Discussion ... ASHP(Air/Air) with Solar pv ....

zeupater

ASavvyBuyer wrote: »

Not been much discussion about this recently, despite the heatwave!
However, we are so pleased we had the heatpump/air conditioner installed.
It is working a treat keeping the house at a steady 24 degrees C, despite it being 30+ degrees C outside.
Also, it is hardly using any power to keep us cool and all coming from the Solar PV.

Hi

Ours was used a few times when the hot weather first arrived, but we're becoming more acclimatised so although it's been getting even warmer outside, we've not been using it for some time ... If we'd been having shorter hot spells with cooler spells in between we'd definitely be using it more!

HTH
Z

zeupater

Dave_Fowler wrote: »

We're just back from a holiday in the nice cool weather in Scotland to find the house is in the upper 30s and low 40s for most of the day - even with all the windows and doors open. Hot water fully heated, car fully charged and still lots of spare power.

What's involved in installing an air-con unit in the conservatory to cool the house in the summer and provide some heat in the autumn & spring? Is this a DIY install or do I need a specialist? How does one decide on a specification, particularly when hoping to use the PV system for most of its power supply?

Dave F

Hi Dave

Don't know how well you're insulated, but in most hot countries I've been to it's normal to keep everything closed up to keep the heat out during the day then open one or more upstairs windows as soon as it's cooler outside than inside in order to dump heat overnight, then close up again in the morning ... rinse, repeat & you can keep the property reasonably cool ... that's what we tend to do.

As mentioned in the last post, we've not been using the heat-pump for cooling recently because we've simply become more used to the higher than normal internal temperatures ... if it's flip-flopping between hot & cooler days then the system would definitely be on more!

As ASB mentions, have a look through the thread for info/ideas & check the specs on the units we have, the published performance data seems to be pretty accurate & you'll get an idea of sizes involved.

Any questions, just ask, but I think that we've all been pleased with our units so far ...

HTH
Z

Martyn1981

ASavvyBuyer wrote: »

Not been much discussion about this recently, despite the heatwave!
However, we are so pleased we had the heatpump/air conditioner installed.
It is working a treat keeping the house at a steady 24 degrees C, despite it being 30+ degrees C outside.
Also, it is hardly using any power to keep us cool and all coming from the Solar PV.

Ours has pretty much been running flat for a month from about 8am to 8pm.

The Cardiff Bowl (that traps heat) has been hot, hot, hot.

Martyn1981

Dave_Fowler wrote: »

We're just back from a holiday in the nice cool weather in Scotland to find the house is in the upper 30s and low 40s for most of the day - even with all the windows and doors open. Hot water fully heated, car fully charged and still lots of spare power.

What's involved in installing an air-con unit in the conservatory to cool the house in the summer and provide some heat in the autumn & spring? Is this a DIY install or do I need a specialist? How does one decide on a specification, particularly when hoping to use the PV system for most of its power supply?

Dave F

Hiya Dave, you can get DIY units that are pre-pressurised, but I understand that the professionally installed units are a bit more efficient.

Small units start at about £400-£500 and go up with size and features and efficiency. Installers I used charge ~£500.

My conservatory is just a glorified mini extension with a glass and UPVC front wall, and a DG roof. All glass is currently covered in insulated and reflective blinds and the 3.5kW HP can just about cope on the hottest days here (25C-30C in the shade).

If you have a 'proper' conservatory, with more glass, then you'll need more power to fight back, or need to install the unit in the living room, and shut off the conservatory.

Heat wise, not a problem, the 3.5kW can cope fine for us, heating the tiny conservatory (2.4m by 2.4m by 2.4m) very quickly, and the living room, and door wide open to hallway for boost to rest of house.

Dave_Fowler

Martyn1981 wrote: »

Hiya Dave, you can get DIY units that are pre-pressurised, but I understand that the professionally installed units are a bit more efficient.

Small units start at about £400-£500 and go up with size and features and efficiency. Installers I used charge ~£500.

My conservatory is just a glorified mini extension with a glass and UPVC front wall, and a DG roof. All glass is currently covered in insulated and reflective blinds and the 3.5kW HP can just about cope on the hottest days here (25C-30C in the shade).

If you have a 'proper' conservatory, with more glass, then you'll need more power to fight back, or need to install the unit in the living room, and shut off the conservatory.

Heat wise, not a problem, the 3.5kW can cope fine for us, heating the tiny conservatory (2.4m by 2.4m by 2.4m) very quickly, and the living room, and door wide open to hallway for boost to rest of house.

I too have been looking at the 3.5kW system. Although the 2.5kW would be big enough for a normal room the size of the conservatory, all the advice give has been to go for the larger size in a conservatory. I'm not looking to have the conservatory cooled down to 20C or anything like that, but just enough to keep the temperature down to something reasonable.

The conservatory is acting like an open oven. We accidentally left the doors to the lounge closed the other week and found the temperature in the conservatory had risen to 58C. Most of the house plants in there died. At the moment at 10:15am the outside temperature is 25C, the conservatory (all windows open to let in the cooler air) is 35.6C and the lounge 28.7C. As a matter of interest the loft temperature is 26C and the PV panels 44.7C.

I've contacted two installation firms so far for quotes. Both said there would probably be a 4 week delay before a possible install because of the recent demand.

Dave F

Zarch

My lunch hour has just consisted of reading all 12 pages of this thread. :rotfl:

A couple of questions.

Is there any sort of device, a bit like what a iBoost does that will allow the ASHP to only come on and run when there is excess PV available? Some sort of generation detector? So usage is always 'free'?

From what i'm reading there seems to be a bit of manual intervention checking you're generating and switching the ASHP on when the sun comes out?

We have a 3 storey house, would one unit make any sort of impact? The top floor is a loft conversion bedroom that is boiling in summer and needs the most heating in the winter.

Dave_Fowler

Zarch wrote: »

My lunch hour has just consisted of reading all 12 pages of this thread. :rotfl:

A couple of questions.

Is there any sort of device, a bit like what a iBoost does that will allow the ASHP to only come on and run when there is excess PV available? Some sort of generation detector? So usage is always 'free'?

From what i'm reading there seems to be a bit of manual intervention checking you're generating and switching the ASHP on when the sun comes out?

We have a 3 storey house, would one unit make any sort of impact? The top floor is a loft conversion bedroom that is boiling in summer and needs the most heating in the winter.

Most A/C units recover from a power cut, so it would be possible to switch on and off the unit remotely when there is sufficient / insufficient power. But it can't be done proportionally like an immersion heater controller. The circuit I'm using to control the charging of my EV would work - a thought that hadn't crossed my mind before.


Dave F

gefnew

Hi all
I have a sma inverter that as a separate contact that will divert to an additional device eg battery.
regards
gefnew

gefnew

Hi All
What is the best facing aspect to install ashp unit with regards the best cop of the unit.

zeupater

gefnew wrote: »

Hi All
What is the best facing aspect to install ashp unit with regards the best cop of the unit.

Hi

I thought of this some time ago with respect to positioning the outdoor unit on/near a wall that had the best solar irradiance, but in the end decided that due to the unit airflow any potential gain would effectively be negligible for when we planned to use the system ...

In reality if looking to provide heating in cold periods with relatively high humidity there's a logical argument that a south facing outdoor unit would need to enter the defrost cycle (slightly) less often, but for us it was far more important to have the indoor unit where we wanted it & keep the pipe runs reasonably short to reduce circuit inefficiencies (heat gain/loss) which is far more relevant, so it's on a roughly NW facing wall.

HTH
Z