UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

Alexojus

Hi everyone,
We have just realised our pressure is pretty high, is it a problem? It is currently at 3 bar but used to be a normal 1.5/2 bar. We don't know if it's related but when the beast from the east came, we had an error U1 which was due to the fan outside being completely frozen. As soon as we defrosted it, it started again. If it's a problem how can we lower it. We know there is a handle somewhere to lower the pressure but not sure which one.
Thanks a lot for your help.

SaraR2018

In short, air to air heat pumps operate under the same principle the air conditioners do, the only difference, and a decisive one, is that the former function the other way around in comparison to the latter. The air source heat pumps extract the heat from the outside masses of air and transfer it to the pump’s indoor unit compressor. This process is entirely based on the principle of heat transfer, which is supported by the pump’s refrigerant property to lower the temperature of the air that is passed through the device. Thus, the thermal value of the incoming air is below the ambient temperature level, which leads to the thermal isolation of the air heat.

Advantages of an air to air heat pump

Air to air heat pumps are universal in terms of providing heating during the cold season and air cooling during the hot days of the summer.

Low installation costs. There is no need to drill boreholes or use expensive equipment in order to install an air to air heat pump.

These pumps possess a significant heat transfer capacity.

There is no need to install complex heat distribution systems, like radiators or underfloor heating.

The ease of use is ensured by autonomous climate control thermostats, that automatically monitor the pump’s functioning parameters.

The pump’s overall costs (installation and operational costs) shall not exceed the levels a person with an average income would be comfortable with.

The pump’s background noise is insignificant and thus does not represent an annoyance factor for people who will find themselves in the same room with the pump’s indoor unit.

Air to air heat pumps have no impact on the room’s indoor climate.

Heating your property by means of an air source heat pump is environmentally friendly. The heat pump does not release any harmful gases or components into the atmosphere.

matelodave

Of course an air-air heatpump has an impact on the room's indoor climate.

It makes it warmer when heating and cooler when cooling and will dehumidify the air when cooling because water will condense on the indoor unit - that's what they do.

They are air conditioners even though they may be called heatpumps when they are used in the heating mode.

Are you trying to sell them???

ian103

weve been thinking of an air to air heat pump,weve had a quote, it all seems too good to be true, they say we will save money on our heating.



perhaps were being too negative but we have storage heaters which are at best ok, wecould renew these as we understand how they work etc,



we need to review our electric supplier and it looks like we are facing substantial increases.


are air to air a viable option and can anyone recommend am advice website?

richardc1983

If you have mains gas get that.

If you don't then an air to air or air to water is the way to go and is the cheapest form of electrical heating out there due to how the heat is produced.

For advice read the beginning of this topic.

ian103

Thanks for the reply, no mains gas in the area.


At present we have economy 7, other houses use oil which we dont like.


Air to water would be major work and more expensive but we would get an goverment incentive.


Air to air would possibly suit as we generally keep doors open etc, I guess our problemis getting our head around the way air to air works and the economies ofsuch a system.


Research on the web still says modern storage heaters are the cheapest form of heating, the company that quoted the system suggest otherwise.



If the systems are so good why arent they more common?

richardc1983

Ok so an air to air works like your fridge freezer In that it moves heat from one place (outside air) to another (inside air). Air to water is the same except the heat is transferred to the water circuit inside instead of inside air.

They are efficient as you are using a inverter compressor which is an electrical motor. This pumps refrigerant around which changes from liquid to gas under different states it is this the causes the heat to be transferred from one place to another.

There are no electrical elements hence why they are so efficient. Some videos below some are to water but the principle is the same. Having air to air you'll have air con in the summer. In the winter it just reverses the flow of refrigerant. You can get summer cooling from air to water using fan coils but this is a more expensive set up having air to water anyway.

https://youtu.be/HsFFJTB16N0

https://youtu.be/G53tTKoakcY

ian103

Is there a realistic way to assess the running costs of the system,the supplier we contacted goes very very vague when asked, the house is occupied 24 hours a day so the heating will be on all the tme, its in an exposed location and we its draughy due to the exposed nature of the property. (this is what is causing the concern with storage heaters).


We have a very good tarriff at present that comes to an end in January so looking around our bill will vastly increase as our night rates will increase by circa 3p a unit and the day rate by 6p a unit making it not very economic, so a single rate may suit?

richardc1983

Single rate if it's on 24/7 I can't advise in running costs as dependant on many factors.

zeupater

ian103 wrote: »

Is there a realistic way to assess the running costs of the system,the supplier we contacted goes very very vague when asked, the house is occupied 24 hours a day so the heating will be on all the tme, its in an exposed location and we its draughy due to the exposed nature of the property. (this is what is causing the concern with storage heaters).


We have a very good tarriff at present that comes to an end in January so looking around our bill will vastly increase as our night rates will increase by circa 3p a unit and the day rate by 6p a unit making it not very economic, so a single rate may suit?

Hi

If you have storage heaters and these provide the majority of your heat (apart from occasional electric fire/fan-heater heating?) as well as heating your DHW overnight you could simply(!) estimate the cost of the heating.

(1) - In the summer there shouldn't much (/any) heating required, so overnight usage would be limited to DHW & baseload (fridge etc) ... if you look at the historical billed difference in daily E7 usage (kWh) between summer & winter then that'd give an idea of the energy used for heating ...

(2) - The heat-pump will have a seasonal performance efficiency figure hidden somewhere in the specs (SCOP) ... all you'd need to do is use the estimated usage (kWh) from (1) and divide it by the SCOP and you'll have an idea of the relative heating energy requirement.

(3) - Unlike storage heating, the heat-pump will need to consume daytime energy as well as E7 so you'll really need to guess at your heating pattern .. only you know how comfortable you want to be and how much effort you put into your own usage efficiency. Obviously, running the system in the day costs more that at night, so if you think that you'll be providing 50% of the daily heat requirement overnight (to pre-charge the property's thermal mass) and 50% during the day then calculate an average heating energy unit cost (£/kWh) halfway between daytime & E7 rates ...

(4) - Multiply (1) by the E7 unit cost & multiply (2) by whatever you calculate in (3) ... that'll give a rough comparison idea (£/heating day) of what you're looking for ....

Depending on how you use the system, it may make sense to move away from E7 to access a lower (single) daytime rate and change the heating pattern ... but again that's down to preference & the thermal performance of the property.

HTH
Z