Bunnings heat transfer kits: Are they working?

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boland

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#271676 21-May-2020 21:02

We've got a new house (2014), insulated etc. It only has one heat pump though in the living room. The rooms are cold in winter, using portable heaters to heat them up, so using quite a bit of power and it's just annoying.

So, I was looking at installing two simple 2-room heat transfer kits to heat 4 rooms. Can't find any experiences about those kits online. Are those things really working?

Of course a HRV system or a proper central heating system is better, but that's beyond our budget.

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#2488949 21-May-2020 21:12

It won't work unfortunately.

Heat transfer kits really only work effectively for fires. They rely on a fire heating the room up to a high temperature and then moving relatively low volumes of very hot air into cold rooms. You also have fairly significant losses moving the air through the cold ceiling cavity.

With a heat pump, even if it had the power to heat your whole house, it controls the room temperature and doesn't give you the very hot air you need.

boland

545 posts

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#2488953 21-May-2020 21:20

Handle9:

It won't work unfortunately.

Heat transfer kits really only work effectively for fires. They rely on a fire heating the room up to a high temperature and then moving relatively low volumes of very hot air into cold rooms. You also have fairly significant losses moving the air through the cold ceiling cavity.

With a heat pump, even if it had the power to heat your whole house, it controls the room temperature and doesn't give you the very hot air you need.

Ah, thanks, yeah makes sense.

Froglotion

208 posts

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#2489868 22-May-2020 22:40

Get some heatpump companies around for a look and see what they come up with. A second heatpump would easily sort it.

PANiCnz

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#2489934 23-May-2020 08:57

We have one and use it with a fire place, its great! But as already pointed out they're no good with a heatpump.

cyril7

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#2489946 23-May-2020 09:31

Hi, as others have said a heatpump is typically selected by heat production to cover a specific volume, the installer of you current heatpump would have calculated the main living area volume and added in a couple of factors such as glazing loss etc and installed a machine to suit.

If you now start moving that heat away from the original volume (ie enlarging that volume beyond its production ability) the machine will start to work overtime and eventually will fail to heat anything. when you heavily load a heat pump (ie give it no time to cycle rest) it will ice up and production will tail off or stop all together

Cyril

Elmoz

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#2489952 23-May-2020 09:43

Like OP we have a new house with just a heat pump in the open plan lounge, dining, kitchen and were using oil heaters to heat the bedroom side of the house which was expensive. We looked at all the options (heat transfer, wall panels, single heat pump in hallway to spill the hot air etc) and eventually went with the extreme option of putting heat pumps in all the bedrooms. All back to back hi wall individually controlled (Wi-Fi) heat pumps so that we could all be happy and control the heat/cold individually. Shopped around, got a good deal and power bills have been lower as they are controlled better than the oil heaters. Yes it cost us a bit at the time but haven’t regretted it at all. I’m guessing it will pay off eventually but it is nice to go to bed in a warm room and have the timer come on in the morning to warm up the rooms as well.

Froglotion

208 posts

Master Geek

#2489965 23-May-2020 10:12

At that point a ducted system will be a better solution.

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Gordy7

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#2489971 23-May-2020 10:44

Handle9:

It won't work unfortunately.

Heat transfer kits really only work effectively for fires. They rely on a fire heating the room up to a high temperature and then moving relatively low volumes of very hot air into cold rooms. You also have fairly significant losses moving the air through the cold ceiling cavity.

With a heat pump, even if it had the power to heat your whole house, it controls the room temperature and doesn't give you the very hot air you need.

I have to disagree.

I have a Weiss fan assisted heat transfer system, similar to the one illustrated in the Bunnings link by the OP.

While the heat pump (8.5kW) I have is more than adequate for the living area, using the heat transfer system moves enough warm air to my 3 bedrooms to remove the cold air.

Of course, while the temperature in the living area remains controlled by the heat pump, aditional heating may be required in the bed rooms if they are to be used as additional living areas.

Gordy

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boland

545 posts

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#2489976 23-May-2020 11:02

Think our best option is to install heat pumps in every room, like @Elmoz but my problem is that we don't know how long we'll be living in this house, we may move within 5 years. So based on ROI it doesn't make sense to go for that option, buying some electric heaters is cheaper short term.

It's only for May/June/July, in other months it's warm enough.

richms

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#2489987 23-May-2020 11:54

The savings of aircon for heating in bedrooms is pretty minor if you are well insulated. Perhaps first off just look at getting some smart sockets for the oil heaters to turn them on and off with a timer to see what that saves you?

Richard rich.ms

Froglotion

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#2490042 23-May-2020 12:51

boland:

Think our best option is to install heat pumps in every room

How do you figure that one out? I mean compared to a single ducted unit.

Place must be huge if a single heatpump in the hallway won't heat the rooms.

Batwing

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#2490066 23-May-2020 14:21

Using homeassistant and cheap xiaomi bt temperature sensors and switches actually saved us money last winter when compared to manually switching oil column heaters off and on. Probably take 2 years to pay the kit off in power alone not factoring convenience.

Similar in that our heatpump does literally nothing for half the house

Handle9

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#2490071 23-May-2020 14:52

Froglotion:
At that point a ducted system will be a better solution.

Less obtrusive perhaps but it won't give you better temperature control. Having a unit in each room gives you control of each room.

If you have one side of the house with high solar gain and the other having no sun you can have all sorts of control issues with a ducted unit. Ducted units have their place but it's not a one size fits all solution.

boland

545 posts

Ultimate Geek

#2490082 23-May-2020 16:06

Froglotion:

boland:

Think our best option is to install heat pumps in every room

How do you figure that one out? I mean compared to a single ducted unit.

Place must be huge if a single heatpump in the hallway won't heat the rooms.

Sorry, meant a ducted solution indeed. So, one extra heat pump for the bedrooms.

Froglotion

208 posts

Master Geek

#2490088 23-May-2020 16:17

If you need each bedroom at a different temperature, then I assume you'll also keep the doors shut?

I have my whole house sitting at 23 degrees if it's cold. I've never felt the need to have different rooms at different temperatures. I also never shut any bedroom doors as fresh air will prevent moisture becoming trapped. You'll also get weird temperature differences when walking from a room to the hall which will be a different temperature.

I'm not sure what the control issues you speak of are. I've had my unit 4 years and not experienced any. I can run the fan only mode for minimal cost which will circulate all air in the house. This eliminates having areas that are warmer than others by way of solar gain.

By the time you buy 3-4 seperate units, and have to control them all individually (since you are suggesting different temperatures in each room). You could get something like a Sleep ducted unit which will cover all bedrooms with a single round vent in the ceiling. No heatpump unit noise from the fan operating.

I've never seen a new build with a heatpump in every bedroom, but ducted systems have become super popular. They offer much better versatility. Fresh air intake if wanted, zoning, wifi control.

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