Air Source Heat Pumps

samtheman1k

Andy_WSM wrote: »

Stats from here: http://www1.conrad-uk.com/

There are 3 on the site: Part number 616100-LN these are the ones I have @ £29.95ea

615952-LN @ £34.95
560606-LN @ £39.99

The coldest it has been here since I have had the heat pump is -7C and it continued to work, although ran continuously, so won't have been particularly efficient I wouldn't have thought.

Hello Andy,

can you give us details on your individual programmable room thermostats? This is something I've been toying with for a while, but the only way I can find to do it is to get individual thermostats for each room with a valve...just seems a bit messy, rather than a single house programmer with individual actuators/valves??

Andy_WSM

samtheman1k wrote: »

Hello Andy,

can you give us details on your individual programmable room thermostats? This is something I've been toying with for a while, but the only way I can find to do it is to get individual thermostats for each room with a valve...just seems a bit messy, rather than a single house programmer with individual actuators/valves??

http://www.andyworth.co.uk/wp-content/uploads/2009/08/616100-an-01-ml-Funk_Energiespar_Regler_de_en_fr_nl.pdf

That's a link to the PDF of the instruction manual.

I have 4 of these thermostats. Fitting them was a simple case of removing the old wax cylinder adjustable thermostats and replacing with these instead. They mean I can have different rooms heated to different levels depending on time of day. No point keeping the bedroom wall all day for example, likewise, no point heating the lounge at night.

richardc1983

Andy_WSM wrote: »

The key to my system - and I have said this before, is that I run it at low temperature (45C) ALL THE TIME. Yes, the insulation is good, loft insulated to 9", walls insulated and polystyrene beneath the tiles floors, but it's still a detatched house.

I never resized the radiators, at all. Gas boiler out, ASHP in.

It's below -6C here now and I'll hold my hand up and say the system is on it's knees right now - I have heard it defrost twice in the last hour and the temps inside are not up to usual. In fact, my hot water is only at 39C this morning so I'll have to pop the immersion on for half an hour before I can shower. In all fairness though, I never spec'd the system for such cold conditions living on the SW coast. We can go entire winters without a sub zero temperature.

I've had to put the gas fire on in the living room too for extra heat this morning, something I rarely HAVE to do, but do like the comfort glow some evenings!

Still, despite one or two days a year when the system doesn't give me everything I need of it, my low heating bills and 24/7 warmth more than make it all good.

Great stuff Andy, as you say the few days that we do have these temps you can pop your gas fire on and have that cosy glow.

Whatever you do dont switch that off at all... not that you would otherwise you would lose the fight!

richardc1983

Andy_WSM wrote: »

http://www.andyworth.co.uk/wp-content/uploads/2009/08/616100-an-01-ml-Funk_Energiespar_Regler_de_en_fr_nl.pdf

That's a link to the PDF of the instruction manual.

I have 4 of these thermostats. Fitting them was a simple case of removing the old wax cylinder adjustable thermostats and replacing with these instead. They mean I can have different rooms heated to different levels depending on time of day. No point keeping the bedroom wall all day for example, likewise, no point heating the lounge at night.

How much did these cost you?

Andy_WSM

richardc1983 wrote: »

Great stuff Andy, as you say the few days that we do have these temps you can pop your gas fire on and have that cosy glow.

Whatever you do dont switch that off at all... not that you would otherwise you would lose the fight!

It's still on & fully recovered. Outside temp is 3C and the unit has reached set point and turned off several times this afternoon. No harm done to the system at all. Guess they are very good at self preservation at times like that. So long as ice build up on the unit doesn't prevent the fan turning it can look after itself.

Andy_WSM

richardc1983 wrote: »

How much did these cost you?

£29.95 inc VAT each.

richardc1983

Yeh the ice wouldnt form on the fan as if you look at it when it is iced up the ice cannot be seen on the inside of the unit only on the back of the coil where the air enters.

Forgot to ask you again, what set point do you have is it 21 or 22?

Ours is 22C during the day and usually 23C on a night if we are cosying down in front of the tv.

Last night we hit 23C with -3 outside, good stuff.

Andy_WSM

richardc1983 wrote: »

Yeh the ice wouldnt form on the fan as if you look at it when it is iced up the ice cannot be seen on the inside of the unit only on the back of the coil where the air enters.

Forgot to ask you again, what set point do you have is it 21 or 22?

Ours is 22C during the day and usually 23C on a night if we are cosying down in front of the tv.

Last night we hit 23C with -3 outside, good stuff.

The set point is 45C on my unit, but the radiators are all either set at 21 or 22C. It wasn't able to achieve those temps this morning though and fell short by a few degrees.

I think it was ok down to -3C, that's the temp when I went to bed last night, but must have got behind in the night when the temps fell even further.

It probably won't get that cold again this Winter!

richardc1983

Andy_WSM wrote: »

It probably won't get that cold again this Winter!

I woudnt be that sure... its forecasted for this for the next week or so, up here temps during the day next week of -2!!!

You say the flow temp of the rads is 45C whats the highest it can be? Obviously if it was struggling this morning if you set it to higher its not going to achieve that but perhaps now you could bump it up if you needed to?

Andy_WSM

It won't get that cold down here again They are once in 10 year temps - and they've happened twice this year already LOL.

The heat pump will run anything from 35C to 55C. I wouldn't want to turn it up higher than 45C, the house is plenty warm enough now, to the point that most rads have shut down and all I'll do is mess with the efficiency and maybe even cause the unit to ice up sooner if I give it more to do?

It's only the 2nd time in the last year that it has failed to cope, when I consider how many times my gas boiler broke down and how long I would be without heating and hot water every time it did