Ducted heatpump + lossnay ventilation + airtouch

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orca7

2 posts

Wannabe Geek

#316057 12-Sep-2024 12:16

Hi, everyone. I see there are a number of posters here with these systems so please allow me to post here.

We recently had Mitsubishi ducted heatpump and lossnay ventilation systems installed in our house with Airtouch 5 zone control for each room.

Mitsubishi Electrical PEA125HAA ducted heat pump system
Mitsubishi Lossnay VL220
Airtouch 5

One room with higher humidity(condensations) still gets condensation in the room. We were hoping that the lossnay ventilation system would fix this. It almost seems it has no effect..

What we have done so far is to switch off the heating(ducted) for the particular room overnight via Airtouch but the Lossnay system is still on at low fan speed. I have noticed that there is no air coming out of a diffuser in the room so I feel no air flowing out of the room under the door.. would this be why we still have condensation in the room because moisture is not coming out of the room?

If I switch off ducted heating for a room, should fresh air be coming out of the diffuser from the lossnay ventilation system? or does switching it off shut the ducting completely for the room? if so, how can the room be ventilated?

What could we do to get rid of the condensation in the room?
Also, our lounge is getting overheated when the zone(lounge) should be off. I'm guessing that the lounge is set as a spill zone. What can I do so the space gets less overheated?

Thanks so much.

timmmay

20581 posts

Uber Geek

Trusted

Lifetime subscriber

#3281476 12-Sep-2024 15:00

Welcome to Geekzone 🙂

Suggest you go back to your installer about the integration between Lossnay and the heat pump. If a room is turned off I'd be surprised if any air is going through it assuming you only have one set of ducting and diffusers. You could ask for / draw a diagram of how it's all connected together. I wouldn't heat / cool rooms that I'm not using like spare rooms, but all rooms being used obviously I would heat / cool.

Even with ventilation and ducted systems and double glazing you will still get condensation. It should be less than without the systems in place. If you're single glazed I suspect you'll get a lot of condensation. We have Airtouch 4 and double glazing, we still use a window vac on the colder mornings in Wellington.

tweake

2391 posts

Uber Geek

#3281520 12-Sep-2024 17:06

typically the ventilation air is feed into the heat pump duct system and uses the heat pump fan to circulate the air. the ventilation system is actually wired to the heat pump for that. but if you shut off the heat/cooling to a room with a damper, then you also shut off the ventilation.

personally i would heat/cool the whole house rather than room by room. unfortunately kiwis have been well taught to heat room by room because of our crappy houses. if your house is air tight enough to warrant spending the money on balanced ventilation then hopefully its good enough you don't have to resort to room by room heating.

on that note, a common problem that you might have seen in the media with the "insulation is making nz house to hot" bs scam someone tried to pull, is that kiwi homes are often poorly designed with way to much solar gain in the lounge area. that results in a hot lounge and makes balancing cooling loads difficult.

also keep in mind, because its an HRV instead of an ERV, your humidity in the house will be dictated to by the outdoor humidity. eg if you run a lot of ventilation your also going to pull in a lot of summer humidity which might be a bad thing depending on where you live and what humidity level you want.

details on the house and duct setup would be handy. are you using exhausting the bathroom through the ventilation system? also has the house been blower door tested?

Dono

26 posts

Geek

#3281552 12-Sep-2024 19:48

When you turn off a zone it closes off the Airtouch damper for that zone, so that would be why you don't feel any air coming out. From the installer manual: "When the set point has reached, the damper of the group will not be fully closed but have the set Min Vent opening to circulate the air. But if the group is turned off, the damper will be fully closed."
If you want air to continue to circulate you need to leave the zone turned on and it will flow at the minimum vent setting.

orca7

2 posts

Wannabe Geek

#3281652 13-Sep-2024 11:06

Timmmay, Tweake and Dono, thank you for your responses.
Right, it's starting to make more sense now!
A couple of things to try for us

set temp to 19 degrees in heating mode overnight, according to Dono's information, it may ventilate the room (When the set point has reached, the damper of the group will not be fully closed but have the set Min Vent opening to circulate the air)
use 'fan' mode overnight at lowest fan speed. not so keen on this idea tho as I'm worried that it may cool the room too much

tweake

2391 posts

Uber Geek

#3281784 13-Sep-2024 17:12

orca7:

Timmmay, Tweake and Dono, thank you for your responses.
Right, it's starting to make more sense now!
A couple of things to try for us

set temp to 19 degrees in heating mode overnight, according to Dono's information, it may ventilate the room (When the set point has reached, the damper of the group will not be fully closed but have the set Min Vent opening to circulate the air)
use 'fan' mode overnight at lowest fan speed. not so keen on this idea tho as I'm worried that it may cool the room too much

ventilation system 'talks" to the heat pump so the heat pump runs its fan when ventilation is on. the ventilation should always be on, therefore the heat pump fan should always be on without having to set anything.

thinkingtrex8848

533 posts

Ultimate Geek

ID Verified

Lifetime subscriber

#3290006 2-Oct-2024 12:50

orca7:

Hi, everyone. I see there are a number of posters here with these systems so please allow me to post here.

We recently had Mitsubishi ducted heatpump and lossnay ventilation systems installed in our house with Airtouch 5 zone control for each room.

Mitsubishi Electrical PEA125HAA ducted heat pump system
Mitsubishi Lossnay VL220
Airtouch 5

Would you mind if I ask what this system ended up costing fully installed?

Or anyone else with a similar system be able to advise on approx pricing? Thanks!