Air source heat pump advice air to air Panasonic

anco

Hi all
I have just moved to Scotland and the heating is Panasonic air source heat pump air air to air on a THTC tariff. The house is fully electric and am terrified of the costs. I have had conflicting advice on the settings for it and hoped for some advice to maximise the warmth and the £ efficiency. 
1. Is it best for both to leave it on all the time? I only turn it on when I am in the house. I turn it off overnight too.
2. I have it set at 20-22 degrees but it seems to blow cold air out not warm. Is that normal?
3. Everything else is set at heat and auto (fan, speed etc)
It just doesn't seem that warm after gas central heating and the cold air blowing drives me to use the halogen heater.
Thanks in advance for your help!

matelodave

I'm guessing that a THTC tariff is not ideal for a heating system that generally uses energy whilst it's in use, rather than a storage heater which stores heat during the off-peak periods and delivers it.during peak periods.

Generally an air-air system is an "on-demand" heater, ie you turn it on when you want heat (a bit like a fan heater) and down a bit to keep the chill of the place. So an off-peak supply just doesn't synchronise with it. As it heats air rather than the fabric of the building it should be fairly responsive but the place will get cold very quickly when it's off.

An air-to-air heat pump should blow out warm if not hot air when it's operating in heating mode and cold air when it's in cooling mode, so there's either something wrong or you haven't got it set up correctly.

Personally I'd get myself onto the cheapest single rate energy tariff I could unless you can derive real benefit from E7 by using as much off-peak energy as possible by heating the hot water, washing, drying and other stuff during the night.

Tiexen

anco said:

Hi all
I have just moved to Scotland and the heating is Panasonic air source heat pump air air to air on a THTC tariff. The house is fully electric and am terrified of the costs. I have had conflicting advice on the settings for it and hoped for some advice to maximise the warmth and the £ efficiency. 
1. Is it best for both to leave it on all the time? I only turn it on when I am in the house. I turn it off overnight too.
2. I have it set at 20-22 degrees but it seems to blow cold air out not warm. Is that normal?
3. Everything else is set at heat and auto (fan, speed etc)
It just doesn't seem that warm after gas central heating and the cold air blowing drives me to use the halogen heater.
Thanks in advance for your help!

I have a Mitsubishi air source heat pump it puts out plenty of heat as to cost it should be the same as gas and much cheaper than your halogen heater

For every 1 kWh of electricity, an air source heat pump can produce 3kWh of heat.

macman

Have you spoken to or contacted the previous owner for advice on how to set the system up?
Based on what you have told us, THTC with air source makes no sense at all, as you won't be using it on cheap rate for 7 of the 10 available hours. I suspect the GSHP air to air system has been installed to replace NSH's on E10, but for some absurd reason the metering was never changed to single rate.You probably need to get the installer in to review the whole set up.
PS: if you just leave it blowing in cold air, then it should come as no surprise that the house feels cold...

matelodave

macman said:

Have you spoken to or contacted the previous owner for advice on how to set the system up?
Based on what you have told us, THTC with air source makes no sense at all, as you won't be using it on cheap rate for 7 of the 10 available hours. I suspect the GSHP air to air system has been installed to replace NSH's on E10, but for some absurd reason the metering was never changed to single rate.You probably need to get the installer in to review the whole set up.
PS: if you just leave it blowing in cold air, then it should come as no surprise that the house feels cold...

A GSHP (Ground Source Heat Hump) is not an air to air system as it's source is via heating loops under the ground. An ASHP is an Air Soruce Heat Pump where the source is derived from the air (usually outside but sometimes internally - using heat recovery).
An air-to-air system provides blown hot or cold air via air handling units fed directly from the refrigerant whereas an air to water system transfers the heat or cold to water which is then fed around to the emitters whether they be fan coil units, radiators or underfloor.

However in any case a THTC or other off-peak supply isn't generally suited to a heatpump system unless you only use it during the off-peak period as they need to run continuously during the times that you require heating (or cooling) and air-air systems would be the worst in that respect. Their advantage is that they are more responsive and usually have a better COP but dont heat the fabric of the building like either GSHP or air-water ASHP

Rodders53

Exact model of indoor and outdoor units would help determine precisely what is installed in this home.

My Fujitsu LUCA split pack air to air units sit and 'idle' for 3-4 minutes before they start to blow warm / hot air around (aimed at the floor), and that 'delay' is mentioned in the handbook/manuals. 

For these to blow cool to cold air on the heat setting suggests they are not working as designed and may need a service / re-gas?

Was a bit chilly in the Kitchen earlier this morning and within 15-20 minutes we were toasty and my Kitchen is not small, 21C set so we reduced that to 20C then switched it off a few minutes later when we'd finished breakfast.  (That one is a nominal 5.4 kW heating unit, 4.2 kW cooling).
We seldom have the fan set on auto whether heating or cooling and it's usually at minimum speed unless being used 'in anger' to warm or cool the room (as we did earlier, but only for part of the time it was on).