Had a house built in 2000 in Canberra. It has a Brivis EMS20i central heater going to 7 outlets.
Ever since I moved in I have not been happy with the way that it heats the house. Until now it hasn't been too much of an issue, but now I have a wife and am planning a little one would like some help/advice on getting it right.
The house is 3 bedrooms and has a living area of around 110m2 plus double garage. The heater is a Brivis EMS20i (a model I believe that was short lived) mounted in the roof space with 7 outlets.
From the heater there is one run (think it's 350mm but might be more), it comes out of the heater then makes a reasonably short left turn. After about 3m it splits in two with a smaller run to the left (think 250mm) and continuing in the original size. The run to the left goes for about 3m where it splits again, with a 150mm branch going to the inside outlet in the lounge. This run doubles back a little bit. About 2m further on it splits again into two 150mm runs with one run feeding the outside outlet in the lounge and the other the outlet in bedroom 1.
Back to the main run, after the first branch it goes on in the same size for about 3m before having a 150mm branch to bedroom 2 (which doubles back a few m) then goes down in size before splitting again with a 150mm run to bedroom 3. It then goes further before splitting into two 150mm runs feed the two outlets in the dinning room.
Return wise the wardrobe in bedroom 2 has been partitioned off to provide a 600mmx600mm box which then feeds back to the heater. There is a 400x1000 filtered return grill on the lounge side and a 400x400 filtered return grill in the bedroom itself, put in by the builder after I first complained about issues with the heater. (didn't fix them clearly)
The controller is a Networker MK I mounted in the lounge above the return and just below one of the outlets.
A mud map of the house and the duct layout found in the link below.
http://members.ozemail.com.au/~ajwright ... 20runs.pdf
So, here is the issue. The two smaller bedrooms seem to be too hot. The dinning room and the kitchen are about right. With the lounge room the area closest to the return is pretty good but the area near the window is cold. I measured it and if the temp at 1500mm is 22' then at 600mm (about lounge height) the temp is about 19'. Bedroom 1 is similar but worse, because the temp is ok at 1500mm right under the outlet but anywhere else in the room, especially at bed height the whole room is freezing.
So what can I do to try and get even heat throughout the house at the low levels where we sit and sleep? My thoughts where I should fit a damper on the bedroom 2 and 3 runs to limit the airflow to 'cool' them down a bit. I have tried to do this using the butterfly damper adjustment on the outlet themselves but found doing so meant the airflow coming out wasn't even. My assumption is doing it inline will create an even flow out and will cool these rooms down a little plus provide more airflow to the other outlets.
I also reckon the controller is in the wrong place, because to me it seems as if the return is pulling hot air down from the outlet just above, which is clearly what it is meant to do, but in doing so it is creating a warm zone around the thermostat that is not representative of the rest of the room. By moving it elsewhere in the lounge I would think it would get a much truer reading of the temp and my guess is the heater will stay on longer allowing the warm air to get down. At present during normal running the heater only runs for a few minutes(3-5) before switching off for a similar time.
With bedroom 1 and the outlet in the lounge near the window I don't think they are getting enough air to get down to the living area's, but not sure how to fix them. All I can think is to make the fan speed higher, which I believe is possible to do on the EMS heaters. I have seen the menu's on the heater, but clearly have no idea what the settings do so haven't touched them. Does anyone have a service manual for the EMS or similar unit that might explain which setting is fan speed etc?
Of course I could call someone in and have them charge a motza and probably not fix it hence why I am sounding out the knowledgeable ones on this board for idea's that someone technical and mechanical minder such as myself could do first.