Wind from ASHP on the neighbor's door - barrier?

[Garald]

The heat-pump from Mitsubishi has been installed - and guess what: the contractor tells me that noise is a non-issue. Hurray for Mitsubishi Ecodan Silence!

 

... but the wind from the machine (which would be very cold in the worst of winter) will blow right in the face of some of the neighbors as they go out of their front door. (Yes, this was the least bad place to put it.) I don't think Paris regulators remembered to forbid this (they just set strict noise limits), but obviously I don't want to be an arse.

 

How to solve this?

 

It would seem simpler, cheaper, more aesthetic and probably also more effective to set up some sort of solid fence or barrier (possibly homemade) rather than a sound-reducing capsule (which is meant for a different problem, is expensive, might decrease efficiency by a not completely trivial amount, and may not change the direction of the "wind" at all).

 

Is this right? 

 

If so, at what distance should it be so as not to interfere with the operation?

 

 

 

 

PS. Answers to my previous question are also appreciated:

 

[SteamyTea]

Wait until there is a real problem, i.e. neighbours complaining.

 

Then build a screen around it.

[Garald]

Well, I'd rather do it now that the workers and the architect are still around!

 

Also, one side would be enough, wouldn't it be? What's the minimal distance so as not to interfere with anything? Does the material matter?

[ProDave]

I assume the open door in the picture is yours?

 

Rotate the ASHP 90 degrees so it blows along the passage not across it.  It would blow the cold air past your front door not your neighbours.

 

Putting screens in front of them is very bad, on another thread recently someone posted a you tube clip of an experiment to box one in, and it ended up recirculating it's own air and choking itself.

[DanDee]

12 minutes ago, Garald said:

Well, I'd rather do it now that the workers and the architect are still around!

 

Also, one side would be enough, wouldn't it be? What's the minimal distance so as not to interfere with anything? Does the material matter?

 

If I were you, I would go back to sleep and dream for a top fan heat pump, check RED heat pumps.

Edited March 22, 2023 by DanDee

[Garald]

27 minutes ago, ProDave said:

Putting screens in front of them is very bad, on another thread recently someone posted a you tube clip of an experiment to box one in, and it ended up recirculating it's own air and choking itself.

 

Is there a distance starting at which the effect is slight? 1m?

 

Not to repeat myself, but I am talking about putting a screen *in front* of it, not *around* it.

Edited March 22, 2023 by Garald

[SteamyTea]

34 minutes ago, Garald said:

Is there a distance starting at which the effect is slight? 1m?

The energy is wind is proportional to the cube of the windspeed (I think, how wind turbine yield is calculated)

[Garald]

5 minutes ago, SteamyTea said:

The energy is wind is proportional to the cube of the windspeed (I think, how wind turbine yield is calculated)

... so? The point being that we have to be very careful not to diminish the windspeed? I agree of course, but what would be a good distance?

[ReedRichards]

I've stood in front of my heat pump, which is probably a bit larger than yours, but never found the "wind" it makes to be particularly strong, nothing compared to the actual wind on a breezy day like today.

[SteamyTea]

1 minute ago, Garald said:

.. so? The point being that we have to be very careful not to diminish the windspeed? I agree of course, but what would be a good distance?

The point is that you will not feel it once 1.5 m away.

You could go out and find one that is running and see what it is like.

At the college I was at, they had some huge units to heat and cool the library.  We all used to stand by them and smoke.  I can't remember every feeling a breeze from one of them, unless I put my hand by the grill.

 

[JohnMo]

If you install a screen, do angled (say 45 deg) vertical slats to turn the flow down the passageway, or horizontally to throw the air upwards.

Edited March 22, 2023 by JohnMo
Spelling

[Garald]

What about the ideas given here? Good or bad?

 

https://www.decoclim.fr/content/27-comment-cacher-sa-pompe-a-chaleur-idees-solutions-conseils-et-diy

[Garald]

(And yes, the door and all the windows you see in the picture (including the one that hasn't been set yet) are all mine.)

[ProDave]

This is the you tube vid about guys deliberately boxing in a heat pump and watching the air flow with a smoke candle.

 

 

[Garald]

But the result shown in the video is that a fence doesn't bring efficiency down perceptibly, even though one can see smoke recirculating!

[Garald]

But how can efficiency be affected as *little* as they show once the unit is covered up?

[ProDave]

7 minutes ago, Garald said:

But the result shown in the video is that a fence doesn't bring efficiency down perceptibly, even though one can see smoke recirculating!

I suspect what it will do, is at temperatures close to the dew point, is increase icing up as the recirculated air will be colder, and increase defrosting frequency, and hence reduce efficiency that way.

 

I still favour rotating the unit 90 degrees so the cold air gets blown past your door not across to your neigbour.

[Garald]

17 minutes ago, ProDave said:

I still favour rotating the unit 90 degrees so the cold air gets blown past your door not across to your neigbour.

 

Right, this seems so evident that I wonder why it wasn't done. I was trying to get to my head contractor today, without success. Of course he'll hate me when I suggest this, since apparently he stayed up until 9:30pm working on this with the heat-pump installer (that's a late hour for non-academics, or so I am told).

[Dave Jones]

mount it higher up on the wall.

[saveasteading]

18 minutes ago, Dave Jones said:

mount it higher up on the wall

Genius.

Allow plenty of isolation to stop it rattling the walls.

[SteamyTea]

On 22/03/2023 at 20:51, Garald said:

apparently he stayed up until 9:30pm working on this with the heat-pump installer (that's a late hour for non-academics, or so I am told).

Tell him if he works hard he can retire at age 64.

[Garald]

Just talked to the contractor directly. (I was getting his comments filtered through the architect, who has some sort of instinctive anti-heat-pump biased, besides almost messing things up majorly, as you may recall from a previous thread.) He says:

 

- the heat-pump is very quiet (he sounded very pleasantly surprised)

- the radiators are working correctly and heating up the place (well, spring has started and temperatures are staying above 0 C, so this is not exactly a test by fire (or ice))

- as for the wind, let's wait until some neighbor complains, and if that happens, we'll figure out something.

 

If I had an easily accessible flat roof, then of course we would have put it up the roof.

[Garald]

Just talked to the contractor directly. (I was getting his comments filtered through the architect, who has some sort of instinctive anti-heat-pump biased, besides almost messing things up majorly, as you may recall from a previous thread.) He says:

 

- the heat-pump is very quiet (he sounded very pleasantly surprised)

- the radiators are working correctly and heating up the place (well, spring has started and temperatures are staying above 0 C, so this is not exactly a test by fire (or ice))

- as for the wind, let's wait until some neighbor complains, and if that happens, we'll figure out something.

 

Mounting it up the wall would surely decrease air intake, unless it's set up orthogonally or at the end of some sort of long protruding arm! If I had an easily accessible flat roof, then of course we would have put it up the roof.

 

Not sure why it wasn't installed at a 90 degree angle. The only reason I can think of is "not creating a wind tunnel with dustbins in the input or output". I got permission to move said dustbins, but I can't think of a permutation that wouldn't have them getting in the way.

Edited March 25, 2023 by Garald