I'm considering fitting one of these. Perhaps this one:
R.
Looking at the prices; £400+ for the unit then all the ducting and face plates and power, it starts adding up.
Do you need the heat exchanger? The system we have in the extension is basically one half of the above unit - extract only, and no 'air in' so relies on 'trickle ventilation (fresh, not warmed air) It seems to work well and is very quiet (I can only just hear it working if I listen carefully in the bathroom) I'm planning in fitting another in the 'old' house.
The VMC units (Ventilation Mechanique Controlee ??) are around 100euro in France. I looked at the heat exchange version but ruled it way out ofmy budget immediately.
Regards John
Yes, I do have an hayfever problem, and here in cold old Cumbria I live in the middle of grass land! I could move to Brighton, I know.
My house is fully insulated and well sealed, so there may be some benefits for us. One of the problems we have in equalising the temperature though the building, only one side gets any solar gain, so this would help that too if I make the input air come mainly into the cold end.
R.
Yes, I live in Cumbria. What comes thought the trickle vents is an icy blast - in July.
As it's a DIY jobby for me I thought I might make the ducts and fittings. I can't see why 25mm celotex and 6mm ply can't be used to make square-section insulated ducting, it's just a matter of the right cross sectional area and tight joints.
The power is an issue though. Especially if it doesn't deliver the stated thermal transfer efficiency, or it falls off rapidly as the filters clog.
R. =20
Not that one but we have had a similar whole house ventilator for the last 20 years and it has been very useful. The heat recovery side (in all these units) is a bit minimal as air has low mass - so don't expect warm air to come out of the trickle vents, it might be a few degrees above ambient but not much else. Motor life is about 5-10 years before the bearings fail. We built it in to a new build house - retrofitting may not be as easy as the manufacturers claim.
It certainly makes the house environment fresher and the bathrooms dry quite quickly. If unit has a cooker extraction hood option I would not fit that - the extractor pipe will get coated in cooking oil and pick up dust and fluff. Simply use a normal ceiling extractor vent somewhere convenient in the kitchen area. We mounted our motor box on a 2 inch thick slab of rubberised horsehair on a board in the attic and it is for all practical purposes silent.
There are no perceptible cold draught unless you sit almost immediately under an inlet vent in a corner in which case you might just about detect the cool air descending.
Definitely something I would fit again.
Airtight and woodburning stove don't go well together.
AJH
The average British house is very air leaky. The house has to be pretty air-tight to justify a Heat Recovery and Vent system, otherwise you are venting it twice.
Assuming your house is very well insulated and pretty well air tight. If fitting one of these system then have a copper heater coil in the ducting supplying heating to house. A combi can provide hot water to the coil. This is all it may need depending on:
Then no expensive rad or UFH systems. A high flow combi can heat the copper coil, saving space on cylinders and cost giving a simple ferrous free system, so no sludge build ups. Using the combi makes the whole system cost effective 0- fresh air, heat recovery and heating. Copper duct coils can be installed at various points in the house if the insulation value is not that great - one for downstairs, one for up. It also provides zoning, so upstairs can be off, while downstairs is on and vice-versa. The makers usually provide these coils or will direct you to a supplier.
Yes I saw your other post after I replied. I was not aware of any room sealed wood stoves. I think building regs require a vent on any solid fueled stove over over 5kW, I wonder if there is an exception for room sealed.
AJH
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