Heat transfer control question

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JayADee

2148 posts

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#296175 26-May-2022 21:36

Hi,

Does the heat transfer controller turn the fan on based on the temperature in the room with the fire or based on the room you are heating? And which room does the controller go in?

I'm hoping the room with the fire as I want to regulate the lounge the odd time it gets hot and it's a bonus we can crank the fire up a bit to heat the back of the house.

Also, are the fans usually suspended above the ceiling or are they fixed to a ceiling beam?

Thanks!

ps looking at a single room kit and getting the r 1.0 (why isn’t it available higher?) ducting. Thought I'd get a couple quotes for someone to do it, we're not much up to mucking about in the roof anymore but I'll pick where the inlet and outlet go. I've got BrightR coming next month for a quote and will ask a local electrical co. for one as well. I know the kit with r .6 ducting is about $370 Not sure what labour will be but I have an easy roof space to work in.

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1530 posts

Uber Geek

#2919187 26-May-2022 21:39

Controller goes in the room with the fire. The idea is to heat that room and then send the excess heat to another room or rooms.

JayADee

2148 posts

Uber Geek

#2919189 26-May-2022 21:42

k1w1k1d:

Controller goes in the room with the fire. The idea is to heat that room and then send the excess heat to another room or rooms.

Awesome. Thanks.

Are the fans installed suspended or on a beam?

Wheelbarrow01

1726 posts

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Chorus

#2919197 26-May-2022 22:12

The one I bought (but haven't installed yet) is supposed to be suspended and from memory it has some supersized cable ties supplied for this purpose. The reason being that this reduces the chances of unwanted vibration/noise.

JayADee

2148 posts

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#2919198 26-May-2022 22:17

Thanks. :)

andrew75

145 posts

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#2919201 26-May-2022 22:23

Make sure the ducting is insulated the more the better. Huge heat losses without insulation esp over long distances. I wrapped my ducting with extra insulation from memory a R1.9 blanket (on top of either R0.6 or 1 ducting I cant remember). Makes a massive difference and now a measure effectively zero heat loss despite a >20m run from one end of the house to the other. And bigger diameter ducting = more airflow - I went with 200mm throughout.

JayADee

2148 posts

Uber Geek

#2919876 28-May-2022 22:39

I'll probably end up with r 1.0, 150mm. I don’t think I'm up to climbing around in the roof anymore so I'll be getting a kit install unless I can get the installer to add some extra insulation like you did.

k1w1k1d

1530 posts

Uber Geek

#2919905 29-May-2022 09:36

We have a wood burner in the living room, so I installed a three bedroom heat transfer unit with 150mm duct to transfer excess heat to the bedrooms.

I was very disappointed with the airflow to the bedrooms. I hung a piece of cotton from the outlets to see if it was actually working. The cotton pieces don't move much.

It was lucky to raise the bedroom temperature by 1C after a couple of hours running.

The fan had heaps of flow in open air or with just one 3m length of duct, but by the time the whole system was installed the airflow was hopeless. Inlet-3m-fan-3m-splitter-3m-outlets.

I would never have gone to the trouble of fitting it if I had assembled the system on the floor to see how it worked.

I have been advised that 150mm duct has too much resistance and should have fitted a unit with 200mm duct. I have considered fitting an extra fan directly in front of the splitter to give the airflow a boost, but have given up on this at the moment.

I have also considered modifying the system to a DVS type system.

Sharesies

Trade NZ and US shares and funds with Sharesies (affiliate link).

JayADee

2148 posts

Uber Geek

#2920255 30-May-2022 06:39

Thanks for sharing your experience, that's got to be annoying!
The simx three room kits all come with 200mm ducting, the 2 room and 1 room come with 150. Their 2 and 3 room kits also come with a two speed fan and I'm guessing it moves a bigger volume as well. I guess for my single room I'll have to make sure the ducting is stretched out to eliminate some of the corrugating.

Here's a chart of their kits from the BrightR web site:

https://www.brightr.co.nz/media/documents/SIMXHeatTrans.pdf

PANiCnz

990 posts

Ultimate Geek

#2920277 30-May-2022 08:18

We've got the simx three room kit installed, it's great!

SATTV

1649 posts

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#2920292 30-May-2022 09:11

My inlaws moved into a new house ( to them ) around 2001, it had a ceiling fan in the lounge also a wood burner and my MIL hated it.

While waiting for the electrician (family relative so low on the pecking order to get jobs done ) someone touched the fan controller and the fan went on and could not be turned off.

As a result the hot air was circulated up to the bedrooms and they were considerably warmer, my MIL had the fan replaced and they use it all the time when the fire is going.

Would a ceiling fan work as it could heat the house?

I know enough to be dangerous

jm3

86 posts

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#2920301 30-May-2022 09:56

We've got the Simx 3 room too it's okay it definitely moves air I think we can tweak it more though.

Make sure you get the outlets placed exactly where you want them even if that means buying more ducting. We don't have a large house only 82sqm and the ducting length wasn't sufficient. The sparky installing was a friend and he'd put no thought into where the outlets should go e.g. not directly over a bed, not too close to the door. I directed him on where to put them but I imagine unattended installations can end up in some pretty bad places in some circumstances.

You need a path for the return air to go under a door if it's closed, I usually leave doors ajar but the draft will pull them closed if they are not open enough.

If the return path is blocked from closed doors and you don't have enough air from outside or elsewhere air will be pulled from the easiest place and for us that's the fireplace. So if the fire is shutdown with a larger log at the end of the night and we were to close the doors and the log started to smolder that smoke will get pulled out and through the system. Not very pleasant to wake up to in the middle of the night, it's manageable once you know it can happen.

JayADee

2148 posts

Uber Geek

#2920347 30-May-2022 12:39

SATTV:

My inlaws moved into a new house ( to them ) around 2001, it had a ceiling fan in the lounge also a wood burner and my MIL hated it.

While waiting for the electrician (family relative so low on the pecking order to get jobs done ) someone touched the fan controller and the fan went on and could not be turned off.

As a result the hot air was circulated up to the bedrooms and they were considerably warmer, my MIL had the fan replaced and they use it all the time when the fire is going.

Would a ceiling fan work as it could heat the house?

No. We have a cassett heat pump in the centre of the lounge ceiling where the fire is and hubby occasionally turns it on fan mode. It blows all the hot air down but that's all. The air really needs to be pumped to the back of the house.

The fire heats the whole front no problem (lounge, kitchen, 3 bedrooms because the fire's in the middle) but the air needs to travel down the hall to the toilet and turn right at the end of the hall to the bathroom and fourth bedroom. The toilet, bathroom and fourth bedroom are cold partly because they're on the south side, partly because they're too far for the fire warmth to reach and partly because they're tiled. Also the fourth bedroom has no underfloor insulation (joists, two layers of ply, tile underlay and tiles) and I doubt the toilet corridor does either due to poor access.

It's a short diagonal shot from the lounge to the fourth bedroom as the crow flies over the ceiling plaster though so a heat transfer should work well. It will also push warm air into the bathroom for a return journey to the lounge with any luck!

JayADee

2148 posts

Uber Geek

#2920352 30-May-2022 13:00

jm3:

We've got the Simx 3 room too it's okay it definitely moves air I think we can tweak it more though.

Make sure you get the outlets placed exactly where you want them even if that means buying more ducting. We don't have a large house only 82sqm and the ducting length wasn't sufficient. The sparky installing was a friend and he'd put no thought into where the outlets should go e.g. not directly over a bed, not too close to the door. I directed him on where to put them but I imagine unattended installations can end up in some pretty bad places in some circumstances.

You need a path for the return air to go under a door if it's closed, I usually leave doors ajar but the draft will pull them closed if they are not open enough.

If the return path is blocked from closed doors and you don't have enough air from outside or elsewhere air will be pulled from the easiest place and for us that's the fireplace. So if the fire is shutdown with a larger log at the end of the night and we were to close the doors and the log started to smolder that smoke will get pulled out and through the system. Not very pleasant to wake up to in the middle of the night, it's manageable once you know it can happen.

Thanks. I won't be leaving the placement of the vents to chance, I'll tell them where I want them. I'm going to put the inlet close enough to the fire to be in hot zone and far enough away to avoid the air stream being drawn down to the fire and to avoid sucking in smoke when the fire door is open. Probably a couple of metres from the flu oriented to the front of the fire . For the outlet I'm going to place it near the back quarter of the fourth bedroom/office not too far away from the bathroom door so warm air will hopefully be drawn through the bathroom. Added bonus that's the same end of the fourth bedroom/office as the high wall heat pump if turning that on fan mode to shove the air down seems useful.

We've been leaving all the doors open to let the fire heat as much as possible so no problems there. (Except when showering or leaving the bathroom windows open)

tweake

2397 posts

Uber Geek

#2921481 1-Jun-2022 16:14

JayADee:

Hi,

Does the heat transfer controller turn the fan on based on the temperature in the room with the fire or based on the room you are heating? And which room does the controller go in?

I'm hoping the room with the fire as I want to regulate the lounge the odd time it gets hot and it's a bonus we can crank the fire up a bit to heat the back of the house.

Also, are the fans usually suspended above the ceiling or are they fixed to a ceiling beam?

Thanks!

ps looking at a single room kit and getting the r 1.0 (why isn’t it available higher?) ducting. Thought I'd get a couple quotes for someone to do it, we're not much up to mucking about in the roof anymore but I'll pick where the inlet and outlet go. I've got BrightR coming next month for a quote and will ask a local electrical co. for one as well. I know the kit with r .6 ducting is about $370 Not sure what labour will be but I have an easy roof space to work in.

just a quick heads up.

you may have seen in the media stories about houses filling with smoke due to heat transfer systems which has the potential to kill you.

thats primarily caused by people not installing an air return and i've only seen one manufacture mention that you need to install one. common way is to undercut the bedroom and hallway doors. otherwise install jumper ducts. that makes it much more efficient and heats the hallway a tad as well.

the controllers turn the fan on when lounge gets to temp so excess goes to the other rooms.

try to put the outlet away from the door and windows as you can and the intake away from the fireplace a bit.

timmmay

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#2921493 1-Jun-2022 16:54

tweake:

try to put the outlet away from the door and windows as you can and the intake away from the fireplace a bit.

Wouldn't the intake be as close to directly above the fire as possible, in order to gather maximum heat for distribution?

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