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Is hydronic underfloor heating right for me?
It really is very simple and cost-effective. However, there are a few things to consider and it is best to talk to warmth.nz to find out more. Anyone building a new house will get a benefit from hydronic underfloor heating compared to just installing wall-mounted heat pumps. How to get maximum benefit requires consideration of insulation, house orientation to north etc. On this basis, some houses will be much more efficient to run due to thermal gain and design factors. Hydronic underfloor heating is superior to all other forms of heating.

How do I get the best results?
This varies from house to house and personal comfort levels. We can advise on who to talk to regarding insulation, building materials, thermal gain and losses. We can also provide information on the best size of heat pump for in-slab heating and hot water heating. Hot water heat pumps are as efficient as conventional high wall heat pumps. However, the whole house is heated and there are no draughts.

How does it work?
Underfloor heating has been used for centuries. The Romans used it for home heating about over 2000 years ago. The heat pump heats water and circulates it through a network of pipes laid in the floor. The house is divided into a series of zones or regions and controlled by a manifold placed inside the house. By circulating the water on a frequent basis the slab is evenly heated. Overall control is set by a thermostat placed in a neutral heat zone in the house. This means it will not shut down due to high heat from the sunny side of the house and keep on running due to being on the cold side of the house. The temperature can be programmed to go down to a predetermined temperature before the heat pump starts heating the slab up again. Hydronic heating with water pipes in the slab is simply the best way of heating a home.

Am I better to have a higher capacity heat pump for underfloor heating?
Hot water heat pumps have similar efficiencies. A larger unit will cost more to purchase, run for a shorter period of time, and cost the same to run overall.

Do air-to-water pumps work on very cold days?
Yes, but not quite as efficiently as on warmer days. They will still be more efficient than other forms of home heating. Note – a slab can store a lot of energy, so a house will not go really cold in winter – whatever the weather

Can I alter the temperature room by room?
You can turn rooms off but generally leaving them on means the house is evenly heated with minimal losses. The flow through every run of pipe can be adjusted to lower the relative temperature – hence it is easy to reduce bedroom temperature for example.

How much more than air-to-air heating does this system cost?
A conventional heat pump cannot heat the floor, so the comparisons are not really relevant.

When the temperature of the concrete slab changes, will it affect my (wooden) floor?
No. If the slab is prepared properly and the wood applied correctly, the heat in the slab won’t affect flooring. Some carpet underlays may act as a thermal barrier, and you should check this with your carpet supplier. The maximum floor surface temperature is 25 degree Celsius.

Is it expensive to run?
The maintain the same temperature, the system is only replacing the heat the house losing. The less heat the house loss, the less the system needs to run. The system is controlled by a wireless thermostat. You can choose the temperature or running cost. The warmer the house, the more it costs to run.

Can I use an air-to-water heat pump for cooling like an air-to-air heat pump?
No. However, a well-designed house with adequate eves will be cool during summer times. We recommend that you consider ventilation to keep air fresh in your home.