As winter sets in, across the country New Zealanders start cranking up the heaters and electric blankets as we battle against the chill to try and stay warm. But while we all want to stay cosy, it often comes with a big price tag as power bills tick up, hitting us hard in the pocket. 

Although a higher power bill might seem unavoidable for the winter months, there are some great preventative steps that can be taken to make sure your home is heated as efficiently as possible. One of the biggest reasons for inefficient heating? Having dampness in your home. By reducing damp, your home is drier and can be heated more efficiently than before. Read on to learn more about dampness, where it comes from, how it affects heating and ways you can prevent it from occurring in your home. 

How Do You Know if Your Home is Damp? 

Although dampness can sometimes be hard to spot, there are tell-tale signs that your home may have a moisture problem. By learning how to spot excess moisture and damp, you’ll be better able to find the right solution for your home’s particular issue.

Dealing with dampness indoors can be a real pain and a time-consuming task. A home with a moisture problem can give off a musty smell. While this may be noticed throughout the whole house, dampness often hides in places such as wardrobes, so if you’ve ever opened a wardrobe to find it smells musty, this could be a sign your home has excess moisture.

Another sign of dampness is that areas of your home will be cold and wet to the touch. Walls, ceilings and carpets shouldn’t feel wet, so if you’re finding this then your home may have a dampness issue. If you notice that your furnishings, such as couches and beds are starting to feel damp, or even show signs of mould and mildew, it’s probably a sign of a wider problem. Even if you don’t notice damp spots in the main living areas, it could be hidden away in wardrobes and cupboards, or behind furniture, so be sure to thoroughly check.

Mould on wall indoors

As well as touch and smell, dampness is also something you can see. This could appear in the form of windows crying with condensation, indoor mould and mildew growing on walls and ceilings, or darker, wet patches or streaks on walls. Wallpaper doesn’t like overly wet environments, so if you notice it starting to peel from the walls, this could be caused by damp.

There’s also a number of ways to spot damp on the outside of your home. If you notice rotting wood on your home’s exterior, this could mean that it’s been weakened by dampness. If you see that water has trouble draining from your property — particularly from under the house — be vigilant in ensuring that it isn’t causing bigger problems than a muddy puddle. Check underneath your house to see whether mould may be growing — a tell tale sign of excess moisture. 

If you’re unsure if your home has a problem with dampness, or not certain where the problem might be the worst, you can use a low-cost hygrometer to test the indoor temperature and the relative humidity. For reference, your home should be at least 18°C and below 65% relative humidity [1]. To get the most comprehensive readings, use the hygrometer in different rooms over a few days, and make particular note of the readings in winter. Doing this will help you find the spaces of your home that have the highest humidity.

Where Does Dampness Come From? 

Laundry drying indoors

While we now know you should have below 65% relative humidity[1] in your home, it’s only once you know how to identify where all that moisture comes from that you’ll have any chance of combating it.

Moisture in the home is inevitable, it’s produced not only by the many day-to-day tasks we carry out but also by simply breathing. Rooms that are big moisture producers are spaces such as the laundry, bathroom and kitchen — areas that see a lot of water being used. Most households produce approximately eight litres of water every day from all of these activities!

Dampness outside can be a problem for a house when water is trapped with no escape route. If pipes are broken or leaky it can lead to water pooling close to your home. This could also happen if your property doesn’t have sufficient drainage, or if drains are blocked by plants and soil.

Why Does Removing Dampness Make Heating More Efficient? 

You may be wondering why reducing damp makes heating more efficient. The answer is simple: It takes far more energy to heat humid air than it does to heat dry air because you’re heating more water. 

It’s a bit like taking a soaking wet jumper and putting it on the line to dry. It’s going to take far longer for the jumper to dry than if it had been through a spin cycle to remove as much moisture as possible beforehand. The more moisture in the air of your home, the longer your home will take to heat, and the more power it may use to do so.

What Can You Do to Reduce Damp in Your Home? 

There are many things you can do to reduce damp and many of them require very little effort[2]. 

Extractor fans 

Remember to use extractor fans when using the bathroom or kitchen (or a range hood). If you don’t have an extractor, consider installing one. They’re relatively low cost and will not only help with moisture but odours too. When possible, cover pots and pans when cooking and avoid drying washing indoors — save it for the outdoor line instead. If you’re using a clothes dryer, try having it vented through the wall or out a window so that it’s not filling your home with more moisture. 


Dehumidifiers are commonly used to remove moisture from the air and they’re very useful. However, they’re not a permanent solution to the problem, they’re simply reducing the symptoms. Dehumidifiers are useful when it’s raining and moisture levels are increased, though they should be run alongside a heater as warm air makes it easier for a dehumidifier to remove the moisture[3].

Install a home ventilation system 

Properly ventilating your home is a fantastic way of reducing damp and a ventilation system is a simple way to ensure this is done constantly. A home ventilation system takes the air from your roof space, pushes it through a filter and distributes it around your home via ducts. With the movement caused by the drier air entering your home, the old, staler air is forced out, carrying excess moisture with it. 

HRV Ventilation Duct

It’s important to note that not all homes are suitable for ventilation. In some cases, ventilation can’t be installed because:

  • There’s no roof cavity or it isn’t accessible
  • There are holes in the roof or ceiling
  • There’s excess moisture in the roof cavity or sub-floor
  • Extraction fans or rangehoods are vented into the roof cavity

If you aren’t sure if your home meets the above criteria, but are still interested in a home ventilation system, our HRV team can come visit you for a free home assessment. They’ll work out if your home is suitable and if it isn’t, offer some advice for helping manage damp and/or mould. 

A ventilation system, like those available from HRV, can help create a comfortable atmosphere and most importantly, a drier home. And, with your home drier, you’ll find that it’s far more efficient to heat. HRV home ventilation systems are all installed by qualified installers, are backed by a five year system warranty and can have a long term impact on your family’s comfort.

Heat Pumps – An Efficient Heating Solutions 

When choosing a heating solution for your home you want to make sure the method you choose suits the space you’re heating and will be efficient in the long run. With the new Healthy Homes Standards set out by the Government, there are now guidelines on which systems are best for homes and which are best avoided.

A heat pump is a fantastic system that will work quietly to heat your home in an energy efficient manner. Heat pumps like those in HRV’s Panasonic range, are able to operate even when the temperature outside is as low as -15°C, making them efficient heaters NZ-wide — even in the coldest regions. They easily heat your home to the World Health Organization recommended minimum of 18°C, and require no forward planning, such as fuel or firewood purchase. Heat pump costs vary but they make efficient long-term solutions, when installed and used correctly, and they’re also easy to install in both new and existing builds. 

HRV Heat Pump On Wall

If you’re ready to learn more about ventilation and heating options for your home, the HRV team are ready to help. Book in for a free home assessment with our helpful and knowledgeable professionals today.