I'm personally surprised ocotpus doesn't have a dedicated noise ninja team that nips these issues in the bud as soon as they are detected. There is nothing more powerful than this happening to someone and turning them into a heat pump detractor. Worth it to "save" these 1% of jobs.

@swwils I can’t recall if one has to be an existing (and continue to be) an OE energy customer to have a Cosy heating system installed or not. Toodles.

@toodles they were great when combined with really, really, large UFH systems.

@l2jad May I request clarification on method of measurement please? When you mention over 100dB in front of the fan, are you using a means of wind shielding in front of the microphone? To report a difference of some 40 dB suggests that you may be exposing the microphone to wind blast which would certainly influence the resultant reading. Toodles.

@toodles it has one of those black covers you stick over the microphone part. Supposed to shield from wind noise.  To be honest that's not the way to measure it, I only brought the meter to confirm how loud it sounds, not by me but 3 other people. Pointless videoing as you can turn the volume up you need something to compare it with. 

When they are standing 40m down the road and can hear a blowing noise like a very very strong wind, during the day not in the dead of night, it sort of says perhaps its loud, hence I purchased the meter.  I can stand 8 to 10m away in front of the unit and it still measures 60db. Meter near the bottom of the unit ie at the case not touching is 75db and thats not when its really going for it.

I’m guessing you probably have a cosy 9 which i’ve watched a lot of you tubes with people standing nearby  presenting, yes they get dome wind noise but you won’t do that in front of this cosy 12.

it’s not just me i know of 3 other installs where people are not happy with the noise you could not live with this!!!

@toodles i will add just been out and checked now it is running but its like on tick over and could 100% live with that, not sure technically why it is running at the speed it us, but heating says warming up very close to temperature!!! I don’t know if they have firmware updated it, but no roar at present!!!!!! Would be very happy at this level, which is 59db at bottom of unit yes 75db at fan but that’s a lot less than the 100+ reading I had. 

shall leave on tonight and see if i wake with a knife in my back 😉

@l2jad I had a Daikin Altherma 3 Monobloc 8 kW ASHP which was installed previous to OE introducing the Cosy heat pump. My particular interest in the method used to record the sound level is because I had a career as an Audio Technician and part time Sound Engineer. Making sound recordings in an environment with significant air movement is fraught with difficulties. Toodles.

@l2jad 😱 Good Luck! Toodles.

@toodles thank you, i took measurements from various locations with the black cover, most were close to unit but out of wind were in the mid 70’s. No where near that tonight.

i’m going to check the unit again before bed if its still reasonably quiet i will set the fallback to 1 degree tonight i lost around 2 to 2.5 degrees last night so i know it should cause the pump to start plus hot water will kick in, see if i have a knife in my back in the morning. Really hope it works quite fond of wife.

I wonder if there’s been a firmware update recently.  It’s 3c outside and the Cosy is quiet which is unusual.  It would have been  noticeable at this temp in the past.

@andrewj mines the opposite, louder than normal 😂

Mine had funny spells, earlier when it was in heating cycle seemed like low fan revs and acceptably quiet, 10 minutes later i had what seemed like full tilt rev’s  75db at cover part of unit same at back. Edge of wind flow 85db not bothering measuring in wind flow. 10m away i’m at 60 to 65. You don’t hear that cover measurement due to the wind noise!

Measured in my garage with door shut that’s 3m from side of pump 55db to 60db.

last nights test, fall back 1 degree (17.5) 9pm

The house during the day was at 18.5 

Pump started around 3am very loud, hot water kicked in at 3:30am only took 20 mins to get to 50deg, heating carried on heating nosily.

The only solution i see with current fan design is lower the speed,

ps at full tilt running you can hear flapping at the grill.