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  • FIRST POST
    • richardc1983
    • By richardc1983 4th Feb 09, 2:03 AM
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    richardc1983
    Air to Air Heat Pumps/Air Con - Full Info & Guide
    • #1
    • 4th Feb 09, 2:03 AM
    Air to Air Heat Pumps/Air Con - Full Info & Guide 4th Feb 09 at 2:03 AM
    With all the posts ongoing here regarding heat pumps etc I have decided to start a new post I have put together with information on reverse cycle air conditioning (heat pumps), where people can ask questions, chat about heat pumps, discuss experiences, installs, electricity usage & anything else heat pumps related.
    Theres a lot of info here to take in, please do read it all as this may just


    How does it work?

    It's actually quite simple. Air conditioners work in much the same way as your refrigerator except there are two separate, but integral, parts to the system. There is an outside unit housing the compressor that is similar to the exterior back of your fridge. It draws warmth from the outside air in even the coldest of weather. That warmth is then transferred inside the home using a refrigerant process through a piping system powered by an indoor fan unit that is typically mounted to the wall. This is why the system is also often referred to as a heat pump rather then air conditioning. Both are in fact the same. Similarly, in summer, the reverse happens. Warm air is drawn from the interior room and expelled by the outside unit.

    Heat Pumps are capable of transferring up to 4kW of heat into a space while only consuming 1kW of electrical energy. The energy efficiency of a heat pump will decreases as the temperature difference between inside and outside becomes greater, even at low temperatures a heat pump can provide 3 times as much heat as a normal electric space heater would provide with the same amount of electricity input. This makes Heat pumps extremely energy efficient.

    "Not all Heat Pumps are designed to continue working where temperatures fall below freezing point"

    The principle of air conditioning always comes down to the same:

    absorb energy in one place and release it in another place

    The process requires an indoor unit, an outdoor unit and copper piping to connect both. Through the piping the refrigerant flows from one unit to another. It is the refrigerant that absorbs the energy in one unit and releases it in the other.
    Cooling mode (Heating mode is the same but in reverse)

    1 Indoor unit
    A fan blows the hot indoor air over a heat exchanging coil through which cold refrigerant flows. The cold refrigerant absorbs the heat from the air and cooled air is blown into the room.
    2 Copper piping
    The refrigerant circulates through the units and the piping and takes the heat from the indoor unit to the outdoor unit.
    3 Outdoor unit
    Through compression, the refrigerant gas is heated and its boiling point increases. In the outdoor unit the obtained heat throught compression is released to the outdoor air by means of a fan which blows the outdoor air over a heat exchanging coil.
    4 Refrigerant
    The liquid refrigerant flows back to the indoor unit.
    5 Indoor unit
    Back in the indoor unit, the refrigerant is decompressed and thus enabled to extract heat form the indoor air.



    Comparison of 2400w fan heater & Heat Pump Running Costs:

    http://www.bdt.co.nz/comfortmaster/data/guides/WinterRunningCostsComparison.pdf - this is for Mitsubishi Electric but savings made on other manufacters however these will vary.

    Inverter Technology:

    Here's some info about inverters, the same applies across all manufacturers however efficiency levels are different but the operation side of things is the same. There is an article at the bottom from Mitsubishi Electric where they have done a comparison test for a fan heater and heat pump. This is not unique to Mitsubishi Electric, similar costs will be seen across all heat pumps... its a very efficient technology. Different manufacturers will have different efficiencies. The best manufacturers are Mitsubishi Electric, Daikin, Mitsubishi Heavy Industries, Fujitsu, Sanyo, LG, any other manufactures are entry level and will not offer as good quality systems or efficiencies.

    Inverter systems save energy by using a variable controlled Compressor. The output is controlled to only provide the energy required to keep the room to the set temperature. By reducing the output required less power is used and this substantially reduces power consumption. Inverter control not only saves you money but also keeps you more comfortable.


    Inverter System or Fixed Speed System?

    What is a Fixed Speed Split System?

    This system only has a single speed compressor motor that is either on or off.

    It works similar to a fan heater that switches off when the desired temperature is reached and on again when the temperature drops to a set level. It speeds up or slows down to calculate the heat loss from the space to be heated ensuring it is only putting in the same amount of heat that the space is losing.

    What does Inverter Mean?

    Inverter technology uses a variable speed compressor motor similar to a car. It simply slows down and speeds up as needed to hold a selected comfort setting.

    Inverter technology provides a more precise room temperature without the temperature fluctuations of fixed speed systems.

    Inverter vs Fixed Speed:

    Inverter Systems are Approximately 30% more efficient than fixed speed systems.

    Inverter systems reach desired room temperature quicker.

    The speed control of the outdoor unit also means quieter operation, this is important especially at night in residential areas.









    Inverter Systems
    • Increased output to achieve set temperature faster.
    • Then varies the output to maintain a constant room temperature.








    Fixed Speed Type
    • Slowly gets to temperature as output rating is fixed.
    • Then turns on and off to maintain room temperature.
    Sizing of units:

    Read the following guide for sizing info: Excuse the references to Australia and New Zealand this contains useful info:

    http://www.bdt.co.nz/comfortmaster/data/guides/heatpump_sizing_quideline.pdf


    What type of unit is best suited for your property:

    Heat Pumps / Air Conditioners are manufactured with various indoor unit options. High Wall Type, Ceiling Cassette Type, Floor Mounted Type, Concealed Ducted Type, and Under Ceiling Type.


    High Wall-mounted

    The most popular residential unit choice. These units tend to be the quietest as well as taking up no floor space.

    Compact Floor Console

    The floor mounted are more designed for heating applications. They are ideal for space heater or gas fire/fireplace replacement. They can be recess mounted into the wall cavity giving a shallow profile for hallway installation.

    Ceiling Cassette

    The ceiling mounted units take up no floor space. These units have four way air direction and have adjustable air flow patterns. These units are more suited to larger floor areas & commercial properties.

    Ceiling Concealed (Ducted)

    These units are mounted in the ceiling space and are unseen in the conditioned space. The only visible presence is the supply and return air grilles.

    Ceiling Suspended

    These units are more suited to high stud large room areas. They tend to have high airflows and are more suited to commercial applications.

    Multi-Split Systems








    Multiple Indoor Units can be Connected to a Single Outdoor
    • Connect from 2 to 8 Indoor Units
    • Many Combination Patterns to choose
    • Energy Saving and Quiet Operation
    • Five Multi-Split Systems from 6.4kW to 16.0kW (Heating)
    Inverter Multi-Split system models are designed to allow several indoor units (regardless of capacity or type) to be connected to a single outdoor unit. This allows you to select the model best suited to each and every room in your property.


    Example: 3x Bedrooms and 1x Office

    ~


    Location of units:

    Indoors:

    Don’t locate units with obstructions in front.

    Result:


    Short cycling of air back to units room sensor making the unit think its wamer/cooler than it actually is.
    Air is not circulated correctly leaving cold/hot areas in room.

    Try to locate the indoor unit where the airflow is pointing to the other areas of the house that may require residual heating/cooling.

    Outdoors:

    Avoid paved areas unless a drain kit is fitted. Result: Units condensate and drip water. May cause slime build up or ice. If no other place please advise customer.

    Noise:
    Outdoor inverter units are very quiet and have scroll compressors, watch the following video and you will see mine in action:
    http://www.youtube.com/watch?v=-mUzYHEfQEY


    Defrost Cycles & Correct Sizing of Outdoor Unit:
    Defrost will happen in all climates, however the lower the humidity the less frequent it will defrost as it takes longer for it to build up on the outdoor coil.

    You will probably not even notice it defrosting, if you buy a decent brand system you will find that the defrost strategy is very good so that it doesn’t take long to defrost.

    When they defrost you will find that the system goes into reverse, taking heat from the inside circuit to the outdoor unit so it defrosts. This will last about 5 minutes depending on how much ice has built up but you have to look at the unit to notice it doing it as it doesn’t start making things cold inside. The unit just doesn’t heat during that time.

    Some units in New Zealand or other countries that have very cold winters have units optimised for that country, i.e. defrost cycles instead of stopping and going into reverse will inject hot gas into the outdoor unit whilst the unit is heating so that it doesn’t actually stop heating. Currently can only find info on Sanyo air to air heat pumps in this country that do this... not sure of a system that does this on a unit that will provide this on hot water but you can see the technology is there. As I say you don’t need it in the UK climate our winters are not as harsh as some countries.

    The best method for new builds is under floor heating, nice even temps throughout, however longer warm up times due to the lower water temperature but if left on during cold weather you will be fine.

    I personally prefer fan coil units as these double up as cooling/ac for the summer and provide very fast warm up times.

    Most air to water outdoor units can be used with fan coil units... you just use a fan coil instead of a water coil in the floor.

    Mounting of unit... must be installed in the open, no enclosure, so no garages, lofts or corners the unit must be in the open air.

    A user in another post:

    http://forums.moneysavingexpert.com/showthread.html?p=29040015#post29040015

    He installed it in the loft and it froze the loft in the cold weather and thawed and caused leaks into the house below, this happened twice and after this he decided to mount the unit outside and it performed better as it was effectively turning the loft into a giant fridge/freezer.

    Here’s some more info on heat pumps:



    Defrost Strategy

    When the outside temperature drops below zero all heat pumps must perform a “defrost cycle” to remove ice build up on their outdoor coils.

    Defrost strategy is determined by individual Heat Pump manufacturers. These strategies vary greatly between brands. Older style Heat Pumps initiated defrost by a fixed time or coil temperature. This system was not efficient as it often caused Heat Pumps to defrost too often or effected performance by not defrosting often enough. Defrost cycle is required when the outdoor coil is too cold or covered in ice preventing heat transfer and unit performance.

    All Heat Pumps must defrost. heats pumps utilise a Fuzzy Logic software program, a form of Artificial Intelligence contained in the chip of the outdoor unit and typically lasts between 3 to 5 minutes.

    The program measures and records:

    - Ambient Temperature
    - Outdoor Coil Temperature
    - Accumulated Continuous Heating Running Times
    - Defrost Initiation Time and Termination Times

    The program optimises this data based on history to produce defrost initiation only when absolutely required.

    This is important as Heat Pumps are unable to produce heat when they are in defrost mode. This is extremely important to real performance in low ambient conditions.

    Defrost Cycle Management

    Heat Pumps optimise its defrost cycle once selected in three ways:
    When the outside temperature drops below zero all heat pumps must perform a “defrost cycle” to remove ice build up on their outdoor coils.

    Defrost strategy is determined by individual Heat Pump manufacturers. These strategies vary greatly between brands. Older style Heat Pumps initiated defrost by a fixed time or coil temperature. This system was not efficient as it often caused Heat Pumps to defrost too often or effected performance by not defrosting often enough. Defrost cycle is required when the outdoor coil is too cold or covered in ice preventing heat transfer and unit performance.

    The program measures and records:

    - Ambient Temperature
    - Outdoor Coil Temperature
    - Accumulated Continuous Heating Running Times
    - Defrost Initiation Time and Termination Times

    The program optimises this data based on history to produce defrost initiation only when absolutely required.

    This is important as Heat Pumps are unable to produce heat when they are in defrost mode. This is extremely important to real performance in low ambient conditions.



    1. Compressor Control
    When a Heat Pump is defrosting it is not providing heat to the controlled space. It runs the compressor(inverter drive) at maximum speed during defrost to bring the outdoor coil up to temperature as quickly as possible. This melts any ice formed on the coil fins quickly and minimises defrost time. Minimising defrost time maximises heat output per hour real time.

    2. Dry Coil Defrost Cycle
    Once the outdoor coil is up to temperature and the compressor cycle has completed there is generally water between the outside coil fins. If the outdoor unit were to immediately resume heating the outdoor coil would freeze and prevent heat exchange. To prevent this the outdoor fan is run at maximum speed prior to resumption of the heating cycle. This is often characterized by steam blowing from the outdoor unit. This ensures the coil is completely dry before the heating cycle resumes.

    3. Time optimization through Fuzzy Logic
    Time between defrost cycles is continually being reviewed and optimized by the Heat Pump microprocessor software. Algorithmic calculations based on previous history is used to calculate the next defrost period.

    Fuzzy Logic or learning logic is a form of artificial intelligence. Defrost cycle termination is based on a combination of time and temperature. These parameters are used to calculate the next defrost period.

    Outdoor Humidity
    Outdoor humidity also effects heating performance. Areas that have a “dry cold” or low humidity such as “Mount Cook” will perform better at low ambient than say Taupo where ambient conditions can reach zero and “misty” moisture laden air conditions exists. The more moisture in the air the more moisture will freeze on the outdoor coil.

    Incorrect Unit Selection
    If a unit is selected that is too small the Heat Pump will run continuously and never reach set point. This continuous running will increase defrost requirements by reducing the outdoor coil running temperature and driving it into sub zero temperatures for excessive periods. The unit will defrost at the minimum intervals and may never catch up and achieve set point.

    Location of Outdoor Unit
    Location of the outdoor unit is essential for low ambient performance. Units located under houses, decking and in areas where airflow is impeded may create their own microclimate (i.e. giant fridge/freezer or in summer oven) and reduce the effective outdoor ambient temperature that the units operates in. Locating the outdoor unit too close to a wall and not observing clearances will also prevent the unit from delivering full output.


    Get the correct sized unit:
    Choosing the right sized Heat Pump is key to ensuring optimum comfort levels. Every home is as individual as its owner. The key to selecting the right Heat Pump for heating your home is choosing the correct unit size. Choosing the wrong size can cost you more in power consumption.


    Insulation and building orientation are key aspects in terms of potential heat loss a home is effected by. An older style home with poor insulation will lose indoor heat much quicker than a modern well insulated home that faces north.
    The quicker a home loses its heat, the bigger the Heat Pump system will need to overcome this heat loss.
    Last edited by richardc1983; 03-01-2011 at 4:00 PM.
Page 2
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 5:09 PM
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    Andy_WSM
    Andy very good what you have done but all manufacters i know advise the outdoor unit to be installed in open air. For instance most peoples lofts are not big enough to have a unit installed in them. Lofts are draughty but they are not fully open to the outside air. YOu say your loft is always warmer than outside thats crazy... (not that i dont believe you) but I have heard customers have had those self install units and put them in the loft. In heating the loft starts of at 5C but then quickly after about an hour the loft is at -10C and the unit is unable to remove any more heat and over working.

    Lofts are ventilated but not enough airflow for a unit. However you must have a large loft if you have proved the air temp doesnt drop. You may find yoou have to clean your coil more as dust in lofts is quite fine and may clog the coils.
    Originally posted by richardc1983
    It's all there in the manufacturers literature and on their website (units up to 5KW can be mounted indoors or outdoors, bigger units, outdoors only). It's been running up there now for over a week and despite the sub zero nights continues to work very well. The manufacturer recommends this unit for DHW, but other literature suggests it can be used for low level heating and it does this very well.

    Outside right now 8.8C, loft 12.5C, Lounge, 22C.
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 6:55 PM
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    Andy_WSM
    YOu say your loft is always warmer than outside thats crazy... (not that i dont believe you)
    Originally posted by richardc1983
    Had to go away and get the scientific answer as to why a loft is always warmer than the outside air

    Radiative cooling! http://en.wikipedia.org/wiki/Radiational_cooling

    A loft won't be subject to this and will hold a certain amount of heat from the day time in the materials of the build (i.e. the tiles).

    Also, with regards - do I have a big loft?

    Bigger than most houses as I live in a bungalow so am spread out a bit more, rather than living in a box.


    Right now, outside air 8.1C, Loft 9.5C, Lounge 22C.
    • richardc1983
    • By richardc1983 9th Mar 09, 8:12 PM
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    richardc1983
    I understand why a loft is warmer than an outside air, due to heat being lost into the loft from the house below.

    What I am saying is though that working in air conditioning we would never install an outdoor unit inside unless the air supply to the outdoor unit was ducted from outside then ducted back outside.

    The reason being is that once its extracted heat from the loft it then starts to cool the loft even further due to the enclosed space.

    As I have said before I have come across previously units that have been installed in lofts and temperatures have just dropped further and further until the unit tripped out on a fault due to the unit working too hard.

    Have you got a picture of the install or a link to the type of unit you have?
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 8:13 PM
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    Andy_WSM
    I understand why a loft is warmer than an outside air, due to heat being lost into the loft from the house below.

    What I am saying is though that working in air conditioning we would never install an outdoor unit inside unless the air supply to the outdoor unit was ducted from outside then ducted back outside.

    The reason being is that once its extracted heat from the loft it then starts to cool the loft even further due to the enclosed space.

    As I have said before I have come across previously
    Originally posted by richardc1983
    Maybe so, but I live on the coast so it's never likely to get THAT cold here that it is of concern. The other night it was -4C out, the loft got down to -1C. The unit will run to -5C so plenty of lee way there and -4C is very cold for here!

    It's not like the pump runs continuously either. For every 30 minutes it is on it is off for 10, unless I have drained the hot water tank, but again, that would be very rare.

    Richard, what can I tell you - it works!
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 8:15 PM
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    • 4,484 Thanks
    Andy_WSM

    Have you got a picture of the install or a link to the type of unit you have?
    Originally posted by richardc1983
    Here you go: http://www.trianco.co.uk/activair.cfm

    I have the 5KW unit.
    • richardc1983
    • By richardc1983 9th Mar 09, 8:17 PM
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    richardc1983
    Im not saying that it doesnt work, im just saying standard practice is never to install a unit in an enclosed space but if it works and you monitor loft temperature then thats great, im pleased it works for you.

    All i mean is that before I have come across previously units that have been installed in lofts and temperatures have just dropped further and further until the unit tripped out on a fault due to the unit working too hard.

    Have you got a picture of the install or a link to the type of unit you have?

    Your loft must have a very good supply of fresh air for the temperature to not even lower when the unit is switched on.
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 8:23 PM
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    Andy_WSM
    Your loft must have a very good supply of fresh air for the temperature to not even lower when the unit is switched on.
    Originally posted by richardc1983
    It's always windy here (coast again!) so the loft is a bit breezy at times but I only have standard ventilation under the eves and a couple of vent tiles on each side of the roof.

    Next project (when the Government allow it) is a wind turbine to capitalise on the wind and run the heat pump for free.
    • richardc1983
    • By richardc1983 9th Mar 09, 8:34 PM
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    richardc1983
    Have you a link to the unit you have?
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 8:36 PM
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    • 4,484 Thanks
    Andy_WSM
    Have you a link to the unit you have?
    Originally posted by richardc1983
    Yes, I posted it above

    Here you go: http://www.trianco.co.uk/activair.cfm

    I have the 5KW unit.
    Originally posted by Andy_WSM
  • albyota
    Andy, you are obviously very happy with it, I have to agree with Richards concerns RE installed in the loft, but if your happy, thats OK. have you been able to monitor the running costs yet, would be interested to know how much its costing you to heat the bungalow and hot water...what size bungalow? rooms?
    There are three types of people in this world...those that can count ...and those that can't!

    * The Bitterness of Low Quality is Long Remembered after the Sweetness of Low Price is Forgotten!
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 8:53 PM
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    Andy_WSM
    Andy, you are obviously very happy with it, I have to agree with Richards concerns RE installed in the loft, but if your happy, thats OK. have you been able to monitor the running costs yet, would be interested to know how much its costing you to heat the bungalow and hot water...what size bungalow? rooms?
    Originally posted by albyota
    I posted this elsewhere, so to save me posting again, here's a copy & paste. I can't remember if I mentioned that the bungalow is 2 bed and very well insulated (Good insulation is far more important than heating!)

    Simon, my gas boiler packed up a year ago, so I took to using my A/C (Air - Air pump) to heat the house (this had already been installed in the Summer) and whilst it was "OK" I found it drafty at times. The running costs though were better than my gas bills. I used to pay ~ £200 for a Winters gas, but the air-air heat pump only cost £180 to run this Winter and it was a lot colder this Winter than previous years. I was however heating water by electric separately and not monitoring the cost of that.

    However...As I didn't like the drafty heat from the A/C, just over a week ago I purchased an air to water pump and connected it to my old central heating system and water tank. RESULT! Best investment ever! I have posted some details here: http://forums.moneysavingexpert.com/showthread.html?t=1464827

    Summary - I have all radiators on thermostatic valves, The heat pump is set to shut down at 48C (and does so frequently) - room temperatures are set at between 18C & 23C and all are being maintained comfortably. The unit is only 5KW, but the house isn't big and is extremely well insulated, so I don't need a huge amount of heat. Oh, I also leave it on 24/7 so that at no point has it got to work hard to heat the house from cold. I guess if I was only going to run it morning and night I'd need a bigger pump, but I have a chaotic work pattern/life style so 24/7 heat has always suited me best.

    Running costs - first impressions are good. The maximum it has cost in a 24 hour period is £2.20, it was -4C out overnight though. Today has been warmer and it has cost £0.66 for the last 12 hours! These costs include a tank of hot water, which is plumbed in as priority over the heating.

    My Dad is now looking into a heat pump for his property in Devon where there is no gas available. A 3 bed house would probably need the 11KW unit (or bigger) though.

    Hope this helps.
    Originally posted by Andy_WSM
  • albyota
    Yes I understand your enthusiasm, I have an 8.5 kW system, was fitted in oct 08 so have benefitted from very efficient heating and HW even through the coldest of temps -6.7 a few times, and many sub zero days. has performed very well.
    There are three types of people in this world...those that can count ...and those that can't!

    * The Bitterness of Low Quality is Long Remembered after the Sweetness of Low Price is Forgotten!
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 9:09 PM
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    • 4,484 Thanks
    Andy_WSM
    Yes I understand your enthusiasm, I have an 8.5 kW system, was fitted in oct 08 so have benefitted from very efficient heating and HW even through the coldest of temps -6.7 a few times, and many sub zero days. has performed very well.
    Originally posted by albyota
    What size house is your 8.5KW unit heating?

    It will be interesting to see how cheap my hot water is in the Summer. I will set the unit to run for just an hour or two in the middle of the day in the Summer. I am guessing I will be paying pence per day for Hot Water when the outside temps are high?
  • albyota
    four bed Det, approx 200 m2 All UFH & 210 L Cylinder, family of 5 (3 x wasn't me, Teens)
    There are three types of people in this world...those that can count ...and those that can't!

    * The Bitterness of Low Quality is Long Remembered after the Sweetness of Low Price is Forgotten!
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 9:19 PM
    • 2,064 Posts
    • 4,484 Thanks
    Andy_WSM
    four bed Det, approx 200 m2 All UFH & 210 L Cylinder, family of 5 (3 x wasn't me, Teens)
    Originally posted by albyota
    Wow! Makes my 5KW look overkill!

    Very impressive.
  • albyota
    we live in a village, no gas,ripped out 2 yr old oil boiler last sept, installed ASHPB, so total electric now.
    There are three types of people in this world...those that can count ...and those that can't!

    * The Bitterness of Low Quality is Long Remembered after the Sweetness of Low Price is Forgotten!
    • Andy_WSM
    • By Andy_WSM 9th Mar 09, 9:22 PM
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    Andy_WSM
    Have you seen this guy looking for feedback: http://forums.moneysavingexpert.com/showthread.html?t=1544103 ?
  • albyota
    Yes I noticed so here is a previous post I have cut & pasted to save typing again!

    the system I have has developed from a self build I have not quite finished....one day hey..I originally fitted a very efficient oil condensing boiler, which ran very well for two years until the price of oil went up vastly in july / august last year and made the decision to take it out and replace with the ASHP. it was installed at the end of October... I had £700 saved for buying oil as that was the amount we used last winter for aprox 180 days..just for heating and hot water mind... as previously posted my electric bill for nov 6 to jan 25 was for £343...which is for the whole electric useage and roughly £185 of that is for the heating / hot water.. I have meter readings captured daily, and also the outdoor min / max temps.
    There are three types of people in this world...those that can count ...and those that can't!

    * The Bitterness of Low Quality is Long Remembered after the Sweetness of Low Price is Forgotten!
  • samtheman1k
    Andy, I have an ASHP, a 9kW Mitsubishi, and it generates an enormous amount of cold air, is your attic vented/ducted at all? We installed our ASHP in the conservatory temporarily at first, by using the same logic of it normally being warmer than outside, and the temperature in there rapidly dropped below the outside temperature due to all the cold air being generated. I just can't understand how you can put a system who's net air temperature is negative in effectively an almost closed box and not see a temperature drop?
    • richardc1983
    • By richardc1983 10th Mar 09, 1:20 AM
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    richardc1983
    Andy has pointed out that his loft space covers the roof of the bungalow he lives in, it is ventilated the same as any other loft with a couple of roof vents.

    I checked out the link in his post and the manufacturer does state that its suitable to place in a loft as long as there is enough air flow!

    Madness but it seems to be working for him. However im sure not suitable for all applications!
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