Selecting the right model means finding the perfect balance between client budget on the one hand and features and benefits on the other. It’s essential to get the right fit for your customer’s needs, while avoiding any over-spec.
So, what are the must-have technical attributes to look for when choosing a heat pump? What differentiates one heat pump manufacturer’s offering over another? We take a look at some of the key considerations.
Can it run at high temperatures?
A high flow temperature means a heat pump may be suitable for use in older buildings as well as in new-builds, while also providing superior hot water comfort. Furthermore, depending on the building’s heat loss calculations, it may be possible to retain the existing hot water cylinder and radiators, keeping costs and disruption to a minimum.
Most domestic heat pumps can reach flow temperatures of 55-60oC, but the highly popular Viessmann Vitocal 150-A and 151-A air source heat pumps have a maximum flow temperature of 70°C, even when outside temperatures fall to -10oC.
This aspect addresses the common narrative that homes with heat pumps won’t be warm enough.
Is it going to be quiet?
The Vitocal 150-A and 151-A air source heat pumps are both extremely quiet – 30 dB(A) at a 4 m distance – in operation thanks to Viessmann’s Super Silent Design. This means the heat pump can barely be heard.
Does it use environmentally-friendly refrigerants?
Given that cutting emissions is one of the biggest drivers for heat pump customers, this is a crucial consideration. Fluorinated hydrocarbons such as HFCs and PFCs are the most commonly used heat pump refrigerants. However, if they leak into the environment, they are thousands of times more harmful than CO2. Consequently, their use is becoming increasingly restricted with extensive regulations around leak testing, labelling and disposal.
Both the Viessmann Vitocal 150-A and 151-A air source heat pumps use a natural propane refrigerant called R290. This is one of the most climate-friendly and cost-effective available with a Global Warming Potential (GWP) of only 0.02 (compared to 1.0 for CO2).
Does it come with an integrated defrost buffer?
A buffer tank helps the heat pump’s defrost cycle by using heat from the buffer to facilitate defrosting instead of taking it from the home’s radiators. It therefore needs to be large enough to provide the energy needed to defrost the outdoor unit in cold weather.
If the defrost buffer is located inside the IDU, as in the case of the Viessmann Vitocal, the heat pump never fails to start, regardless of system temperature. It also ensures that a robust and complete defrosting can take place.
Does it control your flow rate automatically?
With a heat pump, you generally need the water to move round the heating circuit twice as quickly as with a gas boiler. If the flow rate drops, for example when radiator valves close, so does the system’s efficiency, greatly increasing running costs.
Look for systems that automatically control the flow volume in the heating circuit. As well as ensuring the heat pump is working optimally, this will greatly simplify its integration with existing systems.
The Vitocal 150-A and 151-A both come with Viessmann’s patented Hydro AutoControl® hydraulic system, which allows the heat pump to be operated reliably at maximum efficiency over its entire service life. Integrally installed four 3-way valves maintain the correct flow rate at all times, activating defrost mode if there is a danger of the outdoor unit freezing.
Is it simple to install?
With the Vitocal 150-A and 151-A models, the buffer tank, expansion vessel, and overflow valve – components which usually have to be installed and connected separately – are integrated in the indoor unit. Not only does this reduce complexity and installation time, it means they take up 60% less space in the home than comparable heat pumps on the market.
Does it have a smart, user-friendly control system?
If customers can control their heating easily, reliably and quickly, they will be more comfortable, feel more satisfied and consume less energy.
The Vitocal heat pumps have integrated 7” colour touchscreen displays and WiFi inside offering remote monitoring and fault diagnostics. Furthermore, all Viessmann products are networked within the company’s One Base software platform. This seamlessly connects the new heat pump with other system components such as PV and energy storage, as well as Viessmann’s ViCare customer app and its installer service tool, ViGuide. That means you can keep a remote eye on the system and correct any irregularities immediately without the need to visit the customer.
Flexibility for installers
Providing installers with maximum flexibility is a key concern for Viessmann. It offers a wide range of products for every type of property and is renowned for providing exceptional reliability, thanks to its high-quality German engineering.
It recently added three new, lower output variants to the Vitocal 150-A/151-A domestic air source heat pump range. The 4, 6 and 8 kW models complement the existing 10, 13 and 16 kW heat pumps launched in 2022, making Viessmann heat pumps the best choice for a broader range of properties.
All Vitocal models offer both heating and cooling and the option to be connected to single-phase electricity supply, with three phase models also available for the 10-16 kW variants.
Get £250 for your first install – find out more here
Become a Viessmann Partner
By signing up to be a Viessmann Heat Pump Partner using a simple online form, you’ll get access to a stack of very useful resources and perks, including:
- Viessmann’s partner and installer portals
- a full range of training courses
- the VPlus Loyalty Scheme enabling you to earn points towards an array of items from tools and workwear to iPads and game consoles
- the ViGuide central control and remote monitoring tool for all your installations, showing consumption details and flagging up any errors
- free submission to Gas Safe for your gas boiler registrations.
Signing up could not be easier. Simply complete the online form: https://viessmanninstallerportal.co.uk/register/viessmann