Thought I’d start this as I’m interested in understanding fan noise on my R290, hopefully I can reduce it when Grant release the fan speed control in econet24, for now just sortof using this as a place to document things.
First thing, I’m very certain now that the ASHP goes to 650rpm when the ambient sensor on the ASHP itself gets to 5c, I think there may be a delay or dwell time e.g. delay changing fan speed by a few mins, or ensure 5c or below has been present for a minute or do, but you can clearly see the behavior below
That interesting, I had assumed that it always ran at 650rpm, it does indeed seem to follow the ambient sensor rather than outside temp sensor.
I generally use one of the two silent modes
Level 1: ~400rpm/40Hz maximum
Level 2: ~450rpm/50Hz maximum
I’d really like an option to manually select maximum Hz and fan speed, alternatively another level at ~500-550rpm/60Hz. I can generally use level 1 or 2 until it gets to about 1c.
The fan noise isn’t that loud for me even on full throttle but it does have an annoying high pitched ringing (variable frequency drive?) that I can hear when outside regardless of fan rpm.
I agree it would be great to be able to manually specify max hz and fan, or yes another level of silent would be good. My house would struggle on either silent mode when any lower than probably 4c I think, and it incurs additional defrosts I think.
I get the impression Vaillant units are much more limiting with fan speed? Possibly I’m wrong.
I don’t get any whining but more of a deep bassy fan noise, I think perhaps how mine is positioned makes 650rpm quite noisy. I mean it’s not awful but not at all quiet.
Interesting, My 9kW HP290 runs the fan at 400 rpm all the time apart from during defrost cycles. It’s totally inaudible inside the house, even during defrost:
You’re on silent mode though right Glynn? You must be on level 2 where your fan is capped at 400 rpm and compressor at 40hz.
Edit - sorry I suppose I didn’t say in my first post, the rule of 650rpm only applies when not in silent. I’ve never seen silent budge off anything other than the respective 400 or 450rpm.
Also note, I’ve seen another speed which is 700rpm. I’ve lost the data due to HA averaging it, but I think that triggers roundabout -4. Not sure if it goes any higher or whether 700 is flat out.
I’m curious about silent mode - what’s your view on defrosts? It seems to me that silent mode is more efficient, however being as the fan spins slower it does seem defrosts are more frequent as the temperature drops vs “normal” mode, I wonder at what rough temperature silent mode becomes less efficient.
It’s a good question, I seem to have observed the opposite. Since silent mode stops, the compressor ramping up to 100% it increases the time between defrosts since the evaporator temperature does not drop as quickly.
If the outdoor temperature drops below zero for extended periods, I will need to reduce the silent mode level or switch it off to get more heating power. So it’s not really the best solution.
I have found the same thing with the Samsung unit. Quiet mode increases defrost frequency. When I leave quiet mode off & limit the compressor frequency I can sometimes get down to 2 degrees before it starts frosting (depending on humidity). With quiet mode on, it starts at 5-6 degrees.
So with silent mode enabled you find you get fewer defrosts? Not more?
So you’re saying you can only get as low as 2 with silent mode if you limit the compressor? If you don’t limit it then you can see them around 5 or 6? The latter is what I observe - defrosts can start around the 5c mark depending on humidity, and the Grant units don’t allow limiting the compressor independent to silent mode - basically silent mode is the only way to limit the compressor. With level 1 it’s 50hz, with level 2 it’s 40hz.
I guess it makes sense to me to have more defrosts in silent mode - lets say I was on normal mode and it was 4.5c, in those conditions my fan would be at 650rpm and my compressor would quite probably be around the 40hz ish mark in steady state running, so if I turn on silent mode the compressor would still remain at 40 (because it hasn’t exceeded the cap) but the fan would be running at either 450rpm or 400rpm depending on the mode, so the evaporator could would be colder.
Ah gotcha, yeh that seems to make sense. Great that you can se a compressor limit separately, we can’t do that with the Grant units, I would absolutely love to see a really hackable / in depth controller where you could just do a lot of this yourself - e.g. custom weather comp curves, fan and compressor limits at different temps etc, I think you could really increase COP.
Exactly the same for me, I’m not seeing more defrosts. When not on silent mode its almost too aggressive which can trigger them. My preference is keeping in level 2 as long as it can provide enough heat.
@MrW you’re correct, silent mode 2 is the more restrictive 40Hz.
What is the general consensus on flow rate (min and mix pump speed)?
I’ve found that things can go a bit wrong if i drop below 35 min (15 L/min) which gives me a ΔT of about 3.5c in mild weather flow temp of 32/33. I’ve bumped it up to 44 min (17.5 L/min) which is giving me a tighter ΔT of about 2.5c in mild weather. Better COP but i’m not sure whether ΔT is too small.
@glyn.hudson, did you update via the econet app, which keeps telling me version 3.2.3881 is available, or by using a microsd card in the wall display? reluctant to mess with mine until spring, though silent mode would be a boon ..
