Ducted Heat Pump Recommendation in Waipa (Waikato)

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#3075464 12-May-2023 14:19

Quinny:

I'm still happy with my 9-year-old multi-system as I have 4 heat pumps with it (lounge, master bedroom, study, dining/2nd lounge). If doing now, I would add wi-fi options, but still hoping to retrofit that anyway just Daiken ones are not cheap. It lets me heat where and when I want. As others have said depends on the age of the home, insulation, and size of rooms. But I do think its worth looking at.

My wife doesn't like the ducted system. She'd rather have high walls for simplicity.

I have a Broadlink RM Pro 4controlling my 12 year old Daikin, which works from the Broadlink app or Home Assistant. It takes a bit more work in Home Assistant, programming the keypresses from the remote, though someone may have already done it for your model of heat pump which makes it easy. You need line of sight from the device to the heat pump for the IR signal, but they're cheap and work quite well. There's no feedback like with WiFi, so if the remote is used to change the temperature HA / apps are not updated like my newer ones do. I can live with that given the price. There's also an RM mini model which is smaller and cheaper.

rb99

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#3075481 12-May-2023 14:58

billgates:

If we leave the Lossnay powered OFF today then we will use less power as the ducted aircon will not have to fight for 5 degrees tempurature difference between it set to 20 degrees and Lossnay only returning 15 degrees re-circulated heat. I will post the results tomorrow of my findings.

I know i'm not exactly Einstein, but I don't really get this. I presume Heatpump and Lossnay talk to each other ? If the Lossnay is 15 doesn't the heatpump only have to top up by 5 to 20. Are you saying if the Lossnay is on all the time, providing 15, the heatpump is trying to top up to 20 all the time. But wouldn't there be some automatic setting to, I dunno, tell the Lossnay to turn itself off if the air its providing is making the heatpump work unnecessarily ?

Me and thinking really don't get on 😀

“The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness.” -John Kenneth Galbraith

rb99

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#3075500 12-May-2023 16:04

rb99:

I know i'm not exactly Einstein, but I don't really get this. I presume Heatpump and Lossnay talk to each other ? If the Lossnay is 15 doesn't the heatpump only have to top up by 5 to 20. Are you saying if the Lossnay is on all the time, providing 15, the heatpump is trying to top up to 20 all the time. But wouldn't there be some automatic setting to, I dunno, tell the Lossnay to turn itself off if the air its providing is making the heatpump work unnecessarily ?

Me and thinking really don't get on 😀

They do talk to each other, but Lossnay will not turn OFF its functions that you have set it to regardless of what the ducted aircon is doing. If the return air from Lossnay is only 15 degrees and ducted aircon is set to 20 degrees then eventually that 15 degrees return air will mix with the 20 degrees air from ducted aircon and temperature will get lower and thus ducted aircon will use more power to keep up with 20 degrees tempurature its been told to set the room to. Remember that the return air from Lossnay cannot be controlled or set by you. It's the heat exchanger trying to extract as much heat it can from the stale air leaving your home to go outside so clearly there is a 5 degrees loss from 20 degrees stale air going through the heat exchanger and heat exchanger in Lossnay being able to recoup 15 degrees back while outside is 8 degrees.

Do whatever you want to do man.

Paul1977

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#3075507 12-May-2023 16:36

We have a Mitsi Ducted system with AirTouch zone control and a Lossnay.

When not actively heating or cooling we have the heatpump on "fan only" to keep the fresh air from the Lossnay circulating (the Lossnay outputs into the heatpump intake, so can't run the Lossnay without the heat pump going).

The Lossnay uses very little power, and the heat pump uses very little when on "fan only". But when actively heating or cooling a ducted heat pump can be very expensive to run. For me the fact that it's silent and heats/cools the entire house is worth the trade-off of higher running costs.

tweake

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#3075509 12-May-2023 16:45

billgates:

We leave the ducted air conditioning running 24/7, 365 days a year unless we go on a holiday in which case, we turn off the ducted air conditioning and turn ON the Lossnay so house is ventilated at least. We only really use the Lossnay during winters and that too mostly at night unless we need to bring down the temperature inside home while heating is running as sometimes then house can get too hot so fresh air from outside mixed with heated air, brings the right comfort level. There is always someone in our home during the day. We opted to not go with a zone control system to keep every room in the home at even tempurature so when you walk in, it's comfortable.

If we leave the Lossnay powered OFF today then we will use less power as the ducted aircon will not have to fight for 5 degrees tempurature difference between it set to 20 degrees and Lossnay only returning 15 degrees re-circulated heat. I will post the results tomorrow of my findings.

thats really poor. the lossnay system is meant to be used opposite to the way your using it. its meant to be running constantly, its ventilation and you always need ventilation. however when your away on holiday, there is no need for ventilation in the house so it can be turned off.

the amount of power used to heat the small amount of ventilation air is absolutely tiny with that system. its not worth even bothering with.

now the other factor is ERV's (lossnay) typically require a dehumidifier to be used along side. they keep moisture in a house, just like not having ventilation running keeps moisture in a house. i hope you have a humidity gauge in the house.

Paul1977

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#3075511 12-May-2023 16:51

rb99:

I know i'm not exactly Einstein, but I don't really get this. I presume Heatpump and Lossnay talk to each other ? If the Lossnay is 15 doesn't the heatpump only have to top up by 5 to 20. Are you saying if the Lossnay is on all the time, providing 15, the heatpump is trying to top up to 20 all the time. But wouldn't there be some automatic setting to, I dunno, tell the Lossnay to turn itself off if the air its providing is making the heatpump work unnecessarily ?

Me and thinking really don't get on 😀

The purpose of the Lossnay is to provide fresh air. It will make the heat pump work a little harder at times, but if you turn it off it kind of defeats the purpose of having it.

Also note that the throughput of the Lossnay is way lower than the ducted heat pump, so most of the air going through the heat pump is recycled.

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#3075559 12-May-2023 17:01

tweake:

now the other factor is ERV's (lossnay) typically require a dehumidifier to be used along side. they keep moisture in a house, just like not having ventilation running keeps moisture in a house. i hope you have a humidity gauge in the house.

Not quite true.

Lossnay do ERV (commercial range) and HRV (residential range), and HRV models do remove moisture.

When I built there was only one HRV Lossnay model and it had a very small capacity so installers advised to put in a commercial ERV model, but it was never explained to me that it didn't remove moisture. I only learned the difference recently, and was quite disappointed when I found out. I think @billgates is in the same boat as he has the same model Lossnay as me, did your installers explain this to you at the time @billgates?

Lossnay now have HRV residential models in a much larger capacity than when I purchased.

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tweake

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#3075565 12-May-2023 17:23

Paul1977:

tweake:

now the other factor is ERV's (lossnay) typically require a dehumidifier to be used along side. they keep moisture in a house, just like not having ventilation running keeps moisture in a house. i hope you have a humidity gauge in the house.

Not quite true.

Lossnay do ERV (commercial range) and HRV (residential range), and HRV models do remove moisture.

When I built there was only one HRV Lossnay model and it had a very small capacity so installers advised to put in a commercial ERV model, but it was never explained to me that it didn't remove moisture. I only learned the difference recently, and was quite disappointed when I found out. I think @billgates is in the same boat as he has the same model Lossnay as me, did your installers explain this to you at the time @billgates?

Lossnay now have HRV residential models in a much larger capacity than when I purchased.

while its been a while, i have not seen any info to say they are HRV. hold on, i just googled it to check and it looks like HRV cores are a new item. so thanks for the update.

considering how many hack install jobs i've heard of, i don't think the installers would even know, or even care.

rb99

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#3075567 12-May-2023 17:27

Thanks for the explanations everyone. Confusion is, if not eliminated, significantly reduced.

What's this about humidity ? If we get we wouldn't need heatpump and Lossnay and dehumidifier ? I thought (and read on their website) one of the main reasons for Lossnay is fixing wet windows.

and HRV, I though the HRV company wasn't held in high regard in these circles ?

“The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness.” -John Kenneth Galbraith

rb99

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#3075571 12-May-2023 17:44

Paul1977:

When not actively heating or cooling we have the heatpump on "fan only" to keep the fresh air from the Lossnay circulating (the Lossnay outputs into the heatpump intake, so can't run the Lossnay without the heat pump going).

The Lossnay uses very little power, and the heat pump uses very little when on "fan only". But when actively heating or cooling a ducted heat pump can be very expensive to run. For me the fact that it's silent and heats/cools the entire house is worth the trade-off of higher running costs.

Lossnay feeds into heatpump feed. Is that standard ? Isn't Lossnay independent with its own fans ? You have two sets of fans running ?

“The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness.” -John Kenneth Galbraith

rb99

tweake

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#3075574 12-May-2023 17:57

rb99:

Thanks for the explanations everyone. Confusion is, if not eliminated, significantly reduced.

What's this about humidity ? If we get we wouldn't need heatpump and Lossnay and dehumidifier ? I thought (and read on their website) one of the main reasons for Lossnay is fixing wet windows.

and HRV, I though the HRV company wasn't held in high regard in these circles ?

the nz market is full of BS. hrv company is not the hrv system we are talking about.

the basics, you need ventilation. either windows (which is poor) or mechanical (fan) ventilation. mech ventilation can be positive pressure for your typical air leaky house. however if you house is air tight enough it can be worth having a balanced system (like lossnay). of which you can get HRV or ERV cores. HRV keeps heat in, ERV keeps heat and moisture in.

wet windows, its not exactly as the media say it is. even with double glazing and a dry house you can get wet windows if its cold enough outside (double glazing is not as good as people think it is). the real thing your chasing is control of interior humidity, not trying to dry windows.

best possibly way is ERV with dehumidifier. i think there is one company that sells a ventilation system with a built in dehumidifier, but there is others that can connect to a ducted system. but you really want a decent air tight house for it to work well.

the other is if the house is not that air tight, you can get away with more budget options with a few caveats. an HRV core will push take moisture out, but it will also bring moisture in. so in high outdoor humidity your home humidity will go high, the advantage is you retain some of the heating. you can use ERV but your using the air leakage to dry the house, but that also reduces the effectiveness of an erv. so its a bit of a hack job.

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#3075575 12-May-2023 18:03

rb99:

Lossnay feeds into heatpump feed. Is that standard ? Isn't Lossnay independent with its own fans ? You have two sets of fans running ?

can be both. if you do not have ducted heatpump it can be run on its own. however it would need its own ducting like all other ventilating systems.

but if you have heat pump ducting, why not just join the two and save a lot of ductwork. thats why lossnay is made to integrate with their ducted heatpumps. that does mean having 3 fans running. two lossnay fans (intake and exhaust) and the heat pump fan to circulate around the house.

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#3075576 12-May-2023 18:18

Our 80's house is far from airtight. Think Lossnay would still be a good idea ? Couldn't make things worse (I presume)...

“The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness.” -John Kenneth Galbraith

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#3075580 12-May-2023 18:32

rb99:

Our 80's house is far from airtight. Think Lossnay would still be a good idea ? Couldn't make things worse (I presume)...

imho complete and utter waste of money. just use a positive pressure system.

to be fair, its not impossible, just unlikely its air tight enough especially with original windows. its a maybe if its been extensively renovated, ie new gib, new windows/doors and especially new lights. even then wack a few holes in for plumbing and there goes the air tightness.

even on a new standard build its doubt full, but possibly worth testing to find out. you really have to build houses with the intention to be air tight for them to be air tight.

rb99

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#3075586 12-May-2023 19:06

So maybe some kind of positive pressure ventilation, preferably with a heat exchanger, like I think Smartvent.

And seperate heat pump, hopefully ducted ?

“The modern conservative is engaged in one of man's oldest exercises in moral philosophy; that is, the search for a superior moral justification for selfishness.” -John Kenneth Galbraith

rb99

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