Ait to air heat pump/aircon

[David]

I'm considering installing (having installed) some air conditioning to
cool the house on the few (but getting less rare) days when the air
temperature is around 30C or more.
Although anything above 26C can be uncomfortable.

I don't think I need to cool the whole house.
The minimum would be a North facing downstairs front room which is
currently the coolest in the summer.
However I am wondering about cooling the core of the house (hall, stairs,
landing) as well to give a larger area of comfort zone which is not
exposed to much thermal gain.

Has anyone done this?

I have read the 2017 Wiki article which was very useful but not really
relevant to my case as it was a self install where the two part system was
relatively close.

It did, however raise a question.

Installing on a roof - does this mean a flat roof, pitched roof, what? I
would have thought an install on a flat roof garage or extension would be
very sensible.

My favoured ease of install option would to be to install on the upstairs
rear of the house and run coolant pipes to the landing and front bedroom
(North facing) through the loft.

This would cool the core of the house and a bedroom and might overspill
into the downstairs North facing room.

An alternative would be to install at ground level in the car port
(minimise neighbour noise) and have one cooling unit in the downstairs
front room then run coolant up the side of the house and into the loft
space to one or more coolers in the upstairs.

Whatever, I don't see an easy way of having a heat exchanger and cooling
unit back to back through a wall apart from the rear bedroom, but then the
heat exchanger would be pointing at my neighbour's house in clear air and
so could be a noise problem.

Any advice and/or personal experience most welcome.

Cheers



Dave R


--
AMD FX-6300 in GA-990X-Gaming SLI-CF running Windows 7 Pro x64

[The Natural Philosopher]

On 22/02/2023 15:12, David wrote:
> I'm considering installing (having installed) some air conditioning to
> cool the house on the few (but getting less rare) days when the air
> temperature is around 30C or more.
> Although anything above 26C can be uncomfortable.
>
> I don't think I need to cool the whole house.
> The minimum would be a North facing downstairs front room which is
> currently the coolest in the summer.
> However I am wondering about cooling the core of the house (hall, stairs,
> landing) as well to give a larger area of comfort zone which is not
> exposed to much thermal gain.
>
> Has anyone done this?
>

Friend of mine has. The living room is single brick, south west facing
and takes time to get warm and too hot in summer, so he stuck something
on the wall outside that blows hot and cold inside.
He is well pleased with it.

> I have read the 2017 Wiki article which was very useful but not really
> relevant to my case as it was a self install where the two part system was
> relatively close.
>
> It did, however raise a question.
>
> Installing on a roof - does this mean a flat roof, pitched roof, what? I
> would have thought an install on a flat roof garage or extension would be
> very sensible.
>
> My favoured ease of install option would to be to install on the upstairs
> rear of the house and run coolant pipes to the landing and front bedroom
> (North facing) through the loft.
>
> This would cool the core of the house and a bedroom and might overspill
> into the downstairs North facing room.
>
> An alternative would be to install at ground level in the car port
> (minimise neighbour noise) and have one cooling unit in the downstairs
> front room then run coolant up the side of the house and into the loft
> space to one or more coolers in the upstairs.
>
> Whatever, I don't see an easy way of having a heat exchanger and cooling
> unit back to back through a wall apart from the rear bedroom, but then the
> heat exchanger would be pointing at my neighbour's house in clear air and
> so could be a noise problem.
>

Ah. Ny friends unit is precisely what you cant implement, Bugger.
I suspect that your preferred solution will not be a 'drill ten holes
and bugger off' but a few days of custom work, and very expensive.

The only good news I can offer is that it should work. if you can
implement it.

> Any advice and/or personal experience most welcome.
>
> Cheers
>
>
>
> Dave R
>
>

--

"When one man dies it's a tragedy. When thousands die it's statistics."

Josef Stalin

[Theo]

David <wib...@btinternet.com> wrote:
> Has anyone done this?

No, but looking at air2water cooling.

> Installing on a roof - does this mean a flat roof, pitched roof, what? I
> would have thought an install on a flat roof garage or extension would be
> very sensible.

Beware that that may require planning permission, especially if pitched or
you're raising the height of the building. Outbuildings are typically
single storey because that's permitted development, where putting an aircon
unit on the roof would blow through the maximum height budget.

> Whatever, I don't see an easy way of having a heat exchanger and cooling
> unit back to back through a wall apart from the rear bedroom, but then the
> heat exchanger would be pointing at my neighbour's house in clear air and
> so could be a noise problem.

There is no strict need to have the units back to back - just think about
what happens in commercial premises (although the larger buildings pump
around chilled water not refrigerant).

However the 'easy install' units are pregassed and there is only enough gas
for a certain length of pipe - check the installation manual for how much
that is. If going beyond that length it'll need more gas, but that should
be straightforward for an F-gas installer to do, which they would have to do
anyway for a regular (non-'easy') unit. There may be a certain maximum
amount of gas in the system the unit can cope with - check the manual.

OTOH the longer the pipe run the more losses you get from it (even
insulated), so you lose a bit of efficiency when doing so. Also, you will
need to arrange a condensate drain from the indoor unit: do you have any
convenient wastewater pipework, or can you drain it outside? There are
condensate pumps so it doesn't strictly need to be downhill, although the
pumps make a noise and are another moving part to maintain.

Theo

[SteveW]

On 22/02/2023 20:08, Theo wrote:
> David <wib...@btinternet.com> wrote:
>> Has anyone done this?
>
> No, but looking at air2water cooling.
>
>> Installing on a roof - does this mean a flat roof, pitched roof, what? I
>> would have thought an install on a flat roof garage or extension would be
>> very sensible.
>
> Beware that that may require planning permission, especially if pitched or
> you're raising the height of the building. Outbuildings are typically
> single storey because that's permitted development, where putting an aircon
> unit on the roof would blow through the maximum height budget.
>
>> Whatever, I don't see an easy way of having a heat exchanger and cooling
>> unit back to back through a wall apart from the rear bedroom, but then the
>> heat exchanger would be pointing at my neighbour's house in clear air and
>> so could be a noise problem.
>
> There is no strict need to have the units back to back - just think about
> what happens in commercial premises (although the larger buildings pump
> around chilled water not refrigerant).
>
> However the 'easy install' units are pregassed and there is only enough gas
> for a certain length of pipe - check the installation manual for how much
> that is. If going beyond that length it'll need more gas, but that should
> be straightforward for an F-gas installer to do, which they would have to do
> anyway for a regular (non-'easy') unit. There may be a certain maximum
> amount of gas in the system the unit can cope with - check the manual.

Some manufacturers apparently sell pre-gassed, self-seal, extension pipes.

[John J]

I have a 2.5kW Mitsubishi split system. The inside unit is on the landing, with the inverter drive outdoor unit wall mounted on brackets at waist height for convenience of access. The sound levels are insignificant and only really noticeable when standing alongside the outdoor unit on full power. It has cooling function which is the reason I wanted it, plus the bonus of heating. It was a godsend during the exceptionally hot days last summer. The connecting pipes (1x1/4" and 1x3/8" plus 20mm condensate drain) and cables pass through one hole in the wall then down to the outside unit and a drain point. The condensate is handy for filling the steam iron.

[Theo]

SteveW <st...@walker-family.me.uk> wrote:
> Some manufacturers apparently sell pre-gassed, self-seal, extension pipes.

I'd have thought it would be better to have a continuous, pressure-tight
(brazed/soldered?), pipe run, rather than an assortment of self-seal joints
which will eventually fail. It doesn't really complicate the install very
much (if the installer has the kit, which they should) and makes for a more
robust, longer lasting, job.

Theo

[SteveW]

The pre-gassed ones were designed for DIY installation or by general
builders, with no requirement for special kit or knowledge.

[The Natural Philosopher]

On 23/02/2023 10:32, Theo wrote:

You had better tell the plumbers and building regs that. O-ring self
sealed joints have been standard for over 20 years on plastic pipes
under pressure


--
"And if the blind lead the blind, both shall fall into the ditch".

Gospel of St. Mathew 15:14