The botched $5-million heating & cooling installation… and how to avoid it in your building
Five to six times a year, we have to do something really unpleasant. And we hate doing it.
People call us in to have a look at a heating & cooling system installed by somebody else.
And while we do really try to help as much as we can, to make it alright
… most of the time, it’s impossible.
The laws of physics just won’t allow it.
So we have to tell the client, the builder or the architect, that the system they had installed (by another company) is not going to work as they expected (or were sold).
It’s either not going to be as efficient as they anticipated.
Or provide the heat or chill they need.
And even worse, sometimes we have to tell them that it was a total waste of money, turn it off, and to make alternative plans (and call their lawyers).
So what’s the problem?
It usually starts off with a phone call…
Either during the construction phase, where the original contractor has lost the confidence of the client, builder or architect.
Or the call comes after everything is built and finished, but the results or performance are not there, and the original contractor has stopped answering their phone.
Sometimes the floor heating is not keeping the house warm.
Or the aircon is draughty and noisy.
Perhaps the heat pump is consuming too much power.
And the pool is freezing cold.
You get the idea…
Here’s the story of a botched HVAC installation in a new 5-million dollar house…
George’s Story ($429,000 down the drain)
Just a few weeks ago, George – a great builder in Perth (name changed) – called. He’s half way through building a spectacular ~$5 million-dollar house with fantastic views.
George’s client wanted not only a beautiful home, but also an energy efficient building.
So along with the heavily travertine clad floors and walls (with hand-picked Italian travertine), George had gone to plenty of trouble to include a lot of thick insulation in the walls, ceiling and roof to limit heat gains in summer and heat losses in winter. Double glazing throughout. And sealing of the building (to stop air infiltration).
And the client had from the very start of the project, said that he wanted a geothermal heating and cooling system for his house.
George found a contractor that seemed to offer what they needed, so the client gave them to go-ahead, and everything seemed to be off to a great start.
(The builder told me all of this a few weeks ago when I met him on site – about 14 months since they had first engaged the original contractor).
But George and the client had recently given the original contractor the axe, and called us upon a recommendation from a colleague.
On site George walked me through what had been already installed, and then sat me down to show me the system design.
And this was where the penny dropped.
There really was no design.
Just a few emails and some coloured lines drawn over a PDF site plan.
It was being put together on-the-go… The company was ‘winging’ a $429,000 project (what they had quoted).
So we sat down and went through the emails. We put together a drawing showing the proposed system design. And we did our own calculations.
What went wrong?
The main things found were:
- The geothermal system was undersized by 41%. This means that there would not be enough energy available to heat and cool when really needed during the peak of winter and summer.
- There were 7 heat pumps when 1 (at max 2) were required. Some machines were oversized. Some undersized. But this increased the overall power draw, decreased efficiency, and meant many of the machines were working against each other when operating simultaneously.
- The geothermal system had been configured in a basic ‘primary-loop’ configuration. Meaning every heat pump connected to the primary-loop after the first heat pump was working harder and harder at lower efficiency (Think of breathing into a bag… After every breath there is less oxygen available for the next breath).
- The aircon was OK. This was pretty much the only thing that was done right – because the subcontractor doing this part had done some planning.
- The list (unfortunately) goes on…
Now, this isn’t a total throwaway system. We are salvaging what we can for George and the client. But it’s going to cost the owner an extra $90K, and there are some elements of the system which are built-in and cannot be changed (unless there is some serious demolition work), meaning some efficiency is permanently lost.
But if the appropriate calculations were performed, and a detailed system design completed, the system would be not only sufficient for its purpose, but also much more energy efficient, and would have cost the client less money now (and at the beginning), and in future running costs.
So how do you avoid ending up with a dud system in your building too?
Make sure there is a detailed system design (drawings), based on specific data (calculations). Otherwise the contractor is basing your system on guesses, hopes (and maybe even dreams), and risking your money and future peace-of-mind.
But how much does getting a system calculation and design cost?
Well, it depends on the type and size of the system… There doesn’t have to be an up-front cost associated (but often for large or complex systems there can be a design fee).
There are 2 key factors to consider:
- The entire system should be designed by one engineer/company. Most often we see issues where a supplier/manufacturer provides a design for one part of the system (which may be technically sound), but then the other parts of the system are designed/calculated by someone else (and they don’t marry together), or worse, not designed or calculated at all… and the chain is only ever as strong as its weakest link.
- From experience, we recommend your system be designed by a professional that is suitably ‘qualified’ (tertiary degree), not just ‘certified’ (usually a 1-day training course). Every week we talk to people in our industry that don’t understand basic physics 🙁
Importantly: Ask to see the calculations and design before you commence with your project. From this you’ll get a good feeling of whether your contractor is on the right track.
How to avoid the common problems that reduce energy efficiency
Here’s a list of common problems we see that reduce energy efficiency (and cost $$$), that you should look out for:
- Poorly or not insulated pipework: Energy you paid to create is carelessly lost on the way to its destination, costing you more every hour. There are regulations stating what the minimum level of insulation your piping needs to adhere to specified in R-value.
- Equipment over or under sized: This leads to system instability and poor efficiency, meaning strange behaviour and higher running costs. Calculating the precise output required of the equipment allows for accurate sizing, and smooth operation.
- Poor control system: The system (or its parts) don’t work when they should, or are working when they shouldn’t. Worse is when different parts work against each other simultaneously (e.g. floor heat vs aircon cool). A control system designed before the start of a project allows for the right cabling to be run, and the logical control process be arranged so everything works together in perfect harmony.
- Heat pumps strangled: When a heat pump has a hard time collecting energy, it works at super low economy (costing you more) and shortens the lifespan (from ~15 years to just a few years). This can be an air/water heat pump in an enclosed space such as a garage. Or a geothermal heat pump with a small collector area. Even a water-source heat pump with a low flow rate. Accurate design from calculations, ensures your heat pump works at its best.
- Thermal bridges: Energy leaks very quickly through thermal bridges – they’re easy paths for energy to undesirably flow either from the outside to inside your building, or visa-versa. This results in having to pay to create extra energy to make up for the losses. By analysing the building plans with the architect thoroughly before construction commences, the thermal bridges can be identified and eliminated.
- Pumps incorrectly sized: Half the time they are too small, and therefore cannot deliver the energy required of them to the destination, resulting in patchy heating/cooling. The other half of the time they are too big, and are consuming too much electricity, reducing system efficiency. Calculating the required fluid flow and hydraulic losses allows for perfect pump sizing.
- Too-high or too-low water temperatures: In a heating system, the lower the water temperature, the more efficient the system and the lower the running cost (e.g. it takes less energy to create 40ºC water than 80ºC water). The inverse is true for cooling systems. Often heating/cooling systems are hastily put together, and mistakes/sloppy work are countered with increasing the water temperature, which costs you more each hour you run it. By purposely designing a low temperature system from the get go, you maximise your energy efficiency and lower your running costs.
- Small pipe diameters: Small pipes are often chosen as they are cheaper than larger diameter pipes. But they restrict the amount of water (and therefore energy) which can be delivered. Plus, they increase the amount of energy consumed by the pump (as its harder to push water through). This results in underperforming systems and higher running costs. Calculating the flow requirements and acceptable hydraulic losses allows the pipes to be sized perfectly.
- Heat recovery dream: Systems are often described as ‘heat-recovery’, yet when you analyse their operation, they only partially recover heat, or only recover heat on the off chance that another piece of equipment is operating at the same time. This type of working operation wastes you money. By designing the system with the right technology and controls, almost all energy can be recovered and reused effectively, saving you 30-50% on your energy costs.
Here’s is how a professional design should look
So that you have a base for comparison, professional drawings often look like this…
What now?
No matter who you choose to help with your heating/cooling project, we at Euroheat want your system to be a success. So here, below, are some specific guides for you, to make sure you too don’t end up with a poor performing and expensive system:
- Floor heating & cooling design for architects and builders. (currently restricted)
- The good, the bad, and the ugly: Geothermal systems. (being updated)
- How to include hydronic radiator heating into your home
- 5 common mistakes with floor heating to avoid
- Using heat recovery to save 30-50% on your energy bills. (coming soon)
- How to choose the right heat pump for your project. (coming soon)
- Insulation for your home – get it right the first time. (being updated)
- How to make your building naturally energy efficient. (currently restricted).
And if you do want Euroheat’s help to calculate, design and specify your heating/cooling system, one of our in-house engineers would be happy to help you with:
- Building thermal modelling.
- Integrated system design. (includes floor, aircon, tap hot water, pool, cellar, PV, etc.)
- Geothermal system design.
- Heat pump heating/cooling design.
- Floor heating/cooling design.
- Wall heating/cooling design.
- Ventilation design.
- Aircon heating/cooling design.
- Pool heating design.
- Tap Hot Water design.
- Central radiator heating design.
- Commercial process heating/cooling design.
If you’d like to create a totally natural feel and comfortable climate in your bulding, give us a call and we can have an introductory quick 15 min. consultation over the phone with you about your plans. To help you understand the process. To help you select the right building products or HVAC systems. And to answer any questions. We promise no salesy pitching, just info on physics, energy flows, thermal efficiencies and how to use it all in seamlessly heating/cooling your house… 08 6468 8895
If you´d like to get our detailed expert opinion and guidance, please see our expert consultation option here.