Air Source Heat Pumps

Andy_WSM

Swipe wrote: »

Wow, sorry to hear that Andy. If I were you I'd move it outside, that can't be good for your roof. I've also been getting condensation in the loft during this cold spell on the days that there is no wind. I plan to install more vents.

Ah, good point. So the loft has been suffering condensation, probably due to the very still air on these cold nights, so insufficient ventilation - then the ASHP has caused any condensation to freeze, making the problem worse as moisture condenses on cold surfaces. Looks like I had a bit of a vicious circle going on up there.

I've just ordered up a suitably sized wall bracket - which hopefully will arrive before the weekend when I will enlist the help of a friend to move the unit to outdoors.

richardc1983

Andy_WSM wrote: »

Ah, good point. So the loft has been suffering condensation, probably due to the very still air on these cold nights, so insufficient ventilation - then the ASHP has caused any condensation to freeze, making the problem worse as moisture condenses on cold surfaces. Looks like I had a bit of a vicious circle going on up there.

I've just ordered up a suitably sized wall bracket - which hopefully will arrive before the weekend when I will enlist the help of a friend to move the unit to outdoors.

I hate to say it Andy but I do remember a while ago I said the unit should be outside in readily available fresh air... let this be a lesson to anyone that plans to install one in any sort of enclosed space be it a garage or a loft or basement.

THese units need to be in the outdoor air where the air changes are constantly being replenished.

The problem with these units is that in winter they are kicking out very cold air and this will lower the loft temp to very very low levels, well below freezing.

This is why you are having these problems and the condensate will then continue to freeze, your trianco unit will then struggle with such low temps in the loft to heat the house, it may only be -5C outside but in the loft could be hitting -15C your unit will be producing hardly any heat.

My LG unit is mounted on the floor outside... it had a build up of ice on the floor in front where water was running across the floor when it drained away but it wasnt building up inside the unit etc it was fine.

I chucked a bit of grit down on the ice and it has kept cleared since.

You are doing the best thing by clearing it out.

Perhaps to take some of the moisture out the air, turn the heat pump back on for a bit heat the house up and leave the fan heater in there so some heat is in the loft area, the cold wet coil will be taking moisture out of the air so the loft will dry out quicker and the fan heater will stop things from freezing.

It will run like a dehumidifier.

richardc1983

Andy_WSM wrote: »

Spot on here. I have been working away today and came home to a lovely warm house this evening. 1C outside, 21C inside. All radiators piping hot. I have heard the unit defrost once tonight, but that is to be expected. Electricity used today by heating just over £1.25 so far. Won't cost any more than £1.50-£2 for the days heat & hot water, even in weather as cold as it is now.

1C outside but your loft was probably at -5 possibly even lower.

Your unit would have loved the 1C temps outside and been able to extract a lot of heat your unit wouldnt have been on its @rse as you said a couple of times lol!

richardc1983

Andy_WSM wrote: »

Sorry Richard, I had already crashed out by the time you replied! No, I don't adjust mine. I leave alone. It has run through the night happily. Well below freezing here now with gale force winds (-3C, Wind chill taking it to -12C), but still 21C indoors. the ASHP has used a grand total of 60pence worth of electricity through the night.

-3C outside possibly -12C in your loft!!!

Your unit again is probably suitable to work down to -10C with very little loss of performance!

You will notice the diff when you get it outside.

Andy_WSM

richardc1983 wrote: »

I hate to say it Andy but I do remember a while ago I said the unit should be outside in readily available fresh air...

You did, but I DID install it as per the manufacturers recommendations. I said at the time I'd see how it works - and it worked perfectly for a year, right up to these colder than usual weeks we have had (incidentally, looking like the Coldest December in over 20 years when the final figures are in).

With regards temps in the loft - It was -3C out last night and -6.3 in the loft!

It only ever manages to drag the loft temps down to a few degrees below outside air temps - that said, we haven't seen many days recently where the temps have gone more than a couple of degrees above freezing, which I am sure is why I have this problem now.

Andy_WSM

richardc1983 wrote: »

You are doing the best thing by clearing it out.

Perhaps to take some of the moisture out the air, turn the heat pump back on for a bit heat the house up and leave the fan heater in there so some heat is in the loft area, the cold wet coil will be taking moisture out of the air so the loft will dry out quicker and the fan heater will stop things from freezing.

It will run like a dehumidifier.

I have done just this. The fan heater is on low drying the insulation and keeping the frost off the condensate drain and I have removed the loft hatch to help the air move around to dry the place out.

I was horrified at what a mess had been made in what can only have been a week or so.

Still, live & learn. I never really wanted the unit on the back wall, as being in a bungalow it's going to stick out like a sore thumb - I am going to put it above the kitchen window so at least it won't be in the way. I have little spare floor space in the direct vicinity of the bungalow - plenty of garden, but I don't want the losses associated with long pipe runs!

richardc1983

When the condensate runs off the unit in defrost mode it is always warm water as the coils are warm so the condensate should be able to drain away until it hits something really cold such as a floor and then freeze.

I cant believe the manufacturers still think this is the best way, I wonder if you could get in touch with them and have them change the install guidelines based on your experience because im sure this has happened to many other people before.

THe loft temp might only be 3C below the outdoor air temp but that 3C the unit isnt going to be working as hard as its warmer.

I would have loved to have seen some pictures of the loft? Did you manage to get any in the panic?

Andy_WSM

richardc1983 wrote: »

When the condensate runs off the unit in defrost mode it is always warm water as the coils are warm so the condensate should be able to drain away until it hits something really cold such as a floor and then freeze.

I cant believe the manufacturers still think this is the best way, I wonder if you could get in touch with them and have them change the install guidelines based on your experience because im sure this has happened to many other people before.

THe loft temp might only be 3C below the outdoor air temp but that 3C the unit isnt going to be working as hard as its warmer.

I would have loved to have seen some pictures of the loft? Did you manage to get any in the panic?

No pics, it wasn't really the first thing on my mind! LOL

The drain pipe ran across the loft floor and down through the eves into the gutter - so you can imagine this whole pipe was well below freezing! I can't think of any way (other than heating the pipe with say, electric heating wire?) of keeping this drain able to run in these sort of temperatures?

richardc1983

Possibly but you might as well just move it to the outside in case the wire ever failed or anything else went wrong.

You could serioulsy damage your loft if it happens again etc.

Simplest way is to just move it outside then you dont have to worry about frozen pipes etc.

greendwarf

Swipe wrote: »

Wow, sorry to hear that Andy. If I were you I'd move it outside, that can't be good for your roof. I've also been getting condensation in the loft during this cold spell on the days that there is no wind. I plan to install more vents.

Although Andy's is an extreme case I worry about condensation a lot. I always understood that when you put in loft insulation you would need to ensure adequate ventilation to avoid condensation - no one ever mentions this now! I suspect a real problem with rotten rafters in the future but heh, who cares if we've reduced our carbon footprint in the meantime.

I've just spent £2,500 to get new gutters, soffits and ventilators BEFORE I upgrade the insulation with 100mm top up glass fibre between the joists and 30mm Kingspan under the rafters.