iStore vs Emerald: Which Heat Pump Is Better? (2026)
Quick Verdict
Emerald is the more efficient choice with a higher COP rating, meaning lower running costs over time.
Side-by-Side Comparison
| Feature | iStore | Emerald |
|---|---|---|
| Price range (installed) | $2,800 - $4,400 | $2,750 - $3,750Lower |
| COP (efficiency) | 3.2 | 5.2Higher |
| Tank warranty | 5 years | 7 yearsLonger |
| Compressor warranty | 5 years | 5 years |
| Noise level | 49dB | 49dB |
| Annual running cost | ~$370/yr | ~$228/yrLower |
| Refrigerant type | R134a | R134a |
| Country of manufacture | Australia | Australia |
| Australian made | No | No |
| Best for | Budget-conscious households wanting maximum rebate impact and simple installation | Households wanting a high published efficiency and a long tank warranty without paying split-system prices |
Price Comparison
iStore starts from $2,800 installed (before rebates), while Emerald starts from $2,750. That is a difference of roughly $50 at the entry level. Emerald is the more budget-friendly option upfront, though iStore may deliver savings through lower running costs over time. Both prices are for fully installed systems before government rebates and STCs, which can reduce the out-of-pocket cost by $1,000 to $3,000 depending on your state.
Efficiency Comparison
COP (Coefficient of Performance) is the key efficiency metric for heat pumps. A higher COP means more heat output per unit of electricity consumed. iStore achieves a COP of 3.2, while Emerald reaches 5.2. The Emerald is 63% more efficient, which translates to roughly $142 less per year in running costs. Over a 10-year lifespan, that efficiency advantage adds up to approximately $1,420 in savings.
Warranty Comparison
iStore offers a 5-year tank warranty and 5-year compressor warranty. Emerald offers a 7-year tank warranty and 5-year compressor warranty. The Emerald has the stronger warranty coverage with 7 years on the tank, giving you 2 extra years of protection compared to the iStore. A longer tank warranty can provide significant peace of mind, as the tank is the most expensive component to replace.
Noise Comparison
Noise is an important consideration, especially for suburban installations where the unit may be close to bedrooms or neighbouring properties. iStore publishes 49dB for its quietest model, and Emerald publishes 49dB. Both units produce the same noise level, so there is no difference in acoustic impact.
Climate Suitability
The type of refrigerant a heat pump uses significantly affects its performance in cold weather. iStore uses R134a refrigerant, while Emerald uses R134a. Both units use the same refrigerant type, so cold-weather performance should be comparable. R134a performs well in moderate climates but may lose some efficiency in very cold conditions.
Pros and Cons
iStore
Pros
- Most affordable option
- Australian owned and supported
- Simple installation
- Good rebate value (low cost means rebates cover more)
- Widely available
Cons
- Lower COP than premium brands
- Shorter warranty
- Noisier than split systems
- Higher running costs long-term
- Units manufactured overseas
Emerald
Pros
- Among the cheapest R290 units with a published COP above 4.8
- Pro series carries a 7-year tank warranty, 8 if you register it
- Two magnesium anodes on the Pro tank
- Widely stocked, so quotes are easy to compare
- Runs on the heat pump alone down to -7C
Cons
- Manufacturing location is not published
- Not on the Solar Victoria locally made list, so it earns the lower Victorian rebate tier
- The Select series drops to a 5-year tank and 2-year labour warranty
- Emerald quotes 39 to 40 dB from 3 metres on its web pages while the data sheets show 49 to 50 dB at 1 metre, so compare it with other brands at 1 metre
Which Should You Choose?
Choose iStore if...
- Budget-conscious households wanting maximum rebate impact and simple installation
Choose Emerald if...
- You want a lower upfront cost (from $2,750 vs $2,800)
- You want the best efficiency and lowest running costs (COP 5.2 vs 3.2)
- You want a longer tank warranty (7 years vs 5 years)
- You want lower annual running costs (~$228/yr vs ~$370/yr)
Buying in Victoria? Stack up to $2,700 in rebates
Whichever brand you pick, Victorian households can stack the Solar Victoria Hot Water Rebate ($1,000-$1,400), the Victorian Energy Upgrades discount ($500-$2,000), and federal STCs ($500-$1,200) ahead of the 1 March 2027 gas ban deadline.
Heat pump guides
- Every Australian heat pump rebate, with the dated changes
- The best heat pump hot water brands in Australia
- Heat pump hot water cost in Australia
- Victoria heat pump rebates
- New South Wales heat pump rebates
- Queensland heat pump rebates
- South Australia heat pump rebates
- Australian Capital Territory heat pump rebates
- Western Australia heat pump rebates
- Tasmania heat pump rebates
- Northern Territory heat pump rebates
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