Considering DIY'ing a Brivis Ducted Heater - 2007/09/19 17:43Hi,
First off - Great site!
I'm currently obtaining quotes from local companies (in Hobart, Tas) but frankly am disgusted with the pathetic service I've received from them so far. Imagine my surprise when I found your site and realised that the local mobs are not only providing poor service, but are offering completely uncompetative prices as well!
I am looking to go with a Brivis MPS HE 20kw model (~16.5 square, 3.5 bedroom, one storey house), and I'm confident that with the right information, I can install this system myself (so would be purchasing one of the pre-packaged DIT ducting kits... what a great idea, by the way!).
For my house, under-floor access is excellent (ie ~1.5m height under most of the house), and in-roof ducting is not an option as much of the roof is a suspended cement slab.
I noticed that you recommend the roof DIY kit for an internal heater, and an under-floor DIY kit for the external unit, which maybe suggests I should be getting an external heater unit for the under-floor installation at my place.
I have a garage area under the house with a large (otherwise unusable) area off to the side (still under the floor) that would be an ideal spot to sit the heater unit.
However, given the ease of access to this area I'm unsure if I should be using an external unit instead of the recommended internal unit. I presume the difference b/w the two is that external unit is safer to touch and hence should be used in areas that are easily accessible (can you pls confirm the difference?).
I note also that the Brivis brochure indicates that the internal and external units have slightly different airflow. Is a higher airflow better or worse?
Are you able to advise which unit I should be using?
Further to this, I understand that a metal flue is not required, and that PVC tubing is ok to use with the 5 star MPS systems. Can you confirm this?
Does the manual/dvd provide instructions regarding how to install the flue and drain (eg maximum flue length, correct diameters, allowed elbows, etc)?
Thank you for your time! I look forward to doing business with you!
Best regards, Ben Roberts.
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cyril
Admin Admin
Posts: 9
Re:Considering DIY'ing a Brivis Ducted Heater - 2007/09/20 16:19External heaters should be used externally. If you are putting the unit under the house and have the room, you should use an internal, the flue must discharge outside the house, not underneath.
Airflow is irrelevant in your case. Internals have a little more air to help blow the air down from the ceiling to the floor. It wont heat the place any faster/slower.
Sounds like you should be using an internal heater under the house, with a under-floor DIY kit.
You are correct, the Brivis 5 star HE series requires a 50mm PVC flue, not metal.
Our CD-rom explains how to run all the ducting etc. The heater has instructions on how to run the flue and drain, please find the tech data below:
(I hope this answers all your questions - good luck)
Brivis Technical Data Type: Heater Date Updated: Category: MPS HE 20e, MPS HE 20i, MPS HE 30e, MPS HE 30i Subject: Maximum Flue Length
The flue connection to the HE unit is 50mm Drain Waste and Vent Pipe (DWV to AS/NZS 1260) and must be installed in accordance with the following.
The flue must discharge externally in a vertically up position and be fitted with a Vent Cowl (DWV to AS/NZS 1260). The clearances required are the same as those applying to a balanced flue as per the AG 601 installation code. Seal all joints.
The minimum pipe length is 1.2M for 50mm DWV flue systems. The maximum length of 50mm DWV flue pipe is dependant on the number of bends incorporated in the flue system as per the following table (maximum 4 bends). Note: 45o bend = 1/2 X 90o bend. Bends 0 0.5 1 1.5 2 2.5 3 3.5 4 Flue (M) 10 9.25 8.5 7.75 7 6.25 5.5 4.75 4
Alternatively, a 65mm DWV flue pipe system may be installed as follows: The minimum pipe length for 65mm DWV flue systems is 4M. The maximum pipe length for 65mm DWV flue systems is 20M and can include up to 6 bends.
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sepster
User Junior Poster
Posts: 8
Re:Considering DIY'ing a Brivis Ducted Heater - 2007/09/20 18:46Hi Cyril,
Thanks for the detailed answers.
With regard to "clearences... as per the AG 601 Installation Code" and "AS/NZS 1260"..
Is this information available as part of the kit?
I'm hoping to sit the heating unit pretty much directly below the wardrobe that will be used for return air grille (I'll be using some excess return air ducting to ensure a minimum three meter loop between the return air duct and the unit to minimize noise through the r/a grille). Can you see a problem with this?
I'm hoping to run the flue up through the back of this same wardrobe, up out through the ceiling and tiled roof. Is there any reason why the flue shouldn't go near the r/a box?
Thanks again, Ben.
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cyril
Admin Admin
Posts: 9
Re:Considering DIY'ing a Brivis Ducted Heater - 2007/09/20 21:27I don't have copies of the AS standards, the plumber who connects the gas could also run those pipes for you.
Run six meters for the return air, it'll reduce the noise considerably.
That should be ok for the flue, but it would be easier to discharge it out the side of the house probably?
cyril
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sepster
User Junior Poster
Posts: 8
Re:Considering DIY'ing a Brivis Ducted Heater - 2007/09/22 17:00Hi Cyril,
OK yes, I'll run the full six meter length of duct for return air. Saves a cut! Does most of the noise travel up the duct?
Would it also be worth putting in some accoustic insulation under the floor (above where the heater sits)?
The flue will need to go up into the wardrobe at least, to get above a solid cement patio (outside the wall the heater will be adjacent to). I could then punch out the back of the wardrobe wall and out onto the back corner of the patio, but I figured straight up from there would be more elegant (and less elbows). But it will probably be easier to go out through the wall so that's probably what'll end up happenning!
Cheers, Ben.
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Mark
Admin Admin
Posts: 47
Re:Considering DIY'ing a Brivis Ducted Heater - 2007/09/25 03:47Hi Ben,
The fans on new ducted heating units are very quite. However when you run less than 6m of duct you will often get some noise of the fan transferring along, better to run the 6m and then what minimal noise is there will be lost in the duct.
Don't bother with sound proofing above the heater unless its right under a bedroom. Even then it depends on how fussy the bedrooms owner is
What your doing with the flue sounds ok to me btw.
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sepster
User Junior Poster
Posts: 8
Re:Considering DIY'ing a Brivis Ducted Heater - 2007/09/27 05:07Thanks for all your help and excellent service to date guys - I'll be recommending you to anyone who asks me about our new heating system! (Natural Gas is very new here in Hobart... so plenty of people I know are going this way).
Ok - so I've ordered the system and apparently it'll arrive early next week...
But in the mean time, I've another question that can't wait until I get the instructions with the kit!
One of our rooms is going to be re-carpeted this week, and I've ripped up the old carpet, exposing the 100mm tassie oak floorboards.
I'm wondering if I should cut the floor register hole into the boards before the carpet is laid. Is there any advantage in doing this? I thought maybe if the hole was already there, the carpet layers might smoothedge (or glue?) the carpet down around the hole?
If they just lay the carpet over the hole then take to it with a knife, I won't bother pre-cutting as I can just wait for the instructions. But if I should pre-cut the floor, can you give me the exact dimensions I need for the size of the hole? I realise the registers are 300x100mm, but I presume the hole also needs to be a bit bigger than the register to cater for the edge thickness of the boot?
Further to this, and regardless of whether I cut before or after carpeting, I mentioned previously I have 100m floorboards (or probably the imperial equivalent). If I'm cutting a register that runs lengthways along a board, and if I only need a 300x100mm hole, would I be better off a) just taking a 300mm section out of one board, or b) should I cut half way into two parallel boards?
I guess a) means less "damage" to the original floorboards, easier to repair if register is moved, but would mean the board no longer runs the whole length of the room.
While b) would (i think) give the overall floor more strength because both boards would still run the entire length of the room.
We may want to expose and polish these boards later, so the cosmetics of it are an issue as well....
How would you guys approach this?
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Mark
Admin Admin
Posts: 47
Re:Considering DIY'ing a Brivis Ducted Heater - 2007/09/28 05:06Thanks for the order - all the best with the installation.
I would cut the holes before the carpet goes down for a few reasons:
1 - you can see where the joists are with a timber floor (makes life a little easier) 2 - you won't have to risk damaging your new carpet
Cut the hole 306mm x 106mm to allow for the boot thickness. Test it when the kit arrives to ensure a snug fit with the register.
With the cutting - it doesn't really matter where - just make sure you have the room underneath and your not going to cut a hole above a joist, bearer, sewer pipe, gas line, water pipe etc etc etc
If it was my place, i'd be more interested in the distance off the window so curtains aren't affected and it looks good in that position - no one is going to notice if half or a full floor board is cut... (just my humble opinion)
(makes life a little easier)