Evohome is Noisy - please help me

[DBMandrake]

As a difference of 3dBA is barely perceptible to the human ear,

I have to take issue with that. I've spent some time building and measuring loudspeakers in the past and a 3dB change in SPL is easily audible, and a 3dB change in frequency response is plain as day.

The frequency response comment is relevant when you are starting with "background noise" of roughly even frequency distribution and then adding a periodic noise like a whirring motor that occurs at very specific frequencies, thus changing the overall frequency response of the summed sound. You are not just taking a specific sound and increasing its volume by 3dB.

A noise like a whirring motor with specific tonal characteristics can actually be distinguished even if it is "below" the background noise level. This is because the background noise level of 34.6dB is the sum of the power in all frequencies in the A weighted range, while the noise of the HR92 will be concentrated at just a few narrow harmonic frequencies. At these frequencies it is very likely 10-15dB above the noise floor of the background noise for an average dBA reading of 3dB greater.

Trying to make this sort of comparison with a simple dBA meter is a bit meaningless as it doesn't take into account the spectrum of either the background noise or the HR92 whirring, therefore doesn't take into account masking etc. Looking at the output of a spectrum analyser would be more useful but is a bit beyond a simple test! A spectrum analyser would show that the peaks of the HR92 noise would be a long way above the noise floor not 3dB.

It all comes down to how easily you are annoyed by certain kinds of noises though and what your background noise is like in the rooms whether its a problem for you or not.

For me I'm yet to be woken by the bedroom HR92 and I can just hear it if I'm already awake. Our 8 month old could sleep through a marching band once he's properly asleep so no problems there either.

I can totally see that some people might not be happy with the noises they make though, but I can't see how it could be made much quieter at an economic cost and when you consider just how much force (a lot) is required to push down the pin. It's already geared down a lot, such that it takes over 30 seconds to wind from one extreme to the other. If the noise is that much of a problem then going back to silent, manual TRV's is probably the only option.

[DBMandrake]

It doesn't even need to be annoying. How many of us in the "the noise is acceptable" camp have started to hear our HR92s more since this thread started? I know I have.

Not to the point where they become annoying though.

I've always heard mine, but never found it obtrusive, and they don't bother me any more after this discussion. The hallway and bathroom ones are quite noisy due to the acoustics of those rooms, but I don't particularly care about those rooms being quiet.

The living room one is nice and quiet both because of carpet and sofas, and the fact that there is no direct line of sight from the listeners ears to the HR92 due to the positioning of the sofas. This helps a lot I think as only reflections that have bounced off something soft and absorbent will reach the listener.

Likewise in the bedroom although the floor is bare laminate you have a massive big duvet acting as sound absorbent material, also the layout of the room and wardrobes means that once again there is no direct line of sight from the HR92 to our ears when we're in bed, I have to strain to hear it in a quiet room if I'm already awake. If there is any traffic noise going by it drowns it out.

Only the big long sweeps from open to closed or closed to open are noisy - the small adjustments made to maintain the temperature are both short and generally quiet. We have the bedroom scheduled to 16 degrees through the night rising to 18 in the morning so the valve is already at the opening threshold to maintain 16 degrees so doesn't have to turn much to increase the room to 18. If it was scheduled to 5 through the night I'm sure it would make more noise since the motor would be turning for a good 30 seconds to open instead of maybe 2-3 seconds.

[paulockenden]

Interesting that this thread hasn't altered your perception of the noise. It certainly has here. Wonder what others have found?

[Arrghh!]

How annoying it is depends on your particular circumstances. I have been woken by the HR92 in my bedroom, but then it is approx. 2 metres from my ear when I'm lying in bed with direct line of sight.

If the rad was on the other side of the bedroom, I'm sure I'd hardly be able to hear it.

I'm not bothered and don't really notice the other HR92s in my house, apart from one in the living room which again is about 2m from where I usually sit.

I would like to find a way to make those two actuators quieter if I can, but I'll live with them if I can't. I certainly wouldn't uninstall Evohome because of it.

[paulockenden]

If you have a separate room stat I wonder whether a length of pipe lagging slid over the HR92 would work? You could arrange it to that it overlapped the top and bottom, and maybe even fill in the openings at each end.

My only concern would be you might cook the batteries.

[Cchris]

Bit of a pain, but depending on the size and position of the radiators, perhaps swapping the valve and HR92 to the opposite end would help? It may just be that extra bit of distance that would make all the difference.

[DBMandrake]

If you have a separate room stat I wonder whether a length of pipe lagging slid over the HR92 would work? You could arrange it to that it overlapped the top and bottom, and maybe even fill in the openings at each end.

My only concern would be you might cook the batteries.

As opposed to having it exposed to the direct radiant heat of the side of a radiator which is up to 80 degrees and just a couple of inches away ?

To have such a long battery life the heat output of the HR92 must be infinitesimal. It will generate a small amount of heat when the motor turns but that will be inconsequential, and it will generate nothing to speak of when it is idle.

Wrapping it up in insulation is going to keep it at a more steady moderate temperature, so I really can't see it being hurt by insulation. Ugly - but probably effective! As long as you have a wall stat to measure and optionally see and adjust the temperature you really don't need to see or get at the HR92 except for battery changes...

Has anyone tried stuffing a thick Christmas or heat keepers sock over one ? Might be a reasonable workaround for a bedroom...

[Arrghh!]

Bit of a pain, but depending on the size and position of the radiators, perhaps swapping the valve and HR92 to the opposite end would help? It may just be that extra bit of distance that would make all the difference.

With my layout, that would move it closer to me

Covering the HR92 in some way is the simplest solution as long as you can sort the temperature sensing, but making it look neat is going to be difficult.

When dot matrix printers were first put in offices, we had to put them in acoustic hoods. I'm thinking of something similar which would still allow the display to be seen and wouldn't look too untidy.

I think I'm going to put an external sensor in my bedroom anyway, as the window above the radiator is open at night and is making it difficult to get the balance right in there. So if I do that, I'll play around with HR92 covers and see what I can come up with.

I'm assuming all I need to do is buy a DT92E and change the sensor type in the control panel for that zone?

[paulockenden]

To have such a long battery life the heat output of the HR92 must be infinitesimal.

I was thinking of the heat rising from the valve below into what effectively becomes an insulated oven.

P.

p.s. if your rads are 80 degrees you're doing something wrong. Or working in Fahrenheit!

[DBMandrake]

If you sleep with the window ajar as we usually do then a remote DT92 is definitely recommended. As you note cold air coming down from the window across the HR92 will affect the reading and cause the radiator to come on when it shouldn't, and it is quite difficult to find a set point that is comfortable on any given night, or works well as the seasons change. We added a DTS92 to the bedroom for this reason - on the wall above the head of the bed and it works brilliantly.

if you have the Wi-Fi controller all you need to do is go into the zone configuration for the zone and select a new sensor, bind the DTS92 and you are done. If you have the older controller you'll have to go through the binding process for the zone again, binding the DTS92 first and the HR92 second.