heating/cooling

one of the major decisions when designing and building a house is the heating/cooling issue.
our main prerequisites:

energy efficient
economical exploitation
green
modular and easily programmable
integral (one solution for underfloor heating, radiators and fan coils)

this list is not a easy one, so after some research it became clear that an air to water heat pump is a desirable option. We dismissed the geothermal heat pump because AirSourceHeatPump differs in three crucial respects:
• it doesn’t require digging and rolling out 100s of meters of tubing
• instead it works by taking heat out of the air
• it’s cheaper and easier to maitain compared to GSHP

ASHP systems are relatively new, but what they claim to do is so desirable that I see them as the next big thing. Air to Water HP is not a renewable power source, as it uses electricity, but because the way heat pumps work, it will use about a third of the electricity an electric immersion heater would use. That means that our proper insulated 200 m2 house will be heated with just 3 KW/h. Wermutstropfen is that you need:
1. Really good insulation, because the heat pump delivers relatively low temperature heat - water with 45-55 degrees Celsius which is unsuitable if your house wastes a lot of energy trough the windows and poorly insulated walls. In our case this should not be a problem.
2. The efficiency (COP & EER) tends to decrease when it gets really cold, like below -10 degrees Celsius. In that cases in is not unwise to install an alternative backup heater. So for the coldest days we intend to use the fireplace as a backup.

Air to Water heat pump systems:

1. Daikin Altherma
2. Hitachi Aqua Free
3. waiting Mitsubishi Aircon and Toshiba to produce something similar.