Author Topic: HRV Installation  (Read 2610 times)

Offline BigK75

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HRV Installation
« on: February 28, 2018, 01:12:43 PM »
I have a quick question on my HRV install. I had everything replaced in my house this weekend including the furnace, AC and a new HRV. Long story short the new HRV (from Venmar Constructo 1.0 -> Healthy Climate HRV4-150) is installed completely differently then the old one.

Anyhow the way they installed doesn't seem right to me compared to my old HRV. I will start in a list of what I think is wrong and if someone could confirm my suspicions and hows its supposed to work that would be much appreciated so I can talk intelligently with the HVAC company:

The HRV and Furnace fan run 24/7 and the furnace fan is on full like as if the furnace was producing heat. Right now I cannot tell if the furnace is producing heat or just running the fan/HRV because the fan is on full all the time. Is this how its supposed to be configured? In the past I don't remember hearing the furnace fan unless heat was being produced and the HRV was dead silent.

The HRV controls that are located in each bathroom and Kitchen that came with the previous unit (a Venmar) where not changed and now they are always on (green light). In the past when using the bathroom or cooking we could press that button and it would start up the HRV. Here is a link to what i am talking about: https://www.venmar.ca/319-accessories-20-minute-lighted-push-button-for-air-exchangers.html

The HRV vents seem to blow out air. I would have thought they suck in air. Those are located all the bathrooms, laundry and kitchen. They look like this. Are these supposed to suck in air or blow air? http://www.cleanaire.co.nz/site/avonelec/images/diff-22.jpg

Was this installed correctly or should I call them back and ask to fix it. This runs nothing like the old HRV did but maybe that's okay. It probably wouldn't bother me but I can hear the HRV and furnace fan all the time and its especially super loud in the bathrooms which is right next to our master bed.

Thanks,

Claude

Offline Admin

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Re: HRV Installation
« Reply #1 on: February 28, 2018, 01:52:19 PM »
Having the HRV interlocked with the furnace fan is normal but there should be an option so that when the HRV starts the furnace fan runs on a lower continuous fan speed.  This really depends on the model of furnace they installed.  The HRV and furnace fan should not be running continuously 24/7. The furnace fan should only run continuously if the thermostat fan is set on instead of auto.  The HRV should only run anytime the main control or touch timers are turned on, in which case the furnace fan will also run.

It sounds like they miswired your touch controls and this is what is likely causing the HRV and furnace fan to run continuously.  The green light should be off until you push the control then it should run for 20 minutes and turn off automatically.

The vents in the bathroom should be sucking air in not blowing air out, so it sounds like they reversed the connections at the HRV.

I would question whether they actually balanced the HRV and look to see if they installed the balancing sticker on the HRV.

Offline BigK75

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Re: HRV Installation
« Reply #2 on: February 28, 2018, 05:08:20 PM »
Thanks Admin this is most helpful and I really appreciate it.  I called them and they are coming back tomorrow to take a look.   So the furnace is Carrier 59TP6 with variable speed fan and is set to auto fan speed and its running 24/7.  I have asked to change to 20 minutes on and 40 minutes off, and to set it up so I can turn it on in the bathrooms, laundry and kitchen by pressing the control as you suggested.  Does that sound appropriate?  I will also ask them to balance it.

Claude


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Re: HRV Installation
« Reply #3 on: February 28, 2018, 06:35:04 PM »
If you unplug the HRV and the furnace fan stops then the wiring problem is at the HRV or furnace, since they didn’t touch your existing controls.  That will be an easy fix.  Also ask them if they used 2 or 3 wires to interlock the HRV and furnace fan.  You want the 3 wire interlock method.  With 2 wires it’s possible it’s back feeding Y and starting the AC and high speed furnace fan.  I assume the AC breakers are turned off so if you did have this problem the AC outside isn’t actually running.

Have them verify the furnace dip switches aren’t in the default position.  They need to adjust SW2-3,4,5 to decrease the continuous airflow and SW2-6,7,8 to adjust the cooling airflow, based on the size of the AC.  If you have a 2 stage AC be careful they don’t lower the continuous fan speed too low as it determines the low stage cooling airflow.  On default your continuous fan is likely around 1200CFM and it could be reduced to around 500CFM.

Reversing the HRV ducts should be an easy fix too.  I would check the exhaust vent outside opens when the HRV is on and blows air out and check the intake vent is a fixed open vent sucking air in.  Also make sure the 2 indoor connections are on the return air duct at least 3’ apart.  The “fresh air to building” duct should be closer to the furnace than the “stale air from building” duct.

Offline BigK75

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Re: HRV Installation
« Reply #4 on: March 01, 2018, 07:04:16 AM »
Thanks Admin.  I will print out the thread and show it to them and see what they say.  If nothing else I would like the fan noise to be reduced, and the time on to be changed to 20min on/40min off so I can actually get some sleep.  I tripled checked the HRV and all the connections are definitely installed right based on your instructions and diagram on the HRV.  I have no idea why it would be pushing air out of the exhaust vents.  This is so strange.  I will update the thread tonight after they show up in case others are curious.

Edit:  I went downstairs with the instruction manual and sure enough they have two pipes backwards like you said.  They have stale air coming from the return and pushing fresh air into the HRV ducts.   It should be the other way around.  The stale air should from the HRV ducts and the fresh air should be pumped into the furnace cold air return. 

Offline BigK75

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Re: HRV Installation
« Reply #5 on: March 02, 2018, 08:21:38 AM »
I thought I would comeback and update the thread.  The HVAC company came back yesterday and fixed almost everything.  They interchanged the two pipes, set the speed to something that is barely audible when the HRV is on and replaced the control panel with the Healthy Climate control that came with the unit.  They interlocked the system so that it now turns off when the HRV turns off.  The only thing they could not get working is the touch control in the bathroom, laundry and kitchen.  The continues to stay on (green light) all the time.  They think this might because they are the old Venmar controls and this unit is the Lennox/Healthy Climate unit.  They will be getting in contact with Lennox today to see if they have any suggestions.  They are thought right now is changing out those controls might fix the problem but want to confirm before they go that route.   

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Re: HRV Installation
« Reply #6 on: March 02, 2018, 05:04:56 PM »
Thanks for the update.  I'm glad they were able to fix most of the problems.  I believe the Lennox HRV is made by Lifebreath and the existing Venmar controls are not compatible.

Offline BigK75

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Re: HRV Installation
« Reply #7 on: March 07, 2018, 05:53:59 PM »
You were right again Admin.  They came back today and switched out all the controls for the 20/40/60 switches and now everything works perfectly.  I am really happy.  Thanks for answering all my questions Admin.  Really appreciate it.