Adam2 Posted November 27, 2021 Share Posted November 27, 2021 I managed to bag one of these at a bargain price a while back and now looking at first fix electrics and think it's worth running some cable for boost switches in case the internal humidity sensors don't act fast enough or if "emergency" boost is required. I have a MRXBOXAB-ECO4 manual (will need to get one more as the design is for 2 units largely due to duct run lengths). These units will serve: Unit 1: 2 x en-suite bathrooms + 1 separate WC + kitchen + utility Unit 2: 2 x en-suite bathrooms + 1 separate WC I'd like to have something simple so not wanting to link this up with home automation. ideally I'd have a retractive switch in each en-suite (possibly also WCs) and in the kitchen to trigger boost for a set duration. I can't see in the manual if that is possible - there is mention of the eco-smart sensor connectors and optional switches etc which looks like buying some more Nuaire bits - which is OK if needed but may be nicer switch options. Doesn't look like enough info in the manual to see how you can wire up a simple momentary switch to trigger a boost as far as I can see but if anyone has already done this or can see a way that would be super helpful. Link to comment Share on other sites More sharing options...
ProDave Posted November 27, 2021 Share Posted November 27, 2021 I use this type of timer for my boost switches. https://www.tlc-direct.co.uk/Products/SMSTBT4.html They give a switched 240V output and that drives a small relay that then connects to the MVHR. The details of how to switch your particular mvhr will need to be answered by someone familliar with your unit. Link to comment Share on other sites More sharing options...
Adam2 Posted November 27, 2021 Author Share Posted November 27, 2021 Thanks @ProDave I found something similar from Nuaire designed for their systems which would be OK but hoped there may be a way to just use a standard momentary switch to close the circuit to a boost input. Will be able to contact them Monday if needed and see if they have any alternatives. Link to comment Share on other sites More sharing options...
JohnMo Posted November 27, 2021 Share Posted November 27, 2021 We have momentary switches at bathroom, en- suites and kitchen, didn't bother with utility. Leave the boost timing to those set in the mvhr. Have humidity sensors, but hit and miss if the fire up, seemed ok in September, but now you have two showers running and no response, so glad I installed the switches. Link to comment Share on other sites More sharing options...
Adam2 Posted November 30, 2021 Author Share Posted November 30, 2021 Seems there is no in-built boost timer so will need to use momentary switch from each location to a timer which can then drive the switch live for x mins to activate boost control. Their normal approach is to run this from the light switch but we don't like that so now looking for a nice set of controls to do this - in-room switch that can trigger a time delayed live feed - contemporary suggestions appreciated, otherwise we'll hide an ugly switch in a cupboard! Link to comment Share on other sites More sharing options...
PeterW Posted November 30, 2021 Share Posted November 30, 2021 Shelly 1 with a humidity sensor. Can also add any number of momentary switches (in parallel) and also switch from the phone / app etc for change of £30 Link to comment Share on other sites More sharing options...
Adam2 Posted November 30, 2021 Author Share Posted November 30, 2021 Thanks @PeterW I'm planning installing HA - mainly Zwave but some Zigbee (with Hubitat controller). I had wanted to keep some things separate from HA if they didn't have to be included so for MVHR the default would be the inbuilt humidity detection + some form of backup switch control to trigger boost manually if needed. One thing I haven't experimented with yet on the HA side is how to interface between electric components that don't directly connect to an HA control unit - so in this example if I were to use a HA humidity sensor or even a HA switch to identify an "event" of interest, do I just wire the MVHR boost sensor into a HA relay and trigger that? Link to comment Share on other sites More sharing options...
PeterW Posted November 30, 2021 Share Posted November 30, 2021 Depends but some are just a dry contact that needs triggering - what does the unit installation guide say..? Link to comment Share on other sites More sharing options...
Adam2 Posted November 30, 2021 Author Share Posted November 30, 2021 The install guide isn't so helpful seems to refer to wiring into the lighting circuits for boost when bathroom light is on. Feels like there should be a more in-depth guide also covering the grey wire which I think is for the max boost trigger (with black being normal boost) Link to comment Share on other sites More sharing options...
PeterW Posted November 30, 2021 Share Posted November 30, 2021 Yeh just read that. So is it mid position with no feed as ‘normal’, black is boost and grey super boost..? Link to comment Share on other sites More sharing options...
Adam2 Posted November 30, 2021 Author Share Posted November 30, 2021 27 minutes ago, PeterW said: mid position with no feed as ‘normal’, black is boost and grey super boost..? I think so yes - amazing there is not more info available but Nuaire do answer their phones so I can go back to confirm before I blow it up. Link to comment Share on other sites More sharing options...
Adam2 Posted December 1, 2021 Author Share Posted December 1, 2021 (edited) @PeterW what bits and pieces would I need then to trigger this for a set duration if I were to use "traditional" or an HA approach? Traditional - momentary switches in each location with a switched live connected to some sort of central component that will allow any of the inputs switched to trigger the switch live to the MVHR on the boost line (for now just thinking about using the std boost). Just not sure what the intermediate thing would be called? With HA I could use 3 x momentary switches with HA module and detect when one is pressed then activate a relay for a set period - correct? Edited December 1, 2021 by Adam2 Link to comment Share on other sites More sharing options...
PeterW Posted December 1, 2021 Share Posted December 1, 2021 You can use a latching or timer relay if you don’t want to use HA - this would do it. You can set the on time for as long as you want (10 mins etc) the do all the switches in parallel. 1 Link to comment Share on other sites More sharing options...
Adam2 Posted December 1, 2021 Author Share Posted December 1, 2021 Nice to be well informed when I speak with my sparky. Yes I think for HA this will provide a simple solution. Will save my HA excitement for my motion sensor to trigger a welcome message for my wife and request a nice cup of coffee in the morning ? Link to comment Share on other sites More sharing options...
MJNewton Posted December 2, 2021 Share Posted December 2, 2021 (edited) I'd suggest going with the Shelly relay option acting as the boost controller with physical switch inputs thus giving 'standalone' functionality with no external dependencies. You could program different boost durations for short vs long switch presses if you wish. If you then wanted to add event-driven HA control later just get HA to request the boost via Shelly's HTTP API. Edited December 2, 2021 by MJNewton Link to comment Share on other sites More sharing options...
Adam2 Posted December 2, 2021 Author Share Posted December 2, 2021 @MJNewton thanks for the suggestion. Not looked at Shelly much - main HA is Zwave based so could use a Fibaro relay here, presumably load is pretty small as it's just a trigger not running the MVHR. This approach could be a good option for future HA enhancement - eg adding boost from non-switched areas like WCs. For this to work then I'd wire the 3 switches in parallel connect to the input on the HA relay and have the switched live output connect into the boost input cable for the MVHR? The HA I could program to provide a timed output which I could easily change and no issues with signal as all wired! nice Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now