Why gas, instead of ducted heat pump so you get cooling as well? Electric is driven from hydro, rather than burning fossil fuels, that could be a consideration. 

Already use gas for cooking and hot water, so thought of using the same for central heating as well. But, will look into the electric option as well, any suggestions?

do you have mains gas or bottles?

mains gas. as of now have one heat pump in living room, but bedrooms are fitted with heat panels by the previous owner.

In Wellington we use heating probably ten months of the year, sometimes a little, sometimes a lot, so I do agree heating is more important. We do appreciate cooling though, especially in our very sunny kitchen, but also at night on the really hot days to take the edge off the bedroom area. I'd really like to get ducted cooling for the bedrooms at some point.

Try this thread for a recommendation of a central heat pump installer. HRV are apparently quite cost competitive compared with many heat pump installers, maybe because they're so used to doing ducting.

Thanks :) will check it out

Based on my experience with getting a ducted heat pump installed, I would be very wary about focusing on a 'good deal' first and foremost.

Rather, whether you go with gas or heat pump, I suggest focus on the experience and workmanship of the various companies in doing similar installs, and personal recommendations from others who have used them.

It's too important a job to take a risk of getting a second-rate install, which you may need to either spend more money on to get put right or live with an under-performing system.

I have friends in Wellington who had a gas central heating system installed, though I'm not sure of the brand (it uses radiators). They love it, but I understand it's (no surprises here) pretty expensive to run. I can ask them who they used and what they thought of the company - let me know if you want me to follow this up.

timmmay:

 

Why gas, instead of ducted heat pump so you get cooling as well? Electric is driven from hydro, rather than burning fossil fuels, that could be a consideration. 

 

A bit off topic, but I agree electric would be a more future-proofed option. NZ is eventually going to run out of gas, and combined with higher carbon pricing, this will increase the price of gas in the medium to long term I imagine. 

I bought a house with gas burners in the kitchen, a gas fireplace, and gas hot water. My plan is to get rid of it all when I can afford to and as they get older (and I would be looking at a ducted heat pump for heating). 

jonathan18:

 

Based on my experience with getting a ducted heat pump installed, I would be very wary about focusing on a 'good deal' first and foremost.

 

Rather, whether you go with gas or heat pump, I suggest focus on the experience and workmanship of the various companies in doing similar installs, and personal recommendations from others who have used them.

 

It's too important a job to take a risk of getting a second-rate install, which you may need to either spend more money on to get put right or live with an under-performing system.

 

I have friends in Wellington who had a gas central heating system installed, though I'm not sure of the brand (it uses radiators). They love it, but I understand it's (no surprises here) pretty expensive to run. I can ask them who they used and what they thought of the company - let me know if you want me to follow this up.

 

Yes please, it would be helpful. Much appreciated.

howdystranger:

 

A bit off topic, but I agree electric would be a more future-proofed option. NZ is eventually going to run out of gas, and combined with higher carbon pricing, this will increase the price of gas in the medium to long term I imagine. 

 

By the time NZ runs out of gas, NZ will be Raro-tropical-paradise :) but price yes in short term.

In theory if prices goes up on fossil fuels - demand drops, on the other hand demand for electricity goes high - prices will follow too.

I'm wary of central heating systems because many good systems are more expensive because of factors that people don't really think about like the house shape.

All continuous central heating is almost always more expensive than intermittent, localised heating (heating when you need it, where you need it in the house). That's why we won't centrally heat our house which is a long rectangle. Instead we use heating sources in three locations which can run continuously to heat each area:
- heat pump for main living rooms and entrance
- heat pump for other living area and bathroom
- dehumidifier/heater for hallway, 4 bedrooms and bathroom

When we installed gas heating in a previous house, the install cost of gas heaters and radiators was too much compared with electric heaters. Yes, you can save a lot of money using them but the difference in installation cost meant a long payback and marginal net benefit. The installed costs for each gas heater was 5-9x more than electric. The gas appliances still required an electrical connection so there was no saving there. Their main advantage was that they could pump out 2-6 times as much heat but that is not so important if rooms are already warmed. When we do heat the entire house we aim to heat in the range 16-20C and only get higher temperatures when we need them. As an aside, we had a boarder who would set the thermostat to 34C in mid-winter and walk around with bare feet and one layer of clothing.

We separated out the costs of generating the heat and the costs of transferring the heat. Then looked at the transfer loses - they all lose too much heat for our liking. The same applies to central heating systems that transfer heat. They can be expensive because losses are quite significant due to the comparatively large surface area of ducting. This gets worse if you have long runs of ducting, if the ducting is in the roof space, and increases with the temperature differential (inside vs outside the duct). Also transferring a lot of heat using air requires a high temperature differential at the source room.

Piping a liquid is usually more efficient because you can transfer much more energy in a shorter time which simplifies temperature control at each outlet. But again, the heat losses can be just as significant at the higher temperatures of the fluids.

Really, heat transfer it is most worthwhile using if you have a fuel source much cheaper than gas such as free firewood.

Traditionally , a lot of people don't keep their entire house warm, they only heat areas which they are using, otherwise you can be wasting a lot of energy.  Gas can be a cheap way to heat the house, but that may not always be the case. In my house, we use heating perhaps 4-6 months of the year. Intermittent cooling for about 4 months. IMO cooling is becoming almost just as important as heating, as temperatures increase and summers get hotter. But it depends on where you live, as well as how much passive heating your house gets from the sun. If it is a new house, it should have been designed to get the free solar gains from the sun. But many standard off the plan houses aren't designed for this, as there isn't currently any requirement to do so. But it can save the home owner a lot of money in heating costs.

Hammerer:

 

As an aside, we had a boarder who would set the thermostat to 34C in mid-winter and walk around with bare feet and one layer of clothing.

 

We set the heat pumps so we can wear a single layer in winter. We only needed it 21 - 22 for that. It's much nicer that way, but each to their own. 34 is crazy.

Hammerer:

 

I'm wary of central heating systems because many good systems are more expensive because of factors that people don't really think about like the house shape.

 

All continuous central heating is almost always more expensive than intermittent, localised heating (heating when you need it, where you need it in the house). That's why we won't centrally heat our house which is a long rectangle. Instead we use heating sources in three locations which can run continuously to heat each area...

Some things are about more than the financials; some of the factors you're not necessarily considering (or not valuing to the same degree as we do) are non-financial, ie convenience and comfort.

TBH, for most households buying a number of fan heaters for $20 and sticking one in each room and using those when needed is probably the cheapest option even in the medium term, but few are going to do that because it'll be a real hassle to do so and not particularly pleasant. Ducted systems are at the other end in terms of convenience - a single point of control for heating (or cooling, if a heat pump) a whole house. [One can also elect to heat parts of the house (using zones, or even shutting down individual rooms by closing vents).]

When we moved into our current house - a 1920s villa, much of it with 3m stud - I realised I was totally over living in a cold house; I'd been brought up in a 1900s villa, where the kitchen could be 5 degrees in winter, and the only way of heating it semi-effectively was to heat only the room being used at the time. I also got sick of the hassle of carting firewood and starting a fire, and the delays in waiting for the fire to heat the house. I wanted it that we could have the whole house liveable and pleasant to be in with minimum fuss - that's what a ducted system has allowed.

Yep, it wasn't cheap to install (but it's absolutely affordable to run if one is sensible - we use our hour of free power to heat between 6 and 7, set it at an appropriate temperature of about 18-19, and don't run it 24/7.), but was totally worth it in regards to being hassle-free and creating a comfortable environment. That's priceless in our books.