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

Ally74

richardc1983 wrote: »

As per cardew these happen regularly when it's cold... My own system goes into defrost every 4 hours of compressor run time if its not that cold and this is known as oil recovery mode and will allow oil in te pipework to return to the compressor. When it is going into defrost is there actually frost on the coil outdoor?

My system doesn't tend to do genuine defrosts until outside temps go below 4c.

I would need to check that but don't know where the coil is placed or what it looks like?

Misti Ecodan 8.5kw

richardc1983

Ally74 wrote: »

I would need to check that but don't know where the coil is placed or what it looks like?

Misti Ecodan 8.5kw

The outdoor unit is where you ened to be looking... this will be mounted outside somewhere.

The coil is the large coil (looks like a car radiator) on the back of the outdoor unit).

Is your unit heating well or are you cold? How often in an evening is it going into defrost?

Ally74

richardc1983 wrote: »

The outdoor unit is where you ened to be looking... this will be mounted outside somewhere.

The coil is the large coil (looks like a car radiator) on the back of the outdoor unit).

Is your unit heating well or are you cold? How often in an evening is it going into defrost?

Thanks Richard

I went out to locate the coil today and see it behind the fan. I will check it when the temps drop again. It went into defrost mode yesterday evening again, only the once that i noticed though.

The other week when the temps dropped a bit further it was going into defrost mode almost every hour which i thought was odd because it wasn't that cold compared to what it's going to get soon. As the temps drop further will it defrost more frequently than once an hour?

It's heating well. Seven rads with a temp flow of 40C which is the target i set for it.

richardc1983

Ally74 wrote: »

Thanks Richard

I went out to locate the coil today and see it behind the fan. I will check it when the temps drop again. It went into defrost mode yesterday evening again, only the once that i noticed though.

The other week when the temps dropped a bit further it was going into defrost mode almost every hour which i thought was odd because it wasn't that cold compared to what it's going to get soon. As the temps drop further will it defrost more frequently than once an hour?

It's heating well. Seven rads with a temp flow of 40C which is the target i set for it.

At these ambients it should not be going into defrost at all really. My system at these ambients every 4 hours does an oil return cyle which due to be an air con system runs the system in defrost (cooling mode) to push an oil from the pipework and indoor fan coil units back to the compressor. Not sure if you system has refrigerant lines running to the inside or if it is just water pipes but if there is then your system can be expected to do a similar thing (that will be observed as defrost on the display) THe frequency of oil return though is like I say once every 4 hours or so.

When it is much colder i.e freezing my system generally runs a defrost cycle every couple of hours this is when ice has built up on the rear of the unit (ice is not normally seen on the side of the coil facing the fan) if I am running the system under high load eg below 0C outside and all rooms demanding heat then defrost could run once per hour.

Defrost cycles running at these ambients at all really could indicate the system being short of refrigerant or other issues that you need to address now before winter really sets in.

You need to observe if ice is on the back of the coil when it goes into defrost.

Ally74

Thanks Richard i will keep an eye on the defrost cycles as the temps drop again. I'm afraid i can't see the coil from behind the fan as there is an aqua blue mesh around the back and side and it's very difficult to see through.

If it does seem to be defrosting too often again then i will update and call the installers.

pd001

albyota wrote: »

Edale, same as me 31 units a day, £2.85, we have an alternative to a tumble drier, get Mrs Edale a dehumidifier for the clothes drying, pulls 300 watts per hour, 2 hours and the clothes are dry, it sucks 2 litres of water straight out into a tank, use the condense water in the iron or on the plants.

Just bought a dehumidifier to perform this very task..drying clothes.
Didnt realise that the water it produced would be ok for the iron and I have just instructed Mrs pd001 accordingly.
As you may imagine, she wasn't convinced.

2 hours, dry clothes? Got to be a result if it works

richardc1983

Ally74 wrote: »

Thanks Richard i will keep an eye on the defrost cycles as the temps drop again. I'm afraid i can't see the coil from behind the fan as there is an aqua blue mesh around the back and side and it's very difficult to see through.

If it does seem to be defrosting too often again then i will update and call the installers.

A mesh around the coil? Or around the unit?

Ally74

Around the unit. Just inside the outer casing.

richardc1983

Ally74 wrote: »

Around the unit. Just inside the outer casing.

I have heard of people removing that as it has been known to cause ice build up.

albyota

Ally74 wrote: »

Thanks Richard i will keep an eye on the defrost cycles as the temps drop again. I'm afraid i can't see the coil from behind the fan as there is an aqua blue mesh around the back and side and it's very difficult to see through.

If it does seem to be defrosting too often again then i will update and call the installers.

Hi Ally74, the aqua blue finned mesh you describe IS the coil. That is what the refrigerant gas circulates through, it is a long continuous pipe, the fins are where ice would build up and therefore need to defrost, when a defrost cycle occurs, the refrigerant gas from the compressor flows in reverse, hot gas flows through this pipe to melt off the ice.