I wonder if anyone can advise me on some questions that I cannot find mentioned anywhere on the web for an simple wet UFH project.
I have just laid a 7-loop underfloor heating pipe system in my (very well insulated) small 3 floored 3 bed family Victorian house.
I intend to use a combi-condensing boiler, and run the boiler flow heating pipe first to two directly in-line conventional radiators. Then return th= at flow to the input manifold for the 4 underfloor heating loops for the wooden upper floors. (FYI =96 I have used old thin aluminium offset printin= g plates as spreader plates wrapped around the pipes!)
The upper floors' return manifold will then go to the input manifold of the= =20 concrete ground floor 3 heating loops. This ground floor return manifold will then return to back to the boiler!
I figure the radiators will initially lower the water temperature down for the wooden floor input manifold. Then this lowered return water will go into the concrete floor input manifold, which will then return to the boiler at a very cool temperature. Thus making a very efficient condensing system! (If not very tepid)
To save costs (and as an experiment!) am intending to construct the two set= s of manifolds with 22mm push-fit copper tee pipes (with 15mm reducers) and loca= te it under the ground floor staircase in cupboard, about 4m from the boile= r using 22mm insulated copper pipes.
I will balance each loop with gate valves (or any ideas?) on the return manifolds, using temporary temperature gauges clamped onto each retu= rn pipe to get even return temps. I will put stopcocks on the input valves = for isolation purposes.
I intend to only use the in-built boiler pump to circulate the heating, and use the in-built boiler water temperature thermostat and timer to control the room heating temperature.
I can will make allowances to retro- fit TRVs in each room if the room on t= he upper floor loops only If heating is uneven. But I intend to have the he= ating on in all rooms constantly from November to April
Q.1. Do I need to put in any Automatic Airbleed Valves on the upper storey loops, (If so where should the AAV be positioned -Just before the return pi= pe goes vertically down to the manifold to catch the air?)Or does the UFH w= ater have enough pressure force the bubbles down to the ground floor manifo= ld AAVs.
Q.2. Do I put AAV=92s on BOTH the inlet AND return manifolds, or just retur= ns?
Q3. Is this idea workable? If so can anyone recommend a decent boiler with = a tough enough pump!?