Commercial HVAC / HRV 3 speed fan controller

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Rabbitcat

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#261424 27-Nov-2019 09:29

Hello,

Though not quite DIY/Home, we've got an office where we're installing (DIY) a 2nd hand HRV unit for the ventilation system, and the fans inside the HRV work with a 3 speed controller.

Does anyone know of a cost effective 3 speed fan controller that has the ability to have a timer function ie drop down speed/turn off over night, then start up before people start arriving for work?

We apparently can't do variable fan speed control.

Thanks.

Kickinbac

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#2361831 27-Nov-2019 20:48

What make/model is the HRV?

Rabbitcat

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#2362316 28-Nov-2019 13:25

It's a commercial model from Avon Electric , using heatex core. Here's a screenshot of the fan info

gregmcc

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#2362379 28-Nov-2019 17:07

you could use a manual switch such as

https://www.pdl.co.nz/Trade/Products/ProductDetail?catno=PDL625C3M

or a variable one

https://www.pdl.co.nz/Trade/Products/ProductDetail?catno=PDL625FM

both of these are still manual controls and will require an electrician to install.

If you want some thing fully automatic then you will have to talk to an HVAC company as they will be able to recommend an off the shelf setup, but expect it not to be cheap.

SomeoneSomewhere

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#2364264 2-Dec-2019 00:12

I'd probably use two separate timers, or a timer with two separate outputs. Use one to turn it on/off, the second to adjust high/low.

Usually, these are commissioned to the desired airflow then either run or stopped. There's not much a huge advantage to running them when no-one is present.

Rabbitcat

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#2364562 2-Dec-2019 12:21

Along a similar line, I'm guessing I could have a timer that then feeds into a speed controller. Sort of daisy chaining them together.

Will speak with sparky shortly.

Thanks for all the thoughts.