Topic: Heating new homes in Christchurch

Heating new homes in Christchurch 

With all the new houses (and commercial properties) that will be built in Christchurch - now is the time to install water pipes in every new floor that is laid.

This water can be heated with wood, diesel, electricity, gas, pellets...or the most convenient/efficient system at present - a hot water heat pump......

so that every room in the house is warm at reasonable cost.

We could supply and install these pipes (to NZ standards with a 50 year plus life span) in an average 3 bed new home for $2000 plus GST.

Anybody have an comments? Anyone have any other ideas?

JK

Re: Heating new homes in Christchurch 

Sounds like a good idea and well worth considering but another idea is to build a passive house or close to passive house standards so that very little additional active heating is required

Re: Heating new homes in Christchurch 

I'll second the idea of building ALL new buildings to near Passive standard. It's such an amazing opportunity to do it once, do it right.

Re: Heating new homes in Christchurch 

The June/July issue of The Shed has some good articles on sustainable homes for Christchurch. But guess what?

"The package has required a push, says Nick Collins, general manager of Beacon Pathway, because insurance companies want to pay only to restore what was there--for example, remaking a 1920's house with no insulation, brick veneers that have fallen off, concrete tile roofing where a flexible steel room would be more resilient."

"How do you put a value on warmth and comfort? Why don't we value good quality housing? he says.

I gather that the government does not require rebuilding to be up to code?? Is this for real? When I read stuff like this I wonder whether our NZ housing has made our minds as sick as our bodies? I am no longer optimistic. Leo

Re: Heating new homes in Christchurch 

Guys what are you dreaming?
The building mafia has already cut the cake.
Passive house know how is available for many years now and the Government and bulding industry has ignored it. Why would they change from backwards to progressive over night??

Re: Heating new homes in Christchurch 

ZZZZZ ..huh...snort
Gee I was dreaming.
Ahh well it was a nice dream.
Thanks GW for the reality check!

Re: Heating new homes in Christchurch 

JK

What would be the additional cost if the pad is poured without pipes, but then insulated, and piping installed in a screed layer above the insulation layer? I presume your pipe and install costs wouldn't be any different?

Seeker

Re: Heating new homes in Christchurch 

AFAIK even with a Passive House you need some heating -
The important fact is that pipes in the slab can be used or not - even with a completely standard NZ build it would appear the energy cost for a three bed house is about $300 a month - with all the hot water and every room warm. How much is it worth spending to significantly reduce this?

Seeker - we fit the pipes by stapling directly onto polystyrene insulation - they are out the way (almost impossible to damage) and the standard 100mm slab is great for retaining energy when a heat pump is used (so it can be run in the day for greater efficiency).

Fitting pipes into a screed is the European way, better for quick response when using gas or diesel.
The cost would be identical (as long as there is polystyrene) - but I think the slab cost would be higher.

It's possible that all new slabs will have to be "rib raft", great for pipes.

The thing is that for $2000 plus GST (1% of build price?) all options are open - from a house to minimal standards to the very best.

As we now know a house only built to code (with aluminium framed windows!) is not expensive to heat........as long as there are pipes in the slab.

JK

Re: Heating new homes in Christchurch 

It is important to insulate around the perimeter also. We are able to offer a FULLY insulated raft slab www.maxr.co.nz

Re: Heating new homes in Christchurch 

What on earth is wrong around here??
Perimeter insulation should be standard for many years now...

Re: Heating new homes in Christchurch 

We just did this with ICF. Effectively 100mm poly at the edges (50mm poly, 150mm concrete then 50mm poly again), with another 50mm poly sitting underneath. This cost $2645, for a 220m@ slab.

Re: Heating new homes in Christchurch 

I have a question. Wont you require areas of uninsulated slab with no poly? Otherwise wont the weight of the house simply crush it to nothing? I have seen the poly blocks of rib raft floors and they have big gaps between the poly. But I should imagine someone doing this themselves will just cover the entire area.

Re: Heating new homes in Christchurch 

@Still Not Telling. In our case yes, we do have a couple of key areas under supporting walls where the slab is thickened and where (I assume) we'll have no poly under. The poly goes in today, I'll take a look. I'm sure someone will correct me if I'm wrong but AFAIK in terms of overall thermal performance insulating the perimeter is actually much more important than underneath?

Re: Heating new homes in Christchurch 

Hi all, we are lucky enough to be in a new home with underfloor heating and its using less than 14 units (kw/h) a day to heat.
The last 7 days units used were....
13.3,12.7,12.0,12.9,12.2,13.3
Around about 5 hours a day of heating to use that number of units.

If anyone would like unbiased comments please ask and I'll do my best to answer.

Re: Heating new homes in Christchurch 

Yes, I'd like to know how your floor is insulated and how the temperature is controlled

Re: Heating new homes in Christchurch 

40mm Poly up to the footing around the edges, with the pipework stapled to that then the concrete slab poured over. Only a couple of hours before you start feeling when heat has been added not days!!
I have retrofitted the standard controller with a web based unit so I can turn the heat on twice a day and then heat to a set temperature.
(See image attached, the temps displayed around the house are for in the slab )
I installed DS18B20 1-wire sensors in the slab for this reason, one thing I found is you need to ensure they are not too close to the pipework or they heat up to quick and the data is not really useful, I logged the three I put in and selected the best one to use for the thermostat sensing.

Re: Heating new homes in Christchurch 

Wrote this last night - forgot to post!

We recommend poly underneath as it is straightforward to staple the pipes to - 40mm would appear to be enough (any energy that goes into the ground doesn't disappear unless you have running water).
Edge insulation is probably more important - but trying to get a builder to actually install it is much more difficult.
To overcome the problem we install the outer pipes some distance from the edge as a pragmatic solution.

A customer is reporting monthly energy bills under $300, with a house that's too hot for me - and six people (three bedrooms). This includes all the hot water.

JK

Re: Heating new homes in Christchurch 

Wrote this last night - forgot to post!

We recommend poly underneath as it is straightforward to staple the pipes to - 40mm would appear to be enough (any energy that goes into the ground doesn't disappear unless you have running water).
Edge insulation is probably more important - but trying to get a builder to actually install it is much more difficult.
To overcome the problem we install the outer pipes some distance from the edge as a pragmatic solution.

A customer is reporting monthly energy bills under $300, with a house that's too hot for me - and six people (three bedrooms). This includes all the hot water.

JK