#(remember ventilation means removing stale, humid air)
As far as I have been able to find out, there is only one New Zealand company that manufactures a true HRV system and it is not HRV (hrv.co.nz). It is Cleanaire or AVON Electric based in Christchurch. (http://www.cleanaire.co.nz/)
There is great confusion in this country about what constitutes a true HRV. I'm sure many of you already know this but thought an explanation would be good to know for some.
A true HRV system: -
1.) Brings in FRESH outside air
2.) Filters out dust.
3.) Passes the air through a heat exchanger which warms it (see 4.) so cold air is not blown into the house. This saves energy.
4.) The warm, stale, humid air in the house is drawn out and passes through the heat exchanger so its heat is not expelled from the house, just the stale, humid air.
5.) Any excess condensation is drained from the main unit.
6.) The whole main unit and all ducting is insulated.
7.) The heat exchanger is metal, not one of those absurd cardboard ones DVS uses. Think about it and heat transfer????
8.) Two separate, large, quiet fans - one for intake and one for expelling.
9.) In vents in lounge/dining bedrooms with warmed fresh air. The vents are by the windows so full cross ventilation happens not like "hrv.co.nz" whose vent are by the door??? Come on basic ventilation. Again a joke.
10.) Out vents in kitchen, laundry and bath/shower room so the moisture is removed BUT not the heat and again cross ventilation happens.
See animated diagram:
http://www.cleanaire.co.nz/why_a_cleanaire/What+does+a+HRV+do.html
Works best with a Heat Pump ( heat in winter, cool in summer) and ceiling, wall and floor insulation in the house.
Note: Yes even the concrete slab floors should be insulated as they act as a heat or cool store depending on season.
Works in reverse in the summer so the cooled aircon air cools the incoming fresh air, again saving energy.
A heat exchanger is just that a heat exchanger so it doesn't care from where the hot or cold is coming from.
Here in Hawke's Bay in the summer we shut the aircon off at night as we have cool evenings even after 30 degree plus day time temperatures. The HRV blows the cool, fresh evening outside air around the house so we sleep well.
Benefits:
1.) Constant fresh air brought into house 24/7 - we never open our windows which is good for security .
2.) No condensation what so ever. Even on the window aluminium frames - not double glazed yet - that's next!
3.) The heat from the kitchen, laundry, bath and shower is recovered and the moisture is removed. Saves money!
4.) Since moving into this house over 3 years ago I have not caught a cold or the flu (no shots by the way) and I'm over 65 and asthmatic!
5.) We are warm ( or cool) and dry. No mould in house even in bathroom
Maintenance:
1.) Wash heat exchanger with garden hose once a year.
2.) Wash air filters once or twice a year.
I trust this will help clear up some misconceptions.
Trusted
