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

matelodave

You need a tank to store hot water as the heatpump wont delver hot water like a combi boiler.

My system is pretty conventional - the heatpump makes hot water and a diverter valve either pushes the hot water around the heating system or the into the hot water tank - It's rated at 11kw so cant heat the house and produce hot water simultaneously. My own heat loss calculations for out 140sq.m detached bungalow reckon I need around 10kw.

Every room has a programmable thermostat which controls the heating loop in the room and controls the system circulating pump so the heat pump probably doesn't have to heat every room all at the same time unless we let the house get very cold when it can take a day or more to get the place back up to temperature. The flow temperature is controlled by the weather compensation function which measures the external temperature and adjust the flow temp to between 30 and 40 degrees depending on the outside temperature.

We don't turn the heating off, just down a couple of degrees overnight and back up again before we get up. Each room has it's own programme according to use but non are set below 17 degrees.So at this time of year if it's everso cold it will kick in and out all night as required.

The 200l hotwater tank is timed for two hours before the heating is time to start and we only heat it to 45 degrees. This gives us sufficient hot water for all our daily needs (including a shower each). There is a boost to 60 degrees to sterilise the tank once a week.

Jeanners49

Hi Richard, you very kindly commented on my original post some months ago. I'm sure you sent me a private message about getting someone from LG to look at it, but I can't find the message now. We did manage to find someone local to look at the heat pump and it has been properly set up. He is supposed to be writing us a report so we can take legal action, but I've yet to hear back from him.
Anyway, I just wanted to thank you for your help and advice.
All the best,
Jean

Kernel_Sanders

DD137 wrote: »

I'd like to take a radiator off the wall to paint behind it for example but have no idea how to refill / pressurize the system after reconnecting it

You can paint all visible areas of the wall with paint applicators designed for the purpose.

mrmmhf

Winter performance of our air source heat pump - would value your feedback and comments, and see it compares to you systems.

https://youtu.be/XaZ2CmXUp-g

pensionpawn

Hi there. I have solar panels that produce ~ 6.3Mwhrs pa, electric UFH in all ground floor rooms except the lounge, which we'll do in the next couple of years, and have gas CH / HW. The house is 24 years old and well insulated (although the windows need replacing) however I do need to replace my ageing boiler and h/w tank. The panels produce enough spare electricity to supply hot water, with only the exceptional need for gas (late night showers, thunder storms all day), from late April to early October. During this time it grates with me that I pay a 27p daily standing charge for hardly any use. So, thinking about how much it would cost me to replace the boiler and tank, I started to look into ASHP's especially having typed my details into the RHI website and was told that I would receive £6k5 over 7 years to offset the cost. Now my annual gas bill is between £500 - £600 a year and I know that the ASHP saving against gas is marginal. However, and this is the rub, what I am looking for is a variant of an ASHP that will not only drive air to water (to run the CH / HW Oct - Apr) and qualify for the RHI but ALSO, in the same / combined unit, drive air to air. Why? Because my house becomes very warm (with the heating off) during the summer, sometimes making sleeping difficult, and I've seen A/C working in a similar sized house, and A/C is just an air - air ASHP running in reverse. What I'm hoping to find is an ASHP system that will give CH & HW as well as cool A/C in the summer. There would appear to be many common components which in a combined system should be cheaper (and less hardware space intensive) than installing A/C in a separate parallel installation to a air to water ASHP. So, in conclusion, has anyone seen anything like what I am looking for? The closest I have seen so far is a Samsung TDM system, however that drives a wet UFH system and I have dry (electric). Thanks in advance.

matelodave

You could use a fan convector or fan coil unit to provide cool or warm air instead of a conventional radiator or underfloor hot water system. https://www.installeronline.co.uk/fan-convectors-underused-alternative-rads-ufh/

If you pump hot water through it it will produce warm air and if the water is chilled then it will be cold. You may need to check the specific requirements of the RHI as it doesn't cover an air-air system but might be OK for an air-water (even though the emitters are fan coil units). 

I guess if the system is configured correctly then it will be able to produce hot water for the tank and chilled water for the fan coils but probably not simultaneously. (my heat pump cant heat the hot water and u/f at the same time - there's a diverter valve)

Rodders53

Three pipe heat pump systems are able to heat and cool different indoor units - VRF/VRV systems.  Whether those can qualify for RHI is another question.
But to get RHI, pensionpawn will need to employ a registered installer, who can answer all those questions during the specification/quotation phase?
Cold water in a fan-convector emitter will need consideration of how to deal with the condensate that will be formed in summer cooling mode.

pensionpawn

So, essentially, the water is heated, as it would to supply a radiator, and then the energy is convected, rather than radiated, into the room? There are also efficiencies in working with the lower temperatures from an ASHP. How does the cost compare for these fan convectors compared to buying new radiators matched to a traditional ASHP installation? My other concern is how effective they would be at cooling a room down compared to a dedicated A/C system. I appreciate that the fan aspect is similar to a fan on a dedicated A/C system however a coolant process is required (which is built into an A/C solution). UFH is electric and water can be heated through the IH (via PV in summer) if necessary on occasion so I don't see an issue the ASHP trying to heat water and cool the house at the same time. To be honest, an ASHP would no be doing must in the summer as the house is hot enough and solar provides most of the hot water.

pensionpawn

Does anyone know who supplies the lowest E7 rate? The best I've found is Bulb at 8.1p. With a battery an ASHP could run through the winter at the lowest E7 rate available. The day rate doesn't matter (as much) to me as in the summer my import would be zero and a Powerwall can timeshift to put a massive dent in winter electric costs. So if I do the sums with a COP of 3 and compare against a gas tariff of 3p then the numbers look good. Paying for a battery is madness just to justify an ASHP however it would also be used to financially enable moving to an EV, eliminating import from March to November and boosting (import free most of the year) max power availability to ~ 10kWs.

Pulpdiction

Anyone had a heat pump installed and recommend their provider?  Looking in the midlands/Warwickshire area

Thanks