Cyprus-Forum.com

[coredump]

We do not heat air with this kind of heating but we heat up objects

Does not microwave oven work the similar way? Is it safe for health? Do you have any Goverment/EU issued safety certificates?

[chrisn]

Microwaves are electromagnetic waves with wavelengths longer than those of the far infrared light emitted from the Lexin screens and therefore have another frequency and energy level.

Extensive independent research underpins all our products and have confirmed the public safety for all of the Lexin heating screens. (EU en US certificates). We also have an independent scientific research report saying that Lexin infrared heat has no detrimental effects on the human body.

In fact, people in the Benelux and Germany are using this kind of heating for medical (health) reasons. People who are suffering from rheumatism and asthma and therefore are very sensitive to air circulation and relative air humidity are using Lexin screens because it offers them relief by keeping air conditions homogenous and reducing the muscular pain.

[rokos]

Sounds like a wunderful heating system!
Is it possible to use this in a wet envirement like a bathroom?

[devil]

The cost of operation (electricity costs) for this house on Cyprus would be CYP 110 the whole year.

Sounds very good.

Sounds far too good to be true with typical uninsulated Cypriot construction. Can you please substantiate this figure, showing your calculations? £110 will buy you typically, at today's prices, about 1,300 kWh. Say you need heating over three months, that is 450 kWh/month or 15 kWh/day. I presume, fot a modern house of the size you indicate, you will need 3 x 2 kW panels in the bedrooms, 2 x 1 kW panels in the bathrooms, a 2 kW panel in the kitchen, and 4 kW in the living/dining room, totalling 14 kW of panels, each of which would be switched on for 1 h and 4 minutes, on an average, per day. This does not ring true.

OK, let me make another comparison: I have a 3 bed modern house and we use storage heaters which run on cheap tariff, as opposed to your radiant heaters which must use the full tariff. We certainly do not overheat the house, preferring an extra sweater, 19-20°C being typical. These heaters are on a separate 3-phase meter so we know EXACTLY how much we pay for heating and that was £532.14 last winter, which was not exactly a hard one. and it has averaged over £500 for the last 4 years. We are budgeting for £750 this coming winter (increased fuel costs on EAC invoices). Last winter, we paid an average of £0.0302/kWh on the cheap tariff and £0.0716/kWh on full tariff. Had we been invoiced on full tariff for our heating, we would have paid £1,216.63 to heat the house, which is slightly smaller than your 140 m².

Therefore, to pay only £110/year would be little short of a miracle, unless you heat only to 5-10°C. And, before you try to pull wool over my eyes, let me warn you I'm a Chartered Electrical Engineer, so I do know what I am talking about. So please don't waffle on about the difference between radiant and convection heating. To heat the mass of a house and its contents to a given temp with a given heat loss requires a fixed amount of energy, no matter what it is converted from.

As there are some other blatant errors in what you write, can I assume only that you have little or no scientific/technical knowledge, or have you forgotten all you learnt?

Devil (C.Eng., MIEE)

[cyprusgrump]

The cost of operation (electricity costs) for this house on Cyprus would be CYP 110 the whole year.

Sounds very good.

Sounds far too good to be true with typical uninsulated Cypriot construction. Can you please substantiate this figure, showing your calculations? £110 will buy you typically, at today's prices, about 1,300 kWh. Say you need heating over three months, that is 450 kWh/month or 15 kWh/day. I presume, fot a modern house of the size you indicate, you will need 3 x 2 kW panels in the bedrooms, 2 x 1 kW panels in the bathrooms, a 2 kW panel in the kitchen, and 4 kW in the living/dining room, totalling 14 kW of panels, each of which would be switched on for 1 h and 4 minutes, on an average, per day. This does not ring true.

OK, let me make another comparison: I have a 3 bed modern house and we use storage heaters which run on cheap tariff, as opposed to your radiant heaters which must use the full tariff. We certainly do not overheat the house, preferring an extra sweater, 19-20°C being typical. These heaters are on a separate 3-phase meter so we know EXACTLY how much we pay for heating and that was £532.14 last winter, which was not exactly a hard one. and it has averaged over £500 for the last 4 years. We are budgeting for £750 this coming winter (increased fuel costs on EAC invoices). Last winter, we paid an average of £0.0302/kWh on the cheap tariff and £0.0716/kWh on full tariff. Had we been invoiced on full tariff for our heating, we would have paid £1,216.63 to heat the house, which is slightly smaller than your 140 m².

Therefore, to pay only £110/year would be little short of a miracle, unless you heat only to 5-10°C. And, before you try to pull wool over my eyes, let me warn you I'm a Chartered Electrical Engineer, so I do know what I am talking about. So please don't waffle on about the difference between radiant and convection heating. To heat the mass of a house and its contents to a given temp with a given heat loss requires a fixed amount of energy, no matter what it is converted from.

As there are some other blatant errors in what you write, can I assume only that you have little or no scientific/technical knowledge, or have you forgotten all you learnt?

Devil (C.Eng., MIEE)

I’m delighted that somebody else thinks the same was as me!

Even if the ‘miracle system’ only heated humans as is claimed, it would still need to be switched on all the time and radiating heat into the room.

[chrisn]

It’s excellent for bathrooms.

First you feel always colder in a bathroom, because the Lexin Heating System can be controlled for each room separately, you can put the thermostat for the bathroom a little bit higher and feel comfortable any time you come out of your bed or out from the shower.

Second, with this system installed the development of mould and mildew is virtually impossible because moisture condensation cannot occur.
Because moisture condensation in winter times in every Mediterranean country is a problem (especially at nights in bedrooms) people feel definitely better with this system.

[cyprusgrump]

But if you don’t heat the structure of the house (just the people in it), surely moist air from showers, baths, etc. will be more likely to condense than with a traditional system?

[chrisn]

Our maximum panel which measures 120x60 cm is 1 Kilowatt and is enough to heat up an entire room of 20 to 25 square meters, our smallest one is 0,5 KW
Linked to a control and a room thermostat this screen will only consume 40 to 60% of its installed capacity when heat is needed, so not continuously the 24/7.

So let’s take for an example the house of about 140 square meters and assume we need 7 KW.
Degree days allow us to calculate your estimated energy consumption.
Keep in mind however that it is a mere estimate as it is subject to variables that can influence your consumption both in a positive and a negative way.

The calculation is based on the average day temperature measured by different national weather stations. A degree day calculation assumes that when the outside temperature is higher or equals to 18°C we do not need heating.

The number of degree days in one day equals 18°C, this is the average day temperature and equals 0 when the average day temperature is higher or equals to 18°C. So when the average day temperature is 17°C we have one degree day, when it’s 16°C we have two degree days on one day.
Degree days link the external temperature to your energy consumption but do not take other weather influences like wind and sunrays into account.
To compensate we multiply degree days with a weight coefficient depending on the season.

Cyprus has less than 900 degree days.

The formula to estimate our costs: Energy Consumption in Kwh = Installed capacity in KW x Degree Days / 3,125.
In the case of the 7 KW: 900 x 7/3,125 equals 2016 KW
This 2016 KW have to be multiplied by the actual costs of KW ( I calculated with 5 cents per KW) in Cyprus and than for sure ad 10% because it’s an estimate.
This formula is developed by our engineers and independent test underpins these figures in test for periods for more than a year.

In the case for the house of Devil I guarantee that with this system we will not exceed 110 CYP a year if the installed KW is less than 7 KW. I even will make a free installation at his house and if we exceed the CYP 110 with more than 10% he can keep the installation for free and I even will pay him the difference in energy costs. If we not exceed CYP 110 he will pay the system. These figures are based on KW of 5 cents and a normal winter period, I mean no freezing nights of minus 10 degrees Celsius, etc.

The calculation is based on temperatures of 20 to 22 degrees for the living room and kitchen, 18 degrees for the bedroom and 24 degrees for the bathroom.

Isolation is not so important as with convection heating, the Lexin system heats up the walls of your house and they will act as a natural isolation.
I maybe do not have as much scientific/technical knowledge as people of this forum but my figures are based on experience and on many, many installations over here in the Benelux and Germany.

Challenge me.

[cyprusgrump]

I do hope Devil takes up your challenge!

I’m a little confused though – in your first post you said: -

In October this year I will introduce the Lexin Central Heating system in Cyprus.

Whereas in your last post you said: -

my figures are based on experience and on many, many installations over here in the Benelux and Germany.

I’m not a heating engineer (I have a background in electronics) but I can see certain flaws in your arguments.

Your calculations are based on the ‘average day temperature’ and assume that if it is 18 degrees or higher you will need no heating.

The problem in Cyprus is that the day temperature may well be above 18 but the night temperature in winter is much lower. None of the houses are insulated so during winter you quickly get to a position where the concrete skeleton of the house cools down substantially and it often feels colder inside your house than outside droning the day. While it might be 18 or more outside you still need the C/H on inside to remain comfortable.

Also, after a short while in Cyprus you acclimatise to the heat and find you need your heating system set much warmer than you would in the UK to feel comfortable.

Having spent three winters here and experimented with different heating systems (we rented two apartments while our house was being built) I just can’t see how 7KW, however efficient it is could heat the average Cypriot home through a long, cold wet winter.

[devil]

Your calculations may be an approximation for houses built to European standards, but here you are in Cyprus, where houses have only minimal insulation. If you look at http://www.ibpsa.org/PDFs/BS03%2520Pape ... 39_346.pdf
the average house is exemplified in case A. You will see that the heating requirements are MUCH higher than you pretend.

In any case, the misleading degree-day notion is not exactly brilliant. The average figure for Nicosia is 964, but you don't wish to calculate heating on a mean, but on a 98 percentile worse-case scenario. That is to say that you must maintain temperatures within the comfort zone for 98% of the time. Therefore you should calculate for mean minima, which are typically 5°C lower than the average. This would almost double your degree-days, without allowing for extreme lows (the minimum recorded at Athalassa was -5.0°C).

Furthermore, where your degree-days notion falls down is that heat losses through brick are time-dependent. If you have 19 cm of brick with one side at, say, a constant 20°C and the other side falling to 5°C, the temperture gradient within the brick is not linear but asymptotic. A probe at 9.5 cm depth will record a slowly falling temperature until equilibrium is reached, at which time the heat losses will be maximal because you will have a larger gradient over a shorter distance. I would say that the time constant for a typical brick as used in this country would be about 5 hours.

Then you calculate the kWh at 5 cents. The average, when heating is done, with the progressive tariff is currently more like 8 c with VAT and renewables tax added and will quite likely reach 10 c in the near future, as all electricity on this island is generated from oil.

I will not take you up on your offer, which is plain stupid, because I have no wish to take advantage of your folly. If you make many such offers, you will drive yourself into bankruptcy, believe me. Perhaps you don't even realise that my house is at an altitude of 310 m, so we are typically 2°C colder than Nicosia in winter. We reckon on about 20 nights with ground frosts and 5 nights with air frosts per year. In Nicosia, there are an average of 2.2 nights per year with air frost.

I'm sorry, but please come down to earth and stop promising miracles: they won't happen.