parts over here!.
Yeah, the Gas heater is also a big option over here, but the thing that I don't like like about these heaters is the large amount of condensation that they impart into the rooms where they are operating.
And also the oxygen depletion factor of these heaters, makes them a tad unsafe for my liking.
---
I've serviced the odd Oil-burner, especially the larger ducted type, that are used in a few of our rest-homes here.
They run OK, if the on-site handyman doesn't start mucking around with it, they are rather hard to re-calibrate, to get the mixture just right.
----
On the subject of Air Con gear, the Cassette is quite popular here too in Commercial places and the odd large lounge too.
I've wired more A/C units than I care to think about, but the majority of them have been Hi-Wall units (with the indoor unit mounted at about 1800mm from floor level).
Cheers,
Trumpy.

A/C is becoming more common in light commercial situations, e.g. offices and small shops, but as far as residential is concerned it's extremely rare here.

As for Ireland, most people could not justify the expense for the two weeks in summer when it might be used, although if we keep getting summers like this year's they might reconsider! As is typical in Britain, I think we're still way behind North America and Scandinavia when it comes to heat pumps. Most (non-technical) people I speak to have never heard of them.

Pollution from coal fires was a big problem in British cities years ago, and led to the various Clean Air Acts of the 1950s/60s.

One of the worst smogs occurred in London in the early 1950s:


My parents remembered this one well, and told stories of people stumbling into shops and pubs asking "Where are we?" because they had gotten completely disoriented, even though they were in areas they knew well.

A couple of links:

The London Smog Disaster of 1952

The Great Smog of 1952

Paul,
Not sure if you aware, but Christchurch (just North of here) is the worst place in NZ for smog, it is (at it's worst) 5 times the WHO limits for Air pollution standards, hence the change in heating methods.
Mind you, with the bad Electricity supply security over here(and other places around the world), Air Conditioning is fine, until you have a power cut!.

Trumpy:

Gas burners operating in a room producing heat directly from a flame is pretty rare here these days. It's actually illegal to install open flue natural gas heaters.

95%+ of heating with gas (or oil) here is via either closed (pressurised) or open (head tank), radiator systems.

Ducted systems appeared in the 60s/70s for a very short while and were so problematic and noisy that most people who had them replaced them with radiators.

As for smog reduction. If you ask anyone in Cork or Dublin they would NEVER go back to allowing smokey coal. Londoners would be the same !

As for heat pumps, they're starting to appear in commerical settings but most domestic users would never have heard of them either.

A lot of people also don't realise how mild the weather in most of the UK and Ireland actually is. It's never really extremely cold and it's never really extremely hot either. The rain however is most definitely not a myth!

Winter tempratures tend to sit at around 8-15C with the odd day where it dips into low single figures.

Summer tends to be like 18-28C with the very odd chance of it hiting 30+.

It's colder in Scotland and possibily northern England. (?) but in comparision to even Northern France the British Isles are very mild!

So air conditioning / heatpumps etc are all a bit unnecessary.

A typical central heating system here would be utterly useless in most of the rest of the world. The pipes would more than likely freeze and it wouldn't produce enough heat.

Bear in mind that until the 1960s most houses here had no insulation and central heating was very much an optional extra.

My parents had the heat pump replaced the other week. Taking heat from air to water (underfloor heating, pool). It cost something like $/€5000!

I was at an home improvement fair last sunday. The big thing this year was: Heat pumps, mostly air/air.

All —

In your region, is three-phase power used for residential air conditioning at all? In the US, it used to seem that single-phase hermetic compressors suffered very high electrical-failure rates.

I was under the impression that Heat Pumps didn't really work that well in colder climates. When I worked in Building Maintenance the Heat Pump units didn't seem to be able to do much when it really got cold and thats why we had backup resistance heating elements in them too.

Have they improved that much in the last 20 yrs?

Bill

there have been a lot of heat pumps installed around here lately. They seen to work fine untill the outside temp drops to below 10-15 degrees F or -10 degrees C. Then the supplemental heat strips kick in or the furnace will turn on. The cost is not that much more than a regular condensing unit.

There are pretty strict rules on gas heaters here, most if not all vent into a chimney, so no condensation probs. Stand-alone gas heaters have become pretty rare, they're mostly replacements (but a lot of old ones are still around). The typical heating system for apartments and smaller single-family homes is the wall-mount gas boiler in the kitchen or bathroom that supplies the radiators as well as hot water to bath and kitchen. Larger (and older) single family homes often have larger gas or oil burners located somewhere in the basement (the gas and oil "kettles" as they're called look just like djk's pics). Wood and coal heating is still legal and used, but not widely. Residential air condition is pretty much unknown, and only quite expensive new office buildings have aircon. There's the odd window unit though, they usually get a dedicated 16A circuit or are plugged into the nearest receptacle. Central systems run off 3ph, I've _never_ seen a real heavy load supplied by 1ph here in Vienna (unlike Germany where ranges are sometimes fed with 25A 1ph and 4mm2).
Heat pumps are starting up, but are mostly limited to the eco nuts. I think they're always combined with backup heating, unless they go down deep enough to ensure constant ground temperature.

Like all motors of any size in Scandinavia, heat pumps use 3-ph. Domestic air-cons are an exception since these units are rare and always imported. (They are even rated in BTU or whatever strange unit is used in the US.)

On the efficiency of heat pumps: The one my parents bought is claimed to work down to -18°C / 0°F

[This message has been edited by C-H (edited 10-06-2003).]

I've seen both high ampage 1 phase and 3 phase air conditioners in commercial units here in Ireland. It seems to depend very much on wheather there is a 1 phase or 3 phase supply already installed in the building.

The vast majority of the smaller units are made by Japanese companies... Toshiba & Mitsubishi mostly with some Dalkin units too. (Cassette air conditioners)

The full scale ducted gear would tend to be less likely to come from outside the EU and would obviously be 3 phase.

----

As for gas fired heating systems.
They're generally have what's known as a "balanced flue"

basically the boiler's combustion chamber has no direct contact with the air in the house. Air is sucked in from outside with a fan through a 4" duct. The hot exhaust gas flows out through a smaller duct inside the larger duct.

Air coming in is preheated by the air going out.

It is impossible for carbon monoxide, condensation, or other gasses to escape from the boiler into the room they can only go outside.

Older boilers often had openings for air intakes into the room so if a chimney was blocked or running slow carbon monoxide could have leaked into the room.

----

the big floor standing boilers in the pictures have fans in the burners and are not normally located indoors.

The balanced flue is also the standard arrangement in the U.K. for modern gas/oil heating systems. With the prevelance of modern central-heating, the old stand-alone gas fires are becoming a rarity these days.

The gas geysers that once graced the walls of many kitchens and bathrooms to provide hot water are probably considered archaic by most people now. These things were often open to the room atmosphere, and relied upon proper ventilation to provide suplpy air and exhaust, although sometimes the latter was provided by a chimney-type flue over the appliance. Of course, if the flue got blocked for any reason, the gases would accumulate in the room.

It sounds as though Ireland tried ducted-air heating about the same time period as Britain. Some small apartment blocks from the early 1970s have a kind of central storage heater system with ducts, but piped hot water to radiators is by far the most common modern method.

Ducted warm air is popular in caravans (travel trailers) and motorhomes though.

Indeed. The Gulf Stream keeps our islands relatively temperate, and in a few sheltered areas (e.g. Falmouth in the southwest of England) we even have palm trees growing outside!

What makes up complain about the weather so much here is the rain, wind, and overcast miserable dull days that are so frequent. But most people here just can't imagine the low winter temperatures of central Europe or the American MidWest.

Open geysers used to be very common here, almost every kitchen had them. They've been illegal to install for at least 10 years, I definitely know they were still perfectly legal when my parents wanted to install one around 1988 (but the gas line in the kitchen wasn't...). I guess there are still quite a few of them around. I prefer them to the 5l electric storage heaters as they heat the water much quicker and are more efficient. Modern ones still lok the same but vent into a chimney. Many of them are installed in old houses with drafty windows, so you don't hear of many accidents. In France and Belgium they're still perfectly legal (and it is claimed that this is the reason why these countries have a significantly higher number of CO deaths than for example Germany).

Paul:

Plenty of Palm trees growing happily here on the south coast of Ireland too. Even a few towns with palm tree lined streets! Looks a little weird

Due to an almost complete lack of any type of frost here it's possible to grow a lot of exotic plants without any problem.

According to my atlas, there's a small band which runs around the Cork and Kerry coasts of Ireland, and the coasts of Cornwall and part of Devon in England where the average January temperature is 45 deg. (In the case of western Cornwall, the areas meet to cover the whole far-west of the county.)

The is certainly the mildest winter climate temperature-wise in the islands, though unfortunately it's not the driest! I certainly remember my years living in Cornwall as having very mild winters. It did snow one year though!

Bill,
Yes, I'd tend to agree with you there.
A lot of the larger ducted systems that I've been involved with installing, have needed extra 2-stage heating element banks to supplement the normal heat produced by the compressor.
These banks are nearly always 3 phase units to balance the load over the supply better.
But, like anything, a Ducted Air Con system is only as good as the air temperature sensors that control it and if these aren't installed properly, ie: in the right places, they may as well not be there.
Bjarney,
Over here, the use of 3 phase for domestic A/C is pretty rare, you'd have to be heating a pretty big area to use a Cassette unit in someones lounge.
Having said that, I have wired a unit called a Multi-Head unit made by Mitsubishi and it had 6 indoor units and 1 outdoor unit and all the indoor units communicate with each other and the outdoor unit, it was a wiring nightmare, it was like hooking up a telephone exchange at the outdoor unit!.

Over here you're talking about going 3-phase once the demand goes beyond 63A at 230V.

100A supplies are only installed if the ESB (PoCo) approves them and generally they don't in urban areas as the distribution system is designed around 63A services. If you're in a rural area they might sanction a 100A single phase supply. In an urban area they're more likely to just hook you up to 3-phase and split the load over the phases.

Very easily achieved if the building is wired using radial circuits as you just decide which rooms go on which phase. Ring circuits tend to complicate matters! You're not allowed to have single phase wiring sourced from different phases within the same room. Incase someone somehow connects themselves across 2 phases.

You could have the air con unit sitting on a single phase or 3-phase supply or several small units all on different single phase supplies to split the load. Where 3-phase is used the wiring regulations suddenly become a lot more serious.


[This message has been edited by djk (edited 10-12-2003).]

Similar rules apply in British IEE Regs.

3-phase is rare in residential, but where it is employed in a very large house the regs. specify that all sockets in a room must be on the same phase.

djk,
Over here, we have the standard 63A single phase supply to most of our Residential dwellings.
Where this ends, is for new housing here that ask for a 3 Phase supply of 30A/phase, in that this is to run A/C gear or 3 Phase heating equipment.
Everything in the house is evenly Balanced over the 3 Phases.
Incidentally, you can have a supply out in the country of (3 Phase) 50A, 100A, but you pay more, because you are no longer on the Domestic Supply Rate.
Just as a question, to yourself and Paul, we have the same Regulation over here, about single phase points being on the same Phase within one room.
How on earth could this be a danger?, as it would be pretty rare, if two Phases did contact one another, in a situation like this, can either of you guys give an example of where this has happened?.
We have the situation here, where lighting circuits might be spread over 2 or 3 Phases, but you are required to mark on the sub-plate(of the switch), that there is 400V on the other side of the switch-plate.

As far as I know you can have sockets directly next to each other on different phases if you want. There was something about not mixing 1ph and 3ph wiring though, which would mean you have to run seperate conduits for each single phase and 3ph circuit right from the panel.

The argument is that somebody could end up with two appliances within arms reach of each other on different phases.

If you had two simultaneous faults which left each appliance casing live at 240V to ground, there would be a shock of 415V awaiting anyone who touched both at the same time.

It's always seemed to be a pretty far-fetched scenario to me, but the rule has been there a long time (not sure how long, but it's certainly in the 1955 Regs).

Paul,
Re sockets on different phases in the same room, please see Reg 514-10-01 of BS 7671 : 2001. There is no specific reg prohibiting such an installation, all that is required is a warning notice of the maximum voltage that exists between simultaneously accessible enclosures / equipment, before gaining access to such live parts.

Personally I would consider installing single phase sockets on different phases within the same room to be bad practice, although if the appropriate warning labels are fitted it is in accordance with BS 7671.

I think the actual regulation requiring sockets to be same phase was last in the 14th Edition IEE regs (1966 - 1981). I can't find it in the 15th Edition (1981 - 1991) or 16th Edition / BS7671 present edition.

Trumpy

Over here you get a very over-sized 3 phase system with each phase rated at 63Amps

Certainly won't have any problem powering a few air con units on one anyway

djk,
3 Phases @ 63A a piece?.
That's a HUGE supply!.
I'm guessing that you guys use 3x 16mm2?, to supply this?.
What sized Neutral accompanies this supply?.

David,
I hadn't realized that the rule had been gone so long, so I stand corrected. With 3-ph being so rare in residential work it's not a situation encountered very often.

I no longer have a copy of the 15th edition, but as that's when the regs went to international format and many rules changed, it sounds probable that that's when the requirement was dropped, unless it was an amendment to the 14th during its last years.

By the way, one thing those of you outside the U.K. might not realize is that each edition of the IEE Regs. often has more than one version. David mentioned the 14th edition, in effect 1966 through 1981, but there were running amendments issued, so if someone talks about the "14th edition" it could mean the original 1966 rules, or the amended version of 1968, or the 1970 rewrite into metric units, and so on.

Mike,
For what it's worth, here's the rule as it used to be in the 14th edition:
6 ft. became 2m in the 1970 rewrite.

Trumpy:

There is a smaller 30A 3-phase setup too. However, with 3-phase being relatively rare in domestic installations here it's not seen very often as most 3-phase supplies are for commercial premisis.

However, smaller 3-phase installations on farms and in small commercial installations are becoming much more common place.

3-phase in domestic situations can prove quite expensive to install, particularly if the service is relatively old and underground as there may not be an accessible 3-phase connection point near by. In more remote rural areas it can involve running cables cross-country to the nearest 3-phase connection point which again can cost a lot of money. However, farmers and rural businesses can usually get a government grant to upgrade the supply.

You could be talking €5000 (euro) +...

If you're in an area fed by overhead 3-phase cables it's VERY easy