Stones Posted January 27, 2017 Share Posted January 27, 2017 Like quite a few others here, I bought my MVHR and ducting from BPC. As part of their package they supplied two ventilation boost rocker switches, to allow remote boost activation of the MVHR. Having left in drawstrings for cables, I'm now at the point of deciding whether to bother with these switches at all, as I can program a timed boost to the ventilation rate to coincide with morning showers (this is in addition to the inbuilt humidity sensor), and I will always have the ability to boost ventilation rates from the master controller which will be located centrally in the house. Firstly, just looking for any feedback, good or bad about the switches and whether those who have installed feel they are worthwhile. Secondly, on an installation note, BPC instructions indicate a 1mm 3 core cable from switch back to the MVHR unit. Which terminal connection on the unit did you use to connect these switches? 1 Link to comment Share on other sites More sharing options...
Bitpipe Posted January 27, 2017 Share Posted January 27, 2017 Another BPC customer here, we wired the MVHR boost function (sentinel Kinentic +) to activation of bathroom light switches and also put a PIR in for daytime activation. These also activate the secondary return pump for DHW. So we had no need for the switches. 2 Link to comment Share on other sites More sharing options...
worldwidewebs Posted March 29, 2017 Share Posted March 29, 2017 On 27 January 2017 at 20:11, Bitpipe said: Another BPC customer here, we wired the MVHR boost function (sentinel Kinentic +) to activation of bathroom light switches and also put a PIR in for daytime activation. These also activate the secondary return pump for DHW. So we had no need for the switches. Doing first fix wiring now and working out how best to control MVHR boost. How are you finding it working off the PIR and light switches? As an aside, when in boost mode, is the system any noisier in the rooms with inlets? Thinking specifically of bedrooms Link to comment Share on other sites More sharing options...
Bitpipe Posted March 29, 2017 Share Posted March 29, 2017 Boost airflow is marginally noiser - you actually only really notice when it switches off if that makes sense. Not sure how the electrician wired up all of the PIRs and light switches to activate boost (and also the secondary pump, both work off the same switched live), but can ask him. Link to comment Share on other sites More sharing options...
worldwidewebs Posted March 29, 2017 Share Posted March 29, 2017 Thanks Do you have a boost function in all locations that have an extract or just the bathrooms? Link to comment Share on other sites More sharing options...
ProDave Posted March 29, 2017 Share Posted March 29, 2017 Late to this thread (must have missed it first time around) I don't like the idea of a rocker switch. To me that means you turn it to boost and then later turn it back to normal. I am planning to have in the kitchen, and next to the bathrooms a timed "boost" switch, probably thinking along the lines of the Horstman immersion heater boost switches where you can typically boost if from 15 minutes to over an hour in steps. This will need a relay or two to interface it with the mvhr. but I like the idea of push the button get in the shower and forget it. Some time later it will switch itself back to normal. Link to comment Share on other sites More sharing options...
Barney12 Posted March 29, 2017 Share Posted March 29, 2017 Do I assume the mechanism for these boost switches is a simple volt free NO/NC type setup? Just thinking I might link mine to my c-bus lighting setup. That way I can add some simple intelligence using PIR's etc. Link to comment Share on other sites More sharing options...
Bitpipe Posted March 29, 2017 Share Posted March 29, 2017 2 hours ago, worldwidewebs said: Thanks Do you have a boost function in all locations that have an extract or just the bathrooms? We have the 'auto boost' in the 4 bathrooms and the MVHR controller, which has a boost function, in the utility. Our cooker hood is not compatible with the cooker hood mode of the MVHR so theres a plan to put a current sensor on the supply for that to work. On our MVHR, any boost signal runs the boost for 10 mins, you can't turn it off. 1 Link to comment Share on other sites More sharing options...
worldwidewebs Posted March 30, 2017 Share Posted March 30, 2017 Many thanks Hugh Link to comment Share on other sites More sharing options...
Calvinmiddle Posted March 30, 2017 Share Posted March 30, 2017 We have two timed switches, one in kitchen and one in the Not Hot Press near the bathroom. These are switches that can be adjusted to be "on" for between 20-120 mins, I got these in error as meant to buy the 2-20 minute version. so before you go for a shower or are cooking we hit the boost button. i have a humidistat on the MVHR and just haven't found it to work well. when I try and adjust it to run when the shower is on (bathroom extract above shower on wall about 3m off ground) it just runs all the time - maybe I didn't spend enough time setting it finely enough but the boost button is just not a hassle and life's too short to mess around with something like that. Didnt want it set to a light switch or a pir as it only needs to come on when the shower is on or if someone is cooking Link to comment Share on other sites More sharing options...
Bitpipe Posted March 30, 2017 Share Posted March 30, 2017 Here comes the science bit.... "The switches and PIRs are basically just wired in parallel, the boost connections only usually give you the switching pair but the PIRs require a neutral so picked that up from the MVHR unit and then wired the whole lot by daisy chaining between each point with 3 core & earth with the neutral just connected through (separately to the local lighting neutral to avoid RCD tripping) in each conventional switch. The switches are double pole switches so that the local light switching is in one side of the switch and the MVHR boost in the other" Link to comment Share on other sites More sharing options...
PeterW Posted March 30, 2017 Share Posted March 30, 2017 The Timeguard PIR switches from TLC allow you to remove the factory link and become volt free if you have a need for that on your MVHR. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted March 30, 2017 Share Posted March 30, 2017 Worth noting that some MVHR units (like ours) use an isolated dry contact boost switch, so must not be connected to one side of a mains switch. IIRC, the dry contact connection on ours is between the internal 0V rail (connected to earth) and a sense supply that's very low current at 24V DC. That DC supply also runs the control unit, which is an ELV bit of kit, so again there is a safety risk if a combined switching system is used, as there needs to be isolation. Link to comment Share on other sites More sharing options...
joe90 Posted March 31, 2017 Share Posted March 31, 2017 Jeremy, have you fitted boost switches or do you rely on a humidistat sensor ? Link to comment Share on other sites More sharing options...
vivienz Posted October 8, 2019 Share Posted October 8, 2019 Giving this thread a bump. My bathrooms and downstairs loo have a switch next to the light switch, on the same face plate, that is to allow a timed boost to the MVHR to extract any overly pungent smells after the deed has been done. Although the switches are there (they are rocker switches, I believe) there is no circuitry to link and tell the MVHR system what to do. What should I be looking for to put this right rather than have redundant and confusing switches? Is there a proprietary box of tricks that can be purchased? Thanks. Link to comment Share on other sites More sharing options...
Barney12 Posted October 8, 2019 Share Posted October 8, 2019 13 minutes ago, vivienz said: Giving this thread a bump. My bathrooms and downstairs loo have a switch next to the light switch, on the same face plate, that is to allow a timed boost to the MVHR to extract any overly pungent smells after the deed has been done. Although the switches are there (they are rocker switches, I believe) there is no circuitry to link and tell the MVHR system what to do. What should I be looking for to put this right rather than have redundant and confusing switches? Is there a proprietary box of tricks that can be purchased? Thanks. The answer will in part depend on the make/model of your MVHR unit. As an example I have an Airflow Androit unit. The "boost" is controlled by a volt free normally open circuit. Thus a "bell press" type switch will activate the boost. As I mentioned above I linked mine to my lighting system. A second button in my bathrooms is programmed as a bell press and activates a relay which closes the circuit. 2 Link to comment Share on other sites More sharing options...
vivienz Posted October 8, 2019 Share Posted October 8, 2019 My unit is an ecocent from earthsave products; other than that, I can't tell you much about it, I'm afraid. Link to comment Share on other sites More sharing options...
Dreadnaught Posted October 8, 2019 Share Posted October 8, 2019 (edited) Oh you might have an exhaust-air heat pump in your MVHR! This one https://www.earthsaveproducts.com/products/mvhr-including-built-in-heat-pump/ecocent-air-mvhr. There is a link to the manual on the web page. Unfortunately, the manual does not seem to mention the word "boost". If that is your model, you might be interested to know that both @Mikey_1980 and @dogman have the same one. Edited October 8, 2019 by Dreadnaught 1 1 Link to comment Share on other sites More sharing options...
vivienz Posted October 8, 2019 Share Posted October 8, 2019 Ah, thanks. It seems that I have some redundant switches, then. Link to comment Share on other sites More sharing options...
Adsibob Posted April 9, 2021 Share Posted April 9, 2021 (edited) On 29/03/2017 at 21:23, ProDave said: Late to this thread (must have missed it first time around) I don't like the idea of a rocker switch. To me that means you turn it to boost and then later turn it back to normal. I am planning to have in the kitchen, and next to the bathrooms a timed "boost" switch, probably thinking along the lines of the Horstman immersion heater boost switches where you can typically boost if from 15 minutes to over an hour in steps. This will need a relay or two to interface it with the mvhr. but I like the idea of push the button get in the shower and forget it. Some time later it will switch itself back to normal. The Boost switches that CVC sell do exactly that. They are "bell press" switches. You press and forget about it as it automatically rocks back to the off position. It just boosts for a progammable amount of time. Edited April 9, 2021 by Adsibob 1 Link to comment Share on other sites More sharing options...
Jenni Posted May 8, 2021 Share Posted May 8, 2021 Hi. I'd really like some help/advice with regards to boost switches please. I have a vent axia sentinel kinetic advance s, which I'm running wires for first fix at the moment. I'd like to wire 2 separate switches to boost the unit (1 located nr bathroom and 1 in kitchen). Am I right in thinking the unit itself copes with the timing of the boost, and therefore the switches can just be simple momentary rockers? (I'm hoping so as would like to use a bell press architrave switch). If so, what cable do I need to use please? Link to comment Share on other sites More sharing options...
Marvin Posted May 8, 2021 Share Posted May 8, 2021 Page 27 of the manual indicates a permanent supply. https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.vent-axia.com/sites/default/files/476930.pdf&ved=2ahUKEwiahruBs7rwAhXGsKQKHeUpAysQFjABegQIEhAC&usg=AOvVaw3CfH1v-diGhHk3-AayMijT unless I have this wrong... . Link to comment Share on other sites More sharing options...
Marvin Posted May 8, 2021 Share Posted May 8, 2021 Reading further it seems you can programme for booster to go on and off at the unit but electrical terminal LS1 seems to be an override. Good luck. Link to comment Share on other sites More sharing options...
Roundtuit Posted May 8, 2021 Share Posted May 8, 2021 We put 3 boost switches (ventaxia momentary boost switches) on our system, one outside each bathroom/loo, and never use them tbh. To be sure it activates the boost, you have to hold it pressed for a couple of seconds, and then airflow returns to normal after a set period. Sorry, can't help with the cable spec. Link to comment Share on other sites More sharing options...
Marvin Posted May 8, 2021 Share Posted May 8, 2021 3 hours ago, Roundtuit said: We put 3 boost switches (ventaxia momentary boost switches) on our system, one outside each bathroom/loo, and never use them tbh. To be sure it activates the boost, you have to hold it pressed for a couple of seconds, and then airflow returns to normal after a set period. Sorry, can't help with the cable spec. That sounds like a time delay action. So you hold switch down until it activates and then it delays turning off for the programmed amount of time. If you have a normal switch it will stay on and when you switch it off it will continue for the programmed amount of time before shutting off ( think time delay on extractor fan). I use neon switches so you can see when it's left on. Unless someone knows otherwise of course.... Good luck Marvin Link to comment Share on other sites More sharing options...
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