Evaporative Cooling / Gas heating vs Refrigerated cooling

Shi · Nov 20, 2019 1:42 pm

Dear all,

My planned house is of single storey 29 squares with 4 bedrooms, 2 living areas and 1 open theatre . Total of 9 vents are present as per the standard design( 4 in bedrooms and 5 in living/theatre).

Below are the price list provide by the builder and I am bit confused with the options to go with.

Gas heating : regular one provided by the builder is Brivis 3 star, which cannot have zoning and upgrade to SP series - i.e. 4, 5 or 6 star would be required.

Zone upgrade option:
Zone Option 1 - Provide Brivis Zone Plus Heating System 2 zones to Single Storey $1,604.00
Includes 1No. Networker Controller (NC6) in lieu of standard programmable controller (included in upgrade to heating unit), 1No.temperature sensor, 2No. zone motors.
Zone Option 2 - Provide Brivis Zone Plus Heating System 3 zones to Single Storey $2,223.00
Includes 1No. Networker Controller (NC6) in lieu of standard programmable controller (included in upgrade to heating unit), 2No.temperature sensors, 3No. zone motors.
Zone Option 3 - Provide Brivis Zone Plus Heating System 4 zones to Single Storey $2,372.00
Includes 1No. Networker Controller (NC6) in lieu of standard programmable controller (included in upgrade to heating unit), 2No.temperature sensors, 3No. zone motors & 1No. 506 module

Unit options:
Unit Option 1 - Upgrade heating unit from a Brivis CC3 to SP4 (3 Star to 4 Star) unit, includes upgrade to networker controller in lieu of programmable $959.00
Unit Option 2 - Upgrade heating unit from a Brivis CC3 to SP5 (3 Star to 5 Star) unit, includes upgrade to networker controller in lieu of programmable $1,483.00
Unit Option 3 - Upgrade heating unit from a Brivis CC3 to SP6 (3 Star to 6 Star) unit, includes upgrade to networker controller in lieu of programmable $1,834.00

Evaporative cooling : Brivis Contour L66 unit to 8 points. $7,808.00

Refrigerated air conditioning: 14.80 kW (Nominal cooling capacity) single phase Brivis refrigerated air conditioning to 9 points including upgrade of the heating unit from the Brivis Compact Classic to 5 Star unit - $15,135 (so this includes Unit Option 2, which is builders $1,483.00)
I believe refrigerated air conditioning would be reverse cycle, so can be used for both cooling and heating. Yes, included 5 star gas heater would be another option for heating.

So the point is, if I upgrade to 5 star gas heater ( $1,483.00) and no zoning + Evaporative cooling ( $7,808.00), it would be $9291
With Refrigerated cooling (5 star gas heater and no zoning), it would be $15,135
Difference is - $5,844

Please note that most of the time around the year, only living and master bed would be used. Also, I will be using more of heating than cooling ( I can bear most of the summer heat, not the cold weather in the peak winter

). I am aware that refrigerative cooling is a closed system and for Evaporative cooling to work, there should be few windows opened.

My confusions are,

1) Is it worth upgrading to Refrigerated cooling by paying $5,844
2) Is it worth to upgrade to Brivis Zone Plus in a single storey 29 squares home by paying $1,604.00 for 2 zones. Read somewhere that zoning may not effective in single storey house and anytime at least 6 vents should be open for smooth working of the Gas heating.
3) Is it beneficial to upgrade the gas heating unit to 6 star ( $1,834.00 ) with no zoning and then have Evaporative cooling.

It is will be very helpful if you could provide your suggestions based on your experience.

Thanks,
Shi

Steve4216 · Nov 20, 2019 1:46 pm

This kind of stuff really is personal preference. I have lived with Evaporative cooling most my life, and only a short part of my life with reverse cycle cooling. It'd take a lot more then $6000 for me to build with Evaporative cooling again.

Blacktea2sugars · Nov 20, 2019 3:25 pm

I detest Evap cooling with a passion, and have never found it adequate.

That being said, depends on location, house construction materials and insulation (reflection of heat etc)
Window glazing and curtains/blinds also come into play
What are the breezes like? Being single storey, if you have dbl storey neighbours, will you miss out on cooling winds?

If it was my budget, I'd do Refrig with option 2 included. Yes I'm sure it will be RC, so you can heat as well.

Shi · Nov 20, 2019 3:34 pm

Blacktea2sugars

I detest Evap cooling with a passion, and have never found it adequate.

That being said, depends on location, house construction materials and insulation (reflection of heat etc)
Window glazing and curtains/blinds also come into play
What are the breezes like? Being single storey, if you have dbl storey neighbours, will you miss out on cooling winds?

If it was my budget, I'd do Refrig with option 2 included. Yes I'm sure it will be RC, so you can heat as well.

Thank you. I will have double glazing throughout. Its melbourne, at least 10 km areal distance from sea.

amilelka · Nov 20, 2019 3:41 pm

I'm under the impression that the cost of heating by gas is quite high. I would recommend reverse cycle ducted air conditioning.

Blacktea2sugars · Nov 20, 2019 6:35 pm

Shi

Blacktea2sugars

I detest Evap cooling with a passion, and have never found it adequate.

That being said, depends on location, house construction materials and insulation (reflection of heat etc)
Window glazing and curtains/blinds also come into play
What are the breezes like? Being single storey, if you have dbl storey neighbours, will you miss out on cooling winds?

If it was my budget, I'd do Refrig with option 2 included. Yes I'm sure it will be RC, so you can heat as well.

Thank you. I will have double glazing throughout. Its melbourne, at least 10 km areal distance from sea.

Ah ok
I'm also in Melbourne, less than 500 metres from the bay, and I still would not trust Evap to cool a double glazed double storey 40 + square house.

Bebbsy · Nov 21, 2019 8:03 am

amilelka

I'm under the impression that the cost of heating by gas is quite high. I would recommend reverse cycle ducted air conditioning.

I agree with the above. Having always had evaporative cooling and gas heating in our previous homes, this time we opted for a ducted reverse cycle system to heat and cool the home, and solar panels to help with running costs.

And on a personal level, as I get older I find my tolerance to extreme heat is a lot less than it ever used to be, so that sealed the decision.

Althom · Nov 21, 2019 10:55 am

Melbourne is too humid in summer for Evaporative to be effective.
Gas heating is expensive.
RC ducted air con is the most energy/cost efficient.

Shi · Nov 21, 2019 1:18 pm

Thank you all for the reply.

The problem here is my builder provides Brivis Gas heating + Evaporative cooling as a default option. And then the upgrade option is to a 14.80 kW (Nominal cooling capacity) single phase Brivis add on refrigerated air conditioning, which is Brivis ICE ( Integrated Cooling Equipment). Brivis advertise it as DualComfort - Brivis Gas heating + Brivis ICE. Firstly, I am not a big fan of Brivis, then when I check for user opinions, everyone has hell lots of issues with Brivis ICE cooling. Other confusion is because its combined with gas heating, does that mean it is not capable of reverse cycle heating? also Brivi's AEER ratings for refrigerative cooling is merely around 3.1 and I will endup paying $15,135 for Brivis Gas heating + Brivis ICE.

What are the other options? Do you know how much would be the rough estimate for Actron, Panasonic, Samsung, Daikin etc (or any better brands) to have reverse cycle cooling/heating on 29 squares single storey, 2740mm ceiling height, double glazed house based on your experience. Is that something doable altogether post the build?

Thanks,
Sreejith

ourrawsonbalmoral38 · Nov 21, 2019 1:53 pm

Shi

Thank you all for the reply.

The problem here is my builder provides Brivis Gas heating + Evaporative cooling as a default and the option. And then the upgrade option is to a 14.80 kW (Nominal cooling capacity) single phase Brivis add on refrigerated air conditioning, which is Brivis ICE ( Integrated Cooling Equipment). Brivis advertise it as DualComfort - Brivis Gas heating + Brivis ICE. Firstly, I am not a big fan of Brivis, then when I check for user opinions, everyone has hell lots of issues with Brivis ICE cooling. Other confusion is because its combined with gas heating, does that mean it is not capable of reverse cycle heating? also Brivi's AEER ratings for refrigerative cooling is merely around 3.1 and I will endup paying $15,135 for Brivis Gas heating + Brivis ICE.

What are the other options? Do you know how much would be the rough estimate for Actron, Panasonic, Samsung, Daikin etc (or any better brands) to have reverse cycle cooling/heating on 29 squares single storey, 2740mm ceiling height, double glazed house based on your experience. Is that something doable altogether post the build?

Thanks,
Sreejith

You said before that you will be mainly be using two rooms.

Perhaps you could put ceiling fans in bedrooms and split systems in areas you'd like heated/cooled?

brokenstick · Nov 21, 2019 3:11 pm

We just did KDR in Melbourne, and our temporary rental had Evap. I am so glad we didn't put it in - it was terrible. Didn't do much on those really hot 40 deg + days, except making it really humid inside.

Strongly recommend going for zones, so that you don't have to heat/cool the whole house - I am so glad we did

darb74 · Nov 21, 2019 5:54 pm

Hi,

I think you are much better off going with some individual split systems (ie. no ducting). When people talk about zoning, we have the ultimate 'zoned' solution with our 3 Fujitsu splits. We spent around $6500 (incl. rebate) to buy and get the 3 units installed during our build. Our place is single story, living areas total around 25 squares.

There are so many reason to go with multiple splits and the only negative I can think of is the aesthetics of the outside condensors.

The positives are:

Individual splits are the most efficient units (ie. highest COPs)
Ultimate zoning capability (simply turn on what units you wish to run)
Great redundancy in case of failure.....if you lose a unit it's only one, not your whole system!

Running any form of ducted heating/cooling in unconditioned roof spaces obviously leads to fairly large energy losses, but I will put my hand up here and point out we did retain our gas central ducted heating system. The builder was offering such a low credit to remove it, it wasn't worth it.

We have been in the house for about a month and the splits haven't had to be used too much but I can't see us using the ducted system much at all. Maybe we might turn it on to help distribute conditioned air (by the main 7.1kw split in the living area) around the rest of the house...as our central gas unit has a fan only mode.

Anyhow, if you have to go with a centralised ducted system I would certainly attempt to stay full electric and at least with a reverse cycle system (inverter) they are reasonably efficient.

ssyi · Dec 03, 2019 11:10 pm

Hello all, I am new to the forum and started with a thread asking for a cooling related help and no one provide me with the help. Posting the same question here hoping someone will be able help me.

I am planning to opt out gas heating and evaporative cooling provided by builder and go completely with reverse cycle refrigerative cooling post the build. Is this got any implications with Builder approval? Is there any rule that ducted Gas or some sort of heating should be there in place for building approval?

Thanks

darb74 · Dec 04, 2019 8:02 am

ssyi

Hello all, I am new to the forum and started with a thread asking for a cooling related help and no one provide me with the help. Posting the same question here hoping someone will be able help me.

I am planning to opt out gas heating and evaporative cooling provided by builder and go completely with reverse cycle refrigerative cooling post the build. Is this got any implications with Builder approval? Is there any rule that ducted Gas or some sort of heating should be there in place for building approval?

Thanks

As long as your energy rater (as in the 'builder's' energy rater) is OK with leaving off any mechanical systems - which I think is ok from a star rating perspective? - then I don't see a major issue. So basically if your builder is happy to credit you and the energy report doesn't include them either you should be ok.

I agree with leaving out ducted systems as they are typically quite inefficient with respect to energy loss via the ducts themselves. They also add penetrations to your ceiling and air return etc.

The main thing I would consider is getting this added to your plans/contract as 'owner supplied', so at least you can get the system(s) rough-in all done during construction which is not only cheaper but also much neater/easier.

We had 3 separate splits installed during our build and I am glad we did the rough-in at frame stage. It gave us the chance to choose exactly where the drains were located and seal up tears in wall wrap etc.

In my opinion now with having our house finished with a ducted gas heating system and also our 3 splits.....I believe our construction industry should ditch ducted systems completely unless they can somehow work out how to run the ducts through a conditioned air space. Multiple splits are the ultimate in zoning and efficiency and we are very happy with ours and wish I had pushed harder to have the central heating system deleted during our design phase.

Shi · Dec 08, 2019 1:14 am

darb74

ssyi

Hello all, I am new to the forum and started with a thread asking for a cooling related help and no one provide me with the help. Posting the same question here hoping someone will be able help me.

I am planning to opt out gas heating and evaporative cooling provided by builder and go completely with reverse cycle refrigerative cooling post the build. Is this got any implications with Builder approval? Is there any rule that ducted Gas or some sort of heating should be there in place for building approval?

Thanks

As long as your energy rater (as in the 'builder's' energy rater) is OK with leaving off any mechanical systems - which I think is ok from a star rating perspective? - then I don't see a major issue. So basically if your builder is happy to credit you and the energy report doesn't include them either you should be ok.

I agree with leaving out ducted systems as they are typically quite inefficient with respect to energy loss via the ducts themselves. They also add penetrations to your ceiling and air return etc.

The main thing I would consider is getting this added to your plans/contract as 'owner supplied', so at least you can get the system(s) rough-in all done during construction which is not only cheaper but also much neater/easier.

We had 3 separate splits installed during our build and I am glad we did the rough-in at frame stage. It gave us the chance to choose exactly where the drains were located and seal up tears in wall wrap etc.

In my opinion now with having our house finished with a ducted gas heating system and also our 3 splits.....I believe our construction industry should ditch ducted systems completely unless they can somehow work out how to run the ducts through a conditioned air space. Multiple splits are the ultimate in zoning and efficiency and we are very happy with ours and wish I had pushed harder to have the central heating system deleted during our design phase.

Thanks a lot darb74

Shi · Dec 08, 2019 1:14 am

darb74

ssyi

Hello all, I am new to the forum and started with a thread asking for a cooling related help and no one provide me with the help. Posting the same question here hoping someone will be able help me.

I am planning to opt out gas heating and evaporative cooling provided by builder and go completely with reverse cycle refrigerative cooling post the build. Is this got any implications with Builder approval? Is there any rule that ducted Gas or some sort of heating should be there in place for building approval?

Thanks

As long as your energy rater (as in the 'builder's' energy rater) is OK with leaving off any mechanical systems - which I think is ok from a star rating perspective? - then I don't see a major issue. So basically if your builder is happy to credit you and the energy report doesn't include them either you should be ok.

I agree with leaving out ducted systems as they are typically quite inefficient with respect to energy loss via the ducts themselves. They also add penetrations to your ceiling and air return etc.

The main thing I would consider is getting this added to your plans/contract as 'owner supplied', so at least you can get the system(s) rough-in all done during construction which is not only cheaper but also much neater/easier.

We had 3 separate splits installed during our build and I am glad we did the rough-in at frame stage. It gave us the chance to choose exactly where the drains were located and seal up tears in wall wrap etc.

In my opinion now with having our house finished with a ducted gas heating system and also our 3 splits.....I believe our construction industry should ditch ducted systems completely unless they can somehow work out how to run the ducts through a conditioned air space. Multiple splits are the ultimate in zoning and efficiency and we are very happy with ours and wish I had pushed harder to have the central heating system deleted during our design phase.

Thanks a lot darb74