Are air fryers more energy efficient than an oven or microwave?

Posted by Ross Lammas

Welcome to the world of Doll’s House energy-efficient cooking! Well, that’s the first impression of operating an Air Fryer; it’s tiny and compact. Not something you’re going to use for cooking this year’s Christmas turkey — that said, it could be handy for a whole manner of other tasty morsels if your oven is full. And very convenient for energy-saving cooking for smaller households this winter.

Air Fryers Energy Efficiency is all about size — and a big fan.

Size is what gives Air Fryers an advantage over your standard fan oven. In simple terms, it’s just a tiny space to heat up — combined with a more powerful fan distributing the heat more efficiently. Not much rocket science going on here! Unfortunately, there doesn’t appear to be much insulation to retain heat, which would make Air Fryers even more efficient. In addition, double-glazed doors could add yet more efficiencies. Nevertheless, this relatively inexpensive kit could aid your energy-saving arsenal this winter. Even so, if you have a double oven with a smaller fan-assisted mini oven, the savings of an Air Fryer may not stack up unless you use them regularly.

Does it look good in the kitchen?

The unit we tested was the Tower 11-litre T17076 rated input 2kW. The first impressions were good, and it looks well made. The overall design sat well in our kitchen. All the controls are touch sensitive. No buttons to trap dirt, and very easy to keep the outside clean. Included in the box was a confusing array of attachments. The manual explains these well, but it did seem odd that the basket is an optional extra. The mains cable seemed a tad short, but it worked for us.

What’s an Air Fryer like to use?

The test unit came with an excellent recipe book with a host of things you can do with an Air Fryer. Who’d of thought you could fry–up a cake! Or even a pineapple upside-down pudding. These machines certainly offer a flexible, efficient way of cooking. Yet, the name Air Fryer is a bit confusing. Basically, it’s a mini oven with a fan which uses less oil to produce crispy chips than a deep fat fryer. Turn to YouTube, and you’ll find a host of instructional videos to give you an idea of how an Air fryer works and recipe ideas. We were a little unsure which cooking accessories it was best to use — non-stick appears the preferred choice. However, after a needlessly nervous start — it proved very simple to operate, and soon we had cooked up meatballs, fried potatoes, and even experimented with flapjack. It proved perfect for quickly roasting tomatoes for a pasta sauce and was fab at baking a crispy potato. A minor niggle was that the on/off/pause touch button didn’t always respond quickly. Also, On the plus side, the air fryer is effortless to clean, with the trays small enough to fit in the dishwasher.

Air Fryers — how do the energy costs stack up compared to a small conventional oven or Microwave?

So, we compared baking one 240g potato in three different ovens, an Air Fryer, Small Mini (non-fan) oven and a Microwave, to evaluate the energy usage, time and taste/texture. The cooking costs are calculated using the Energy Price Guarantee (October 2022) of 34p per kWh.

Standard top (mini) oven

Firstly a Standard top (mini) oven with no fan. The cooking time was 70 minutes, and the result was excellent — crispy skin and an evenly cooked fluffy potato

Energy usage 1.10 kWh
70 minutes of cooking time @ 200 C
Cost to cook £0.374 (37p)

Air Fryer

The Air Fryer took slightly less time than the standard oven, only saving 10 minutes. Nevertheless, again the result was tasty, lovely and crisp.

Energy usage 0.80 kWh
60 minutes of cooking time @ 200 C
Cost to cook £0.272 (27p)

We did note that the Air fryer rating was 2kW. Yet whilst testing, it appeared to peaked at 2.2kW. The thermostat within the unit worked well, running at around 2145W to 2200W for 30 seconds and then switching to fan mode for 60 seconds at 36W.

Microwave

Our Microwave certainly wins on the energy-saving front! The machine used was 900W rated — and used about 1500W during the test. It only took 8 minutes to cook. Remarkably, only using 0.20 kWh!

Energy usage 0.20 kWh
8 minutes of cooking time @ 900W
Cost to cook £0.068 (7p)

As expected, the results were slightly disappointing, with no crisp skin. However, the potato was wonderfully fluffy on the inside. Our solution was to pop it in the Air Fryer for a ten-minute blast at 200 C, resulting in a perfectly baked spud for an extra few pennies (5p).

Would I buy an Air fryer?

Like many kitchen gadgets, you ask, do I need more clutter? Will it sit in the cupboard with the juicer, bread machine and pasta maker? Do I need one? Well, it depends; if you’re looking for a quick and efficient way of cooking meals and have a smaller household, an Air Fryer could be a handy addition, or you’re a student wanting to cook some less fatty chips on a small budget. These machines are a real winner. While, of course, the advantages may be less compelling if you’ve already got a double oven with a small fan oven. The real energy-saving winner is a microwave, perhaps with an Air Fryer for the crisper morsels.

Nevertheless, it does seem that cooker manufacturers have missed a trick here. Indeed there appears to be a market for small built-in fryers in conventional double-ovens or even triple cooker setups. Small ovens for quick use certainly make a lot of sense.

Are there Energy labels for Air fryers?

The other thing to remember is that these machines do not require energy labels. So comparing like-for-like models from a pure energy efficiency standpoint is somewhat challenging. Though overall, it’s excellent to see innovation in this sector. It is even better if it helps consumers save energy and drives more innovation in cooking more energy efficiently.

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Do Heat Pumps save you money and are they reliable?

Posted by Ross Lammas

Heat pumps are the mainstay of UK government policy in decarbonising our home heating. Currently, 95% of UK housing stock is heated by fossil fuels, mostly gas. Yet, the energy crisis has highlighted the need for us to move away from the volatile energy markets whilst delivering UK’s Net Zero promises. The electricity grid has become greener due to the expansion of renewable generation, making heating with electricity, ideally, heat pumps the quickest solution to us weaning off hydrocarbons. By 2025 installing a new gas boiler will become a thing of the past. So, the big question for a homeowner is, are heat pumps any good?

Longevity and reliability of installed heat pumps

I must admit I’ve been holding off writing this blog post. Why? I didn’t fancy tempting fate whilst talking about the reliability of our heat pump. So, having fitted a heat pump in 2005 here’s my experience living with electric heating.

Why choose a heat pump? The options are limiting for those heating rural homes

Living in a rural location doesn’t give you many alternatives to how you heat your house. It’s oil, LPG, solid fuel or electricity. Unfortunately, mains gas, the most affordable option, is a non-starter. Our last home was heated by oil, which was unreliable — often breaking down just before Christmas! In addition, the maintenance regime was onerous and expensive. We often struggled to get an engineer to visit when it had broken down. Then there was the fuel. It’s smelly and unpleasant to handle and not that easy to store. The other disadvantage was the volatility of the oil price. The per litre price of oil would often double overnight, then drop the next week back to normal. So buying heating was a game of outguessing the energy market.

At this time, my workplace was heated by electric storage heaters. These were the large block-filled units heated at night on Economy 7 tariffs. The issue with these — apart from the enormous bills — was they ran out of warmth by 4 pm on a cold winter’s day. In an office environment, this was manageable. However, if you return home in the evening after work, returning to a home that’s chilling off isn’t ideal. Also, storage heaters were inflexible, expensive and took up precious space.

A new build was an option to rethink our home heating requirements

Building a home from scratch opens up many possibilities. Put off by having lived in many inefficient, cold, and drafty homes, we were looking for a hassle-free and reasonable-cost solution heating system for our new build. The house was going to be well insulated, making the heating demand reasonably low, but it still needed to meet the needs of a family — plenty of hot water, etc.

The cheapest option at the time was an oil combi boiler. Yet, after extensive research, a Ground Source Heat Pump looked like a good option, especially as we had space around the building to install the ground loop. These are pipes buried in the ground or placed in a pond, even submerged in a well. They act as heat transfers, extracting the dormant heat from the ground. Air source heat pumps use air to do this, which is less efficient. Despite this, they are still much more energy-efficient than direct electric heating. And much greener than gas or oil.

You need to get your plumbing right for heat pumps

The intention was to install underfloor heating, which works well with heat pumps. Conventional radiators heated the upstairs; these were slightly oversized as heat pumps to heat the water at a lower temperature than gas or oil boilers. It’s worth checking if you’re retrofitting a heat pump to review that your radiators are adequately sized. And don’t forget that you’ll need a hot water tank. Heat pumps don’t work like combi-boilers. I believe microbore plumbing pipes aren’t suitable for heat pumps. Best to check with a registered installer first.

Our heat pump installation was straightforward, in some ways, more manageable than a conventional boiler, as the whole unit is self-contained with a built-in hot water tank. Unlike air source heat pumps, the kit is installed inside the house. They hardly make any noise either, certainly less than a combi boiler.

We had some issues regarding the energy required to start the heat pump. At one stage, it was thought we might need a three-phase electricity supply. Luckily, a system called soft-start resolved this.

I admit concerns that the system would not generate enough hot water for our family whilst heating the house. An instant electric shower was installed as a backup. These fears have been unfounded. Even with a whole house of guests in mid-winter, the heat pump has worked faultlessly.

Get the thermostatic controls sorted

The thermostatic controls are excellent on our IVT Greenline HT. Unlike conventional heating systems, there is a thermostat outside the building. Which talks to the thermostat inside, monitoring the temperature difference and balancing the heating requirements. We often wake up not knowing the temperature has dropped at night. Set up when installed; this has been running for many years.

Are heat pumps green?

So was a heat pump the right choice? It was undoubtedly the greenest choice; without us doing anything, our emissions have declined. Why? In the UK, electricity in 2005 was generated by 22% from zero-carbon sources, and in April 2021 jumped to 40%. Therefore, we’ve reduced our heating emissions by 18%, with or without buying a so-called REGO green energy tariff.

Will a heat pump save you money?

There are a lot of misconceptions regarding heat pump technology. People seem to think energy is free, especially with ground source systems. Some believe we’ve somehow drilled into the earth’s core and are extracting heat. However, the alchemy of heat pumps is for every unit kWh you put in; you get between 3 and 2.5 times the energy out.

But, economically, fuel cost terms saving are challenging to quantify. For example, a ground source heat pump is nearly three times more efficient (air-source pumps are 2.5) than direct electric heating.

Nevertheless, electricity is three times more expensive than mains gas — making the saving reasonably balanced compared to gas. On the other hand, LPG is considerably more costly, especially if you can get locked into single supplier contracts. While heating oil prices are volatile over the instalment period, prices have gone from 23p lows in 2016, 20p in the pandemic, to nearly £1.60-litre pecks this year!

Will a heat pump improve your EPC (Energy Performance Certificate)?

Perversely, our Energy Performance Certificate (EPC) penalised our heat pump because it has an immersion tank. This assumes it’s being heated directly from electricity, it’s not. Ninety-nine per cent of the time the heat pump is warming the water. It recommends installing solar thermal water heating, even though it’s extracting heating from the ground and is powered by solar PV in the summer. Oddly, EPCs don’t recommend heat pumps. Our house could be A-rated EPC if we took out the heat pump! Madness.

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Are Ground Source Heat Pumps reliable?

The essential factor that makes heat pumps real winners is maintenance. Conventional boilers need servicing every year, which is expensive. They tend to go wrong regularly — especially oil ones.

So far, our IVT Greenline heat pump has run faultlessly for 18 years! Which is more than I can say for my car or home appliances.

Are you thinking of getting a heat pump — can you get grants?

Yes, homeowners and small businesses in England and Wales can apply for grants to replace their oil and gas boilers. Under the scheme, which will run for three years, property owners will be able to get the following:

£5,000 off the cost and installation of an air source heat pump
£5,000 off the price and installation of a biomass boiler
£6,000 off the expense and fitting a ground source heat pump

Is a heat pump suitable for your home?

There’s a tool to help homeowners and businesses make better-informed choices about the suitability of installing a heat pump. It details the different types of heat pumps, their costs and carbon emission savings, and helpful guidance about what modifications might be needed to make a home right for a heat pump.

Removing black mould and preventing condensation

Posted by Ross Lammas

We’re all being encouraged to insulate, and draft exclude our homes, which is excellent for reducing energy bills. However, this can be bad for your health if condensation starts causing black mould, which can be potentially hazardous to the very young or elderly. Seal up your home too much, without suitable ventilation, and you will suffer from condensation (water evaporating on cold surfaces), creating damp patches and eventually mould.

Airbricks and trickle vents allow buildings to ventilate naturally

The modern approach to preventing condensation is to have trickle vents fitted into double glassing frames, allowing moisture to escape the building. It may sound counterintuitive to leave these open in cold weather; however, this is when you will need these open the most! Building regulations stipulate that extractor fans are fitted to rooms that generate the most moisture, such as kitchens and bathrooms.

Properties built post-150 years ago tend to have airbricks fitted; these allow the building to ventilate naturally. The golden rule here is not to block them up! Yes, they can be draughty, but they are doing an essential job – preventing dampness. Retrofitting modern draught-preventing vents such as the Passyfier products are a great solution and can be installed by an experienced DIYer. I’ve used these products in renovation projects and new builds and found them to be a very cost-effective, simple solution.

Older homes built with traditional materials such as lime mortars and timber frames will breath naturally, unlike buildings built with modern cement products. If you live in a home that’s over 150 years old and it’s rendered with a cement-based product, and the walls appear damp, it could well be due to the building not being able to breath properly. Replacing this with a lime render should help the building breath during the changing seasons.

Dehumidifiers Electricity Cost Calculator

Ensure your extractor fans are working correctly

The most significant source of water vapour in your home is from your kitchen, cooking, boiling kettles and laundry appliances. Next is your bathroom – showers produce masses of steam which condenses very quickly. It’s vital to ensure your extractor fans are working correctly. If you live in a rented property, your landlord should maintain these as they are part of building regulations.

How to choose a tumble dryer

Drying clothes on radiators releases yet more moisture into your home, so hang out your washing if you can. Or if you have a tumble dryer, make sure that your ventilation is working correctly.

A dehumidifier can help reduce moisture

An electric dehumidifier can help reduce moisture, working similarly to a domestic refrigerator to chill the air and condense excess moisture. The dry air is then pumped into room temperature before leaving the machine. Water is collected in a reservoir, which has to be emptied periodically. They also give off a small amount of heat and effectively create background heating. They can be noisy though and consume electricity!

Electricity Cost Calculator

Tips on how to control black mould and prevent condensation

Keep trickle vents or a small window slightly open (use window locks for security)
Don’t block up airbricks
Ventilate bathrooms and kitchens – don’t turn off extractor fans!
Keep bathroom and kitchen doors closed
Cover pans while cooking (saves energy, too), and don’t leave kettles boiling.
Dry your washing outside whenever you can
If necessary, use a condenser tumble dryer or vent your tumble dryer outside as per the manufacturer’s guidance.
Be aware that portable gas heaters (flueless) create water vapour
A dehumidifier may help – they do use more energy though

Removing Black Mould

Clean areas affected with a fungicidal mould-killing product. Make sure it carries a Health and Safety Executive “approval number”. Follow the manufacturer’s instructions carefully.
Remove the lining and affected wallpaper, treat the plaster and then redecorate using fungicidal paint or sealant.

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Heatwave – How much electricity does a portable air conditioning unit use?

Posted by Ross Lammas

Heatwave! Temperatures are set to soar yet again, with forecasters predicting record highs – another summer in which keeping cool is a problem!

There has certainly been a rush for fans in the shops this year, with portable air conditioner units becoming the ‘must-have’ item this summer to cool an office or your home. So how do they work? And more importantly how much do they cost to run?

An air conditioner works in the same way as your fridge, cooling your room by passing warm air over a cold evaporator coil, and then blowing cooled air into your room. This process also generates hot air that needs to be vented out of the building by an exhaust hose, usually placed through a window. Another often forgotten element of this cooling process is that it generates water and dries the air, that’s why portable air conditioning units have water tanks that need to be emptied.

How do I keep my room cool and my air conditioning unit running efficiently?

Carrying on the fridge theme… if you think of your room as a fridge, the last thing you’d do is leave the fridge door open, the same applies to the room you’re trying to cool. Keep your space well sealed by closing doors and windows, this will ensure you get the best out of the air con unit. Closing blinds and curtains will reduce the heat from sunshine through windows and doors. Good levels of insulation will help keep rooms cooler in summer, as well as warmer in winter. Hot summers may be a rare experience for the UK, but travel to Europe – France, Spain, or Italy and you’ll find plenty of external shutters preventing the sun’s heat from entering the room.

What do you look for when buying an air conditioner?

A thermostat is pretty crucial! You don’t want to waste energy trying to get your room too cold, and a timer is a good bet also. Like other electrical appliances, air conditioners have energy efficiency labels, graded from A to G for energy efficiency; go for the best you can afford and save long-term. Washable pre-filters and odour-eating carbon filters are useful features.

Electricity Cost Calculator

How much do they cost to run? Just check the power consumption figures, then use Sust-it’s energy cost calculator to see what that will cost to run per hour. Click here to see the potential air conditioner running costs.

Air Conditioning Units ranked by annual running cost

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Reluctantly, I’ve given up on long-distance electric vehicle journeys

Posted by Ross Lammas

Like most drivers, the majority of my car journeys are relatively short. Meetings, deliveries, trips to the shops, ferrying children around, going to friends and family. For these journeys, an electric vehicle (EV) is brilliant. Particularly as we’ve off-road parking and charging at home.

Over the past six years, electric vehicle ownership for myself has been good for my wallet and the planet (hopefully!). Even long excursions were possible with planning, a handful of charging network membership cards, and a phone full of EV charging apps!

Electric vehicles, victims of their success

Now, electric cars are becoming mainstream must-haves for company tax-efficient motoring — or those looking to reduce their carbon footprint. The economic argument evolves even more with fuel prices going through the roof. Those who have no interest in NetZero or carbon reduction are looking at going electric, and why not? They are excellent to drive and cheap to run if you’re charging from home on off-peak electricity. Just think of all that money you’ll save to spend on short-haul flights and patio heaters!

Range anxiety, no, it’s charger rage!

Range anxiety is no longer the primary concern; now it’s finding a charger that hasn’t got a plug-in hybrid in it! Why do drivers who have a perfectly working internal combustion engine still feel the need to plug in their vehicle? Then there’s the; I’m nearly fully charged, but they still feel the need to top up their EVs and leave it charging for hours whilst shopping! Finally, what happens when you’re on a long journey in a pure electric car… should you hang around to see if the driver turns up? Especially when you’ve got ten miles left in the battery. Do you risk driving five miles up the road to see if there’s a charger free? Can you trust what the EV charger app map is telling you? If you get there, will there be a row of SUVs, which all look the size of buses — I thought lighter and aerodynamic vehicles were more efficient, stacking up for the next charging slot.

And this is when you’ve rerouted because the motorway services charging network is inadequate. Is this because the electricity infrastructure is in the wrong place? Or that the monopoly players are holding on to their assets?

Long journeys turn into nightmares very quickly

The upshot, a journey that should take three or four hours, takes seven or eight! Sorry, I’m late for the meeting. Could we reschedule for tomorrow morning whilst I find a free charging space?

Even a trip to the Capital, which appears to have chargers everywhere, turned into misery. It took over two and half hours to find (A) a charger that worked or (B) one that let non-residents use it. Even spotting the charge points isn’t easy; why not have standard signage highlighting their whereabouts? It’s incredibly stressful when you have a deadline and goods to deliver.

Electric cars make fantastic runarounds

The reality of EV ownership is very mixed; yes, they make competent second cars for dashing around, especially if you’ve off-street charging. On the other hand, lengthier journeys are achievable if you can afford an EV with a tonne of batteries. It seems counterintuitive; why lug a mass of weight everywhere for that infrequent longer trip — how can that be efficient?

Ten times more en route, rapid chargers are required to support long-distance journeys

An independent report from the Electric Vehicle Energy Taskforce has forecasted a whopping 500,000 public charge points need to be deployed by 2035. (Currently, we have 30,000 in 2022). To give drivers the faith to buy electric vehicles and the means to charge them. Half of these (250,000) will support drivers in homes without off-street parking. However, will it be feasible to let the market sort out the charging infrastructure? What’s the commercial incentive to install street chargers that only deliver 3 or 7kWh per hour if income is only 50p per unit of electricity. That’s £1.75 to £3.50 an hour before you’ve even paid for the wholesale electricity. Not to mention installation expenses, upkeep and real estate expenditures.

Electric car driving cost advantages will diminish over time

The price advantage of EV driving will take a hit, too, with the report highlighting that household charging prices will be 25% higher without smart charging — and that’s before road pricing kicks in. In addition, the cost of en-route charging is escalating at the moment, with some networks charging £0.71 per/kWh, compared to the energy price cap of £0.28p per/kWh, or home smart off-peak charging tariffs at just 8p per/kWh

The EV charging network is improving rapidly, though nowhere near quick enough to keep up with demand. Hence, I’m looking for an alternative for those longer drives until the charging grid improves.

What should policymakers do to make travel greener?

It’s a chicken and egg situation — if you encourage electric car ownership and wait for the infrastructure, you’ll risk frustrating drivers who’ll turn back to conventional combustion engines. But conversely, it will be a lengthy wait for the infrastructure as the grid can’t currently cope with the growing demand for electric charging. So, put more resources into public transport, cycling-friendly options and encourage car sharing, particularly in urban areas. Learn lessons from the pandemic — encourage flexible working and fewer car journeys as the greenest option. And don’t hoodwink the public that simply buying an electric car will be easy!

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Air Fryers Energy Efficiency is all about size — and a big fan.

Does it look good in the kitchen?

What’s an Air Fryer like to use?

Air Fryers — how do the energy costs stack up compared to a small conventional oven or Microwave?

Standard top (mini) oven

Air Fryer

Microwave

Would I buy an Air fryer?

Are there Energy labels for Air fryers?

Longevity and reliability of installed heat pumps

Why choose a heat pump? The options are limiting for those heating rural homes

A new build was an option to rethink our home heating requirements

You need to get your plumbing right for heat pumps

Get the thermostatic controls sorted

Are heat pumps green?

Will a heat pump save you money?

Will a heat pump improve your EPC (Energy Performance Certificate)?

Are Ground Source Heat Pumps reliable?

Are you thinking of getting a heat pump — can you get grants?

Is a heat pump suitable for your home?

Airbricks and trickle vents allow buildings to ventilate naturally

Ensure your extractor fans are working correctly

A dehumidifier can help reduce moisture

Tips on how to control black mould and prevent condensation

Removing Black Mould

How do I keep my room cool and my air conditioning unit running efficiently?

What do you look for when buying an air conditioner?

See the most energy efficient...

Electric vehicles, victims of their success

Range anxiety, no, it’s charger rage!

Long journeys turn into nightmares very quickly

Electric cars make fantastic runarounds

Ten times more en route, rapid chargers are required to support long-distance journeys

Electric car driving cost advantages will diminish over time

What should policymakers do to make travel greener?

Energy Efficient Living — News, Hints & Tips