How to select a heat pump for your house, a step by step guide designed for heat pump beginners.

In the current heat pump boom we are getting lots of people interested in getting into the heat pump industry, like it or loathe it this is exactly what we need if we are going to make heat pumps mainstream. We get asked what info we need to help select a unit and are constantly asked for guidance, so this little guide should help. Enjoy. and feel free to share or plagiarise if you want to.

Like all suppliers we offer training courses for our customers and cover all this in detail, but I thought this week I would give you a whirlwind tour of how to do it. Here goes.

A heat pump is a direct replacement for any boiler, its our job as a wholesaler to guide you to the unit which is going to help fit your house or project best.

 Step 1: Establish why the homeowner wants a heat pumps, is it to be green or is it all about saving money? In many cases i.e. houses on mains gas its highly unlikely that they are going to save lots of money, heat pumps are expensive to install but the government grant called RHI was designed to help make the costs even between gas and a heat pump.

 Step 2:Establish some budget figures. Does the homeowner know how much a heat pump is going to cost to install? In a normal size 100-250 m^2 house a boiler typically costs ￡3000 -￡4000 to install but a heat pump is normally 3 times that figure. Unless you have an enormous house or you are a heat pump denier it should not be anywhere near ￡20000.

 Its really important to get these 2 points over early in the discussion, there is no point spending hours designing and measuring up for a heat pump if the customer cannot or will not spend the money.

 Step 3: Carry out an over the phone or virtual survey / info gathering exercise. You need to put together a budget including Carbon saving, run cost saving, grant value and return on investment(how long it takes to pay back).To do this we have a simple tool  Is a heat pump right for me?  https://form.jotformeu.com/200683492235354  

This tool will give you the current predicted cost of your heating and new cost with a heat pump. The amount of carbon you will save by shifting to a heat pump. A guide to the grant that the homeowner can expect to receive.

 We recommend you use this tool before going to site to see If the numbers work for the customer. If everyone is happy lets go to the site visit.

 Step 4:The Energy performance certificate. To get the government grant you have to have an energy performance certificate done, it has to be under 2 years old. It costs about ￡50 to do. What they are looking for is the insulation in the house, they have to check for is whether the house has cavity wall insulation and loft insulation 200mm thick. If not these have to be done before the heat pump is installed it’s a condition of the government grant, they wont pay if you don’t do at least the minimum to insulate your house.

Step 5: The onsite survey. MCS is the scheme which is used to get the government grant and to make sure you are providing the correct heat pump. MCS demands a full room by room heat loss is completed, this means you need to measure and draw out a plan of every room in the house, you must include every radiator and window. You need to find out what the floors, the roof, the walls and the windows are made of.

Ideally draw us a plan like this with all the rads on it. You also need to get a photo of the electricity meter MPAN number there is a number on it called the MPAN number you need this. While you are at it get a photo of the electricity distribution board, the sparkys will need to see this.  

Step 6 Sighting the unit. It’s a good idea to also look to see where the heat pump is going to go. Think of a few points:

·       Keep it as far from the neighbours as possible to avoid noise complaints, plan to keep it 5m or more from the neighbour’s house

·       The unit produces huge amount of very cold air, it wants to blow out into a large area, don’t put it in a tight space, it wont work, if in doubt draw a sketch and get photos.

·       If the unit is going down the garden how are you going to get the pipes to it? the further it is from the house the more expensive its going to be, typically its ￡100 a metre from the house

·       The heat pump wants to be a maximum of 15 metres from the new hot water cylinder, its possible to go further but you must make a not of this, we need to know when we are speccing the kit.

·       You are going to have to put a new hot water cylinder in, heat pumps are not capable of making instant hot water a cylinder is normally 600mm diameter and 2000mm high

 Step 7: Ask the customer if they want to keep the old radiators or are they happy to have some new ones fitted?

 Heat pumps work best if we can run them at 50 degrees C, this is lower temperature than a boiler (typically 70C) so the radiators shrink in size. Its highly likely that many of the rads will need upgrading, but if the customer is attached to the rads in the house there are special heat pumps which will run at 70C but be carful these are expensive to buy and more expensive to run. We need to know this before we do the system design.

 Step 8: Send the info to us so we can do the MCS maths for you and select the best unit. Once you have all the info, someone needs to do a heat loss and select a heat pump which is big enough to do the job, most of our customers ask us to do this but you can also do it using our heat load calculator tool.  ask for a copy we will send it to you.

The heat loss: The most important part of any heat pump installation is making sure that the correct size heat pump is installed in the house. If the unit is too big then the system will be too expensive compared to the price of a new boiler. This may lead you to lose the order if a competitor has offered a lower price. However, if the unit is sized small, on the coldest days in winter the heat pump will not be able to provide enough heating and hot water to keep the house and water at the desired temperature. There are many variables that need to be considered when sizing a unit e.g. U values, volume of water needed, the coldest temperatures possible. Sizing using rough guides is a sure-fire way to run into problems, it needs to be done properly. If you want our heat loss tool let us know we will send it to you.

Step 9: The system selection and design. Once we input your data into our tool it will select you a heat pump and a cylinder. It also checks the radiators are big enough for the job and recommend new ones where required.

Our team will send you selection with a graph showing how the unit will cope with the load, a carbon saving, run cost comparisons, the value of the grant and a monthly breakdown of what the unit will cost to run.

They will also send you an information sheet on the unit we recommend, a system schematic showing what will arrive and how it goes together including the wiring

 Step 10: Your quote

Once we have quoted you a system and you are happy with it you need to send the info with your quote to your customer and your installation costs so they can decide if this is the system they want to buy.

I will cover the MCS and grant application on another blog in the next few weeks.