Heat Transfer System - Limited impact

Forums › Home Workshop DIY › Heat Transfer System - Limited impact

1 | 2

tweake

2391 posts

Uber Geek

#3076668 16-May-2023 10:22

SomeoneSomewhere:

Heat transfer systems often have pathetic little 150mm fans delivering perhaps 100l/s or less. It's very much dependant on the fan size.

depends on the actual fan. i've used plenty of 150mm fans that are a tornado in the house. they can put out more than enough flow. it just depends on the fan and how its setup. many 200mm fans are the same fan with bigger inlet/outlets.

tweake

2391 posts

Uber Geek

#3076678 16-May-2023 10:33

timmmay:
Jase2985:

reverse the fan, have the cold air being exhausted above the fire, it will heat quickly and you likely wont notice it, and as the cooler air is sucked out the rooms it should suck the warmer air from near the fire and heat the rest of the house.

But 150mm is small for a 4 duct system.

I'm not sure that will work. Most houses aren't sealed, it could just suck more cold air in from outside. For it to work the warmer air up high would need to be pushed into the bedrooms at floor level.

I suspect pushing warm air in through decent diffusers is probably more likely to work.

agree. it will suck in some cold air into the bedroom from outside and suck in cool air from the hallway. it has to heat the hallway up first and suck in air from every room connected to the hallway. plus it will push out the hottest air out of the lounge (typically ceiling height air). so at best its loose heat, heat up part of the house you don't care about and not heat up the bedrooms very well.

there is good reason i have never heard of anyone in the world running hvac that way.

tweake

2391 posts

Uber Geek

#3076681 16-May-2023 10:39

jm3:

We have a 3 room simx transfer system with the 0.6R insulated ducting. It is hard to heat up the rooms without making the lounge sweltering but it does help take the chill off as the night cools. Here are some stats from the other night when we had the fire and transfer system running from around 5pm until 8:30pm. We usually turn the transfer off when kids are sleeping.

Does anyone else have some stats for comparison?

actually thats not to bad. i've heard of much worse.

you will get lag between lounge getting hot and bedroom heating up. if its a temp controlled fan then i would expect some temp bounce as the lounge heats up, fans pulls out hot air, sucking in cold air and cooling down the lounge.

you have to keep in mind that your using a fireplace thats meant to heat one room, to heat almost the entire house.

MadEngineer

4291 posts

Uber Geek

Trusted

#3076782 16-May-2023 13:48

Is he using a fireplace though?

Our wood burner is 23kw and rated for a home over 150m^3.

28°c in a lounge is huge. I’m stripping off at 25.

You're not on Atlantis anymore, Duncan Idaho.

neb

11294 posts

Uber Geek

Trusted

Lifetime subscriber

#3076877 16-May-2023 15:54

timmmay:
Interesting. I don't know what brand I have, whatever the installers used.

Probably better than what was at the Casa, which was "whatever was cheapest at the DIY store". It was just alu foil with some sort of backing wrapped around coiled steel wire, I don't know how the previous owners didn't notice that the temperature in it dropped to barely above the destination room temperature as it moved the air the full length of the roof space.

timmmay

20581 posts

Uber Geek

Trusted

Lifetime subscriber

#3076882 16-May-2023 16:23

neb:
timmmay:

Interesting. I don't know what brand I have, whatever the installers used.

Probably better than what was at the Casa, which was "whatever was cheapest at the DIY store". It was just alu foil with some sort of backing wrapped around coiled steel wire, I don't know how the previous owners didn't notice that the temperature in it dropped to barely above the destination room temperature as it moved the air the full length of the roof space.

Mine is definitely specified as R1.0, and I saw it was insulated silver ducting.

mattenz

190 posts

Master Geek

#3076892 16-May-2023 17:44

Start by measuring temperature at the inlet and outlets, then go from there.

Sharesies

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

andrew75

145 posts

Master Geek

ID Verified

#3078123 20-May-2023 20:01

Just measured some metrics on my system.

Outside temp 15.5

Temp at fire room intake 37.7-38.0

Temp at outlet at most distant room (20 meter+ run) 37.5-37.6

Temp in most distant room (small bedroom) 25

Bearing in mind also we have pretty crap curtains from an insulation perspective.

Have the 200mm fan running at about 3/4 speed.

McNotty

4 posts

Wannabe Geek

#3083913 2-Jun-2023 13:13

Gidday,

With an inbuilt I'd have the inlet within a meter of the fire place front. We've got three room Simex kit with R 1.0 ducting and it makes a world of difference to our house.

Our fire is probably oversized (Masport R5000) for our house 140 sqm, but with the heat transfer the whole house sits nicely at 21-22 degrees even on a cold night.

Maybe look at upgrading to a 200 mm kit with good insulation.

1 | 2