Healthy Homes Confusion - Re heating tool

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1043 posts

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#3102582 11-Jul-2023 10:39

openmedia:

Compare their calculator with a typical heat pump calculator like

https://www.mitsubishi-electric.co.nz/heatpump/how-to-choose-the-right-size-heat-pump.aspx

that calc is so stripped down its complete BS. its a marketing tool not a real calc.

it doesn't even factor in window size, which is the single biggest factor in insulation performance.

MightyApe

You will find anything you want at MightyApe (affiliate link).

SirHumphreyAppleby

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Uber Geek

#3102586 11-Jul-2023 10:46

tweake:

small point, i would call that a 70's. @handle9 was saying a little while ago wall insulation was required in the late 70's. i have fully insulated 80's house that has 70's windows ceilings etc, ie made from left overs. insul fluff ceiling and no wall insulation was pretty typical for late 70's from what i've seen from crawling around in the stuff.

The house was built in 1986 and I know for a fact there is no insulation in the walls. I've had them open in several place and run cables through most of the house. There is only building paper between the Gib and exterior wall cavity. Whether a brick cavity wall met the requirements without additional insulation, I cannot say.

We maintain 15.5-16C throughout much of the house using the aforementioned 1.8kW. That's a more than comfortable overnight temperature and easily maintained. We're never starting from the minimum required temperature, where we clearly would need more power, but that's an absurd point to start from IMO.

esawers

515 posts

Ultimate Geek

#3102597 11-Jul-2023 11:27

Noone except maybe the tenants are happy with the Healthy Homes calculator, either way if you want to rent your house out you will need to provide a fixed heating source such as a heatpump or fire (not a portable heater). If an existing heatpump isn't powerful enough then you can top up with another fixed heating source.. yes it is nonsense for alot of houses (our own home would never meet healthy homes standards being open plan, yet we are very comfortable) but its a start to providing warm dry homes for tenants.

esawers

515 posts

Ultimate Geek

#3102601 11-Jul-2023 11:31

Interestingly most new builds don't meet Healthy Homes standards either, if you are building for a rental property make sure you specify all of the Healthy Homes conditions or you will be looking at heatpump and extractor fan upgrades (and possibly moisture barrier) before anyone even moves in.

tweake

1043 posts

Uber Geek

#3102604 11-Jul-2023 11:40

SirHumphreyAppleby:

The house was built in 1986 and I know for a fact there is no insulation in the walls. I've had them open in several place and run cables through most of the house. There is only building paper between the Gib and exterior wall cavity. Whether a brick cavity wall met the requirements without additional insulation, I cannot say.

We maintain 15.5-16C throughout much of the house using the aforementioned 1.8kW. That's a more than comfortable overnight temperature and easily maintained. We're never starting from the minimum required temperature, where we clearly would need more power, but that's an absurd point to start from IMO.

brown aluminum windows?

i'm not sure on what happened back in the day, i've run cables on places like that. some didn't even have building paper. i don't know if it was a loophole or just short cuts taken and slack council inspection.

not sure what you mean by "We're never starting from the minimum required temperature, where we clearly would need more power". your only heating up to 16c which is below minimums required and well below recommended temp. your not starting from minimums because your not even up to minimums in the first place.

btw we are talking lounge here, not bedrooms which can be cooler.

tweake

1043 posts

Uber Geek

#3102605 11-Jul-2023 11:45

esawers:

Interestingly most new builds don't meet Healthy Homes standards either, if you are building for a rental property make sure you specify all of the Healthy Homes conditions or you will be looking at heatpump and extractor fan upgrades (and possibly moisture barrier) before anyone even moves in.

its appalling. its far cheaper and easier to install all that stuff as part of the build.

i would also add ventilation system. if you have a ventilation system then you no longer need opening windows so there can be cost cutting tho i would leave some opening windows as fire escape.

richms

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#3102607 11-Jul-2023 11:56

Their calculations are BS, a friend had the bureaucrats come around and measure their rental up because the managers they rented from insisted on it if they were to keep managing it,

Anyway, the place was always warm, had an aircon in the living space that dealt with it well and the beancounters decided they had to measure an adjacent kitchen area because it had an opening to it.

Result was that the aircon was well undersized for their beancounting, and the owners had to slap an ugly wall mounted heater on the wall to bring it up to enough kW. They knew that it was pointless so did the cheapest job possible and now they have to have their TV unit way off the wall because of a heater attached to the wall.

Richard rich.ms

SirHumphreyAppleby

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Uber Geek

#3102609 11-Jul-2023 11:58

tweake:

brown aluminum windows?

Brown, anodized aluminium, as was common at the time. We actually had one of the windows out a year or so back and they are apparently thicker than was typically used at the time, but still single glazing. This may have met the technical requirements at the time.

not sure what you mean by "We're never starting from the minimum required temperature, where we clearly would need more power". your only heating up to 16c which is below minimums required and well below recommended temp. your not starting from minimums because your not even up to minimums in the first place

I'm referring not starting from 1C or whatever the applicable minimum outdoor temperature is. The house is typically 19-22C during the day, and we maintain that during active hours, after which we let it fall to 15.5C, because that is what we deem to be an acceptable overnight temperature. The temperature is dropped because it is more economical to maintain that temperature, not due to a technical inability to do so... the heater only cycles from around 3-4am and has a duty cycle of well below 50%.

cddt

657 posts

Ultimate Geek

#3102611 11-Jul-2023 12:00

richms:

now they have to have their TV unit way off the wall because of a heater attached to the wall.

Some of those early flat screen TVs (plasma?) doubled as panel heaters too!

tweake

1043 posts

Uber Geek

#3102626 11-Jul-2023 12:54

SirHumphreyAppleby:

Brown, anodized aluminium, as was common at the time. We actually had one of the windows out a year or so back and they are apparently thicker than was typically used at the time, but still single glazing. This may have met the technical requirements at the time.

I'm referring not starting from 1C or whatever the applicable minimum outdoor temperature is. The house is typically 19-22C during the day, and we maintain that during active hours, after which we let it fall to 15.5C, because that is what we deem to be an acceptable overnight temperature. The temperature is dropped because it is more economical to maintain that temperature, not due to a technical inability to do so... the heater only cycles from around 3-4am and has a duty cycle of well below 50%.

certainly sounds like typical 80's, not sure why no insulation.

the 1c outdoor is used to work out what size heater is required, houses typically don't fall to outdoor temps.

dropping temps overnight is typical, much the same myself. the houses are to low quality to heat fully tho a 16c set back is not to bad considering, many do much worse.

however i still highly doubt your heating the house above 18c with a 1.8kw heater even in auckland/northland climate. either insulation is better than expected or another heat source like lots of sun which has its own trade offs.

Handle9

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#3102752 11-Jul-2023 14:55

Bung: The Government knows the calculator is a lemon and made changes for homes built after 2008. The method used in the calculations should be fixed instead. Why should a fully retrofitted building not be treated the same?

The tool is fine. You can input your actual insulation values if you know them.

If you bother to read the notes it states that it’s conservative and will likely oversize the heating required, which means that it meets the intent of the legislation.

You’re always free to use the calculation method as an alternative. You can also engage a professional to do this for you. What you can’t do is use anectdotia as “proof” of compliance.

networkn

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#3102755 11-Jul-2023 15:07

Handle9:

It's going to cost OP some money to become a landlord. That is the issue.

Not necessarily, but like any business, you don't want to spend more than is efficient to get the job done. No chance the average lounge would need 7kW if it's insulated to even a basic standard. Our 7kw heatpump in the lounge covers the lounge, living area, dining area and kitchen and can heat that very effectively in a very short period of time. Admittedly we aren't living in a 40's house, but if the insulation on a 40's house is efficient...

He has lived there, and has some real-world experience with the particular home.

concordnz

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#3102763 11-Jul-2023 15:22

Beauracrats don't care about real world experience.
(or what's been done to improve the insulation)

It could easily be a shitty tenant 2-3 tenants down the line that decides they want (all) their rent payments back,

When they leave - they will take you to the Tenancy Tribunal & THE Tenancy Tribunal will simply look at the calculator (they will wilfully choose to ignore the qualifiers on the website).
& they will claim your property is not "up to standard" and you owe the bad tenant a refund of their rent due to you allegedly providing a substandard dwelling.

Put the 'oversized' heat pump in as per the calculator...... And the tenants simply have to put up with it short cycling all the time - if they complain, simply point out you had to put in that oversize unit due to the Standard/Beauracrats...

This will save you way more stress and heartache, than going through the Tenancy Tribunal BS in the future.

Handle9

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#3102764 11-Jul-2023 15:25

networkn:

Handle9:

It's going to cost OP some money to become a landlord. That is the issue.

Not necessarily, but like any business, you don't want to spend more than is efficient to get the job done. No chance the average lounge would need 7kW if it's insulated to even a basic standard. Our 7kw heatpump in the lounge covers the lounge, living area, dining area and kitchen and can heat that very effectively in a very short period of time. Admittedly we aren't living in a 40's house, but if the insulation on a 40's house is efficient...

He has lived there, and has some real-world experience with the particular home.

OPs anecdotes aren’t heat load calculations. Building owners are extremely unreliable narrators, and OP has already stated that they need additional heating on cold days.

The calculations are in the legislation as are the design conditions. It’s really not difficult although the calculations are reasonably complex.

Edit: typos

SirHumphreyAppleby

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#3102765 11-Jul-2023 15:25

Handle9:

If you bother to read the notes it states that it’s conservative and will likely oversize the heating required, which means that it meets the intent of the legislation.

My understanding is the calculator implements the calculations set out in Schedule 2 of the Residential Tenancies (Healthy Homes Standards) Regulations 2019. The intent, which the regulation states can be met if a suitably qualified professional says so, does not align with the requirements to establish compliance by other means (i.e. the calculator).

The risk of non-compliance is a pro-tenant Tenancy Tribunal. I'd rather spend a few hundred dollars more on a larger AC unit to be on the safe side.

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