First Fix Plumbing Decisions

bull987654321

Hello,
I am building a 2 storey block house. I am currently getting ready for plastering inside. I have some wiring and plumbing done. I am putting in a heat recovery system and will be airtightening the house as much as possible.

I need some advice on a few issues.

1. Plumbing system pressurised or not? I am putting in a normal heating system with radiators and an oil fired boiler outside the house. I was planning on putting the boiler in the garage which would mean about 7 metres of pipe under the ground outside. But now I thinking that the heat loss would be too much, even with the insulated underground piping that can be used. I am now thinking of putting the burner on the footpath just where the pipes exit the house.

2. I am putting 3 showers in the house. I was thinking of putting an electric in the downstairs bathroom. I was thinking of putting 2 mixer showers upstairs in the ensuite and the main bathroom. I have put plywood up on the bathroom wall studs as I heard it was better to tile on than a hardwall on slab finish. Would I be better to get the mixer heads at this stage and install them before I slab the other side of the walls. Is a pump normally needed in the hotpress for these mixer showers.
What shower and pump would be recommended for this setup.

As regards the pressurised vs non pressurised, I have good height in my attic to put tanks up high and get a good head pressure.
What system would you suggest or what are the advantages of each system.

3. I am putting 2 stoves in the house also. One may heat water and the other will be just a standard stove. The chimneys are on the internal of the house and I have no external air supply yet for these. I am going to run
a 3" pipe up the side of my chimneys into the attic to draw the external air from here. I think a normal PVC pipe is OK to run up the chimney and also through the side of the chimney wall to the side of the stove. This will then be joined to the external air pipe supplied with the stove. Should I be using a fire resistant type pipe through the chimney side wall or would it be ok to use the normal PVC pipe in this area.

The size of the stove for heating the water is probably going to be 5 kW. that would be around 3 for the room and 2 for the water. The room size is about 5m x 4mx 9 feet. I dont want the room boiling by oversizing the stove for heating the water. I was thinking of putting a 8000 btu boiler on the stove. I think it would be better to run the stove flat out and struggle to heat the room than trying to damp it down to avoid overheating.

L1979

Hey Bull,

Just a couple of quick comments.

1. Pressurised system has slightly more complicated plumbing and control requirements, but will provide an excellent shower.
Gravity fed with Boost pump in hotpress is a less complicated and expensive system to install, which would provide comparable results.
In saying that i opted for a pressurised system and am very satisfied with results.

2. Don't forget to PVA marine ply before tiling!
I would install showver valves and before slabbing at rear. Also, perform a final pressure leak test, to ensure leak tight, before closing the cavity (learnt this the hard way)
WIth a gravity system you can have a twin propellor boost pump anywhere after the water cyclinder(hotpress).
With a pressurised system you would have a boost pump before the cyclinder (attic).

3. Am i right in saying that you cannot have a stove for DHW in a pressurised system (As it is not a regulated heat souce), or are there controls that can be added to facilitate this?

Galway Elvis

bull987654321 wrote: »

Hello,
I am building a 2 storey block house. I am currently getting ready for plastering inside. I have some wiring and plumbing done. I am putting in a heat recovery system and will be airtightening the house as much as possible.

If you dont seal up your house entirely the HR system will never work to optimum. This is much easier do when the the entire house is block and concrete. I put Bio-Foam between the rafters to seal and insulate the top of the house. Great job but not cheap.

Is the system installed fully prior to plastering?

I installed my own system, took my time to figure the routing for the ducts, bonded, sealed and insulated all the joints properly. The biggest lesson I learned was how easy it is to put one in badly. There are a lot of cowboys out there installing HR systems. While it is not difficult to get a system going, if it is installed badly you will never get the volume and balance of air circulation right. Then you will have much bigger problems, dampness, carbonmonoxide buildup and a lot of money wasted.

maradonas

good luck with that im goin for a pint

Livelong

I am at same stage have a 2 story house and deciding to to put in a pressurized system or a tank in the attic what is the disadvantage and advantage with each of them