Frequesntly asked Questions
Providing Renewable Green Energy Solutions to Pembrokeshire, Carmarthenshire, Ceredigion and the Swansea Area.  As yours works by hovering cursor over your picture

Call: 01437 765888

For a free no obligation quote please call enquiries on 01437 765888


Just a quick note to say the biggest Thank You possible for all your hard.


Frequently Asked Questions

  1. Solar
  2. Geothermal Ground, Air, Exhaust and Waste Source Heat Pumps
  3. Under floor Heating
  4. Biomass wood, pellet and chip boilers


What is Solar Water Heating?

Solar Water Heating is a system for heating water using solar radiation. Solar energy is collected by a panel or panels depending on the requirement. These are usually installed on a roof though they can be mounted onto a frame for flat roof or ground installations. The panel or panels are then connected by pipes to a hot water store device such as a hot water cylinder.

Do they work effectively in the UK?

Yes, they can work very effectively in our climate even on overcast days as the collectors absorb energy from diffused as well as direct sunlight. The Solar Water Heating solutions that we offer are capable of providing all of your hot water needs for up to 8 months of the year.

Do I need planning permission?

No, in most cases. However it is advisable to inform your local authority of your intention to install a solar system and obtain approval. We will always assist you with this process if required.

How much will it save on my Utility bills?

You could expect to save between 50% - 70% of your annual water heating costs.

Will it help reduce global climate change?

Yes, reduces your CO² emissions by as much as 2000 cubic meters per year.

What type of solar collectors do you supply?

Green Warmth, supply both Evacuated (Vacuum) and Flat Plate collectors depending on the installation requirement.

Evacuated Tube collectors use an evacuated glass tube to enclose each pipe and its associated absorber plate. They can provide up to 70% of the household’s domestic requirement per annum. Convection losses are almost elimated by the vacuum in the tube, they are unaffected by factors such as wind chill or ambient air temperatures which allows them to absorb whatever solar energy is available, even on cold/dull days. This enables this type of collector to provide hot water for up to 8 months of the year and assist your water heating during the winter months.

Flat Plate collectors use an absorber plate with a specially developed black coating to maximize the collection of solar energy whilst simultaneously limiting re-radiation of energy back to the atmosphere. These collectors can provide between 50 – 70% of a household’s domestic hot water requirement per annum.

Do I need a new hot water cylinder?

In most cases yes, a new twin coil or thermal store tank would be required to provide the most efficient system. A solar coil can be fitted to an exiting tank but these are a lot smaller than the ones provided as part of a tank and therefore not nearly as effective.

Are the solar systems you install covered by a warranty?

Yes, the “Evacuated Solar Collector” tubes are guaranteed against manufacturing defects for five years and provide a components and labour guarantee of 1 year from the date of installation.

The “Flat Plate Solar System” has a components guarantee of 5 years and a labour guarantee of 1 year from the date of installation.

What after sales service do you provide?

It is important to us that our customers are completely happy with their installation. We will phone you two week after the final commissioning date to establish whether you have any questions or queries with the system and address these with you. A year after installation we will send you a reminder to complete a basic routine maintenance task on your system. After 5 years, we will contact you to advice that some maintenance tasks need to be completed on your system as detailed in your Solar manual. These should really be completed by a solar specialist and we will complete these on your behalf, if you require for a nominal fee.

How do I obtain a quotation for a solar solution?

To enable us to provide you with a quotation, we need to obtain some information about your home/building and hot water requirement to ensure we are providing the correct solution for your needs. Please complete the questionnaire under our quotation page for Solar Heating.

Geothermal Ground, Air, Exhaust and Waste Source Heat Pumps

How does a heat pump work?

A heat pump works on the same principle as a fridge but in reverse. A fridge uses a refrigerant to extract heat from the inside of your fridge, which it then expels to keep the contents of the fridge cool. By using the same process, heat pumps take heat from an ambient heat source or waste energy to heat your water. Ambient heat can be obtained from water, air, ground and waste or exhaust energy from the home or industrial processes.

How does it collect the heat?

The earth, water and air have the ability to absorb and store heat from the sun, a heat pump takes this renewable energy store and transfers it into your building. For example, in the case of a ground source system the heat is extracted from the earth using a ground loop. The ground loop is a continuous closed loop of special pipe buried in land around the building. A mixture of water and food grade anti-freeze is circulated through the buried pipes where it absorbs heat from the surrounding earth. The ground loop is connected to a heat pump inside your building that takes heat out of the circulating mixture and transfers it into your heating circuit and hot water tank.

How energy efficient is a heat pump?

Heat Pump Systems can be over six times as energy efficient as the most efficient gas or oil boiler. Instead of burning a fuel and producing the associated emissions they simply move energy that already exists, stored solar energy. On average for every unit of electricity used 4 units of heat are produced depending on the product you use. This equates to 75% of your energy coming from your own renewable energy source and the other 25% comes from the electricity used

Where should a heat pump be located?

Either in a utility room, garage or housing outside.

Do they make much noise?

No, they sound very similar to the hum of a fridge

Will it heat my house even on the coldest days?

Yes it will. Heat pumps have been used in Scandinavia for many years where winters are a lot harder than the UK. Heat pumps can extract heat from the ground to minus 10 degrees.

Can a ground source heat pump work with existing radiators or do I need underfloor heating?

Both Ground Source and Air source heat pumps can be linked into existing heating and hot water systems. However they work much more effectively with underfloor heating as the low input temperature required by the under floor heating system can be closely matched by the output temperatures from the pump.

How do I obtain a quotation for a heat pump?

To enable us to provide you with a quotation, we require information about your building project to ensure we are providing the correct solution for your needs. Please complete the questionnaire under our quotation page for Ground, Air, Exhaust and Waste heat pumps.

Under Floor Heating

What is underfloor heating?

Under floor heating is created by circulating warm water, through a series of pipes laid in the floor at the time of construction. These pipes are of the highest standard and form a continuous loop between wall mounted central manifolds. Each room has its own circuit which is controlled by a thermostat that enables you to control the exact heat requirement for every room.

Where Can underfloor heating be used?

In almost any building and with almost any form of floor construction, whether in a new-build or refurbishment.

Why is Underfloor Heating not more widely used?

As with renewable energy it is widely used in various European countries. In France, it accounts for 40-50% of all heating. In Germany for 50-60% and in Switzerland and Sweden it percentage is even greater.

In the UK, it is around 5-10% but this is rapidly increasing. It is slightly more expensive than conventional radiators but offers much greater comfort and lower running costs.

What fuel is required for underfloor heating?

You can use any fuel to warm the water that circulates through the underfloor heating pipe. They work particularly well with alternative heat sources such as a heat pump, if renewable energy is not an option a condensing boiler, is a suitable alternative. They both work well at low temperatures which is a requirement for underfloor heating.

How do you control underfloor heating?

Underfloor heating is controlled with a room thermostat which uses a motorized valve to turn off the flow of hot water through the pipe when the room is warm. Using the modern programmable room thermostats, the room temperature can be set to different demand levels at different times of the day or week

Are there any restrictions on floor coverings?

Although underfloor heating will work through most floor coverings, some are better than others at transferring heat. We are happy to advice on suitable floor coverings as part of the complete design process.

How do I obtain a quotation for underfloor heating?

To enable us to provide you with a quotation, we need to obtain some information about your building project to ensure we are providing the correct solution for your needs. Please complete the questionnaire under our quotation page for Under Floor Heating

Biomass wood, pellet and chip boilers

What is Biomass?

Biomass is fuel produced from organic materials grown over the last few decades. Biomass comes in many forms but to generate both heat and hot water in buildings the most appropriate fuel is wood. Unlike fossil fuel, wood is a renewable form of energy. When burnt the carbon dioxide (CO²) that is released into the atmosphere is only the CO² that the plant would release when it died and decomposed. In other words, it creates a ‘closed carbon cycle’ where the same amount of CO² is absorbed from the atmosphere by the biomass as is released when it is burnt, making it carbon neutral.

Why invest in a biomass boiler?

Burning wood to provide your space and water heating uses a renewable energy that will not damage the environment. Wood reduces the dependency on imported fossil fuels which stimulates rural economies by producing and using wood fuel locally. Wood fuel is often cheaper than its fossil fuel equivalent, and initial investment in biomass boiler systems can be recovered within 5 – 10 years.

How efficient are Biomass Boilers?

Biomass boilers are very efficient. Using the best of modern technology, biomass boilers can achieve over 90% efficiency – dramatically more than conventional boilers. Sophisticated control systems and burn efficiency mean that heat and fuel are not wasted. There is very little ash, and the small amount that is produced can go straight onto your garden as fertilizer.

What are the types of wood fuel available?

Wood is a very versatile fuel and can be burned in many different forms to provide space and water heating. The most common forms are logs, pellet and chip.

  • Logs

Logs are the most common form of wood fuel available in the UK. They are cheap and locally available but need to be seasoned and split prior to use. Logs however require less processing than wood chip or pellet and provide a high energy density per tonne. Log boilers, when burned at full capacity can have efficiencies of up to 92%.

  • Pellets

Wood pellets in the form of sawdust, recycled pallets or specially grown crops such as willow coppice are dried and processed into easily combustible pellet form. They can be delivered by bag or by a blower truck. Pellets are ideal for automated boilers as they require less attention compared to both log and chip system and are the most convenient wood fuel to use for a domestic setting. Pellets are however more expensive than logs due to the level of processing required.

  • Wood Chip

Wood chips are simply wood that has been chipped to a consistent size. Wood chips can be made from either recycled wood or specially grown crops (e.g.: willow coppice) Wood chips require less processing than wood pellets but have a lower energy density (less energy per tonne). They therefore require much more storage space and a larger fuel handling systems to enable then to run unaided for the same time span as pellets. Wood chips are generally only suitable for larger scale projects but provide a cost effective solution for these providing that the moisture level and chip size are monitored effectively.

Which solution is most suitable for my project?

There are several factors you need to consider before deciding which biomass boiler would be most suitable for your home or business requirement

Considerations for a log Boiler

  • § Do you have a free supply of fuel from your own land?
  • § What level of maintenance are you willing to undertake. The most automated log boiler will need to be lit and refueled on a daily basis during the heating season.
  • § Your project is small and does not require a boiler more than 70 kW.
  • § You have sufficient dry storage for seasoning and splitting logs.

Considerations for a pellet boiler

  • You require a fully automated system than can provide at least 3 days automation with an integral fuel hopper or when connected to a larger store the boiler can be supplied with pellets to provide heating for a complete season.
  • Your project is small to medium (requirement from a 10 -100 kw boiler)
  • You require a compact system and fuel store. Logs and particularly wood chip require much larger storage areas.

Considerations for a wood chip boiler

  • You require a fully automated system which requires virtually no fuel handling.
  • You have a medium to large scale project (requirement from 50 – 1000 kw)
  • Wood chips have a lower energy density than pellet and therefore require much more storage space and a much larger fuel handling system. Wood chip is therefore not considered to be a viable solution for most domestic Installation.
  • You are able to use miscanthus or willow, or have an on-site timber resource.

What Size boiler system do I need?

The boiler capacity depends on the energy efficiency and size of the building. This will be evaluated as part of a site survey.

How much will it cost?

This is too broad to provide a simple answer as it depends on so many factors, which boiler you choose, which feed system you require for the boiler. Each installation is unique and designed to meet your specific requirement.

To provide some guideline please see table below

Property Boiler Rating and fuel type Installed Cost
3-4 bed roomed house 10Kw - 50kw log or pellet boiler From 7000 – 16,000
Large farmhouse/estate 60 kw – 100 kw pellet/woodchip boiler From 20,000
School/public building 150 kw chip boiler From 40,000

How much space will I need?

Space requirement varies depending on the heat output requirement and the fuel type. The system can often be sited in an existing boiler room, basement or small outbuilding.

Do I need planning permission?

You will not require planning permission for the boiler, but you should check with your local authority if you need to fit a new flue or build a boiler house or fuel store. New flues for domestic installations should be installed by a HETAS registered installer.

Are there grants available?

As biomass technology is classed as a low-carbon, renewable energy source there are grants available. Domestic Households can obtain £1,500 towards the cost of a biomass boiler system from the Low Carbon Building Programme phase 1. Public Sector buildings (Schools, Hospitals, Housing Associations and Local Authorities & Charitable Bodies can receive up to 50% towards the cost of a biomass boiler system from the Low Carbon Building Programme Phase 2. Commercial can obtain Financial incentive. Capital grants from the Bio-energy Capital Grant Scheme are looking to re-launch there scheme toward the end of 2008.

How do I obtain a quotation for a biomass boiler?

To enable us to provide you with a quotation, we require information about your building project to ensure we are providing the correct solution for your needs. Please complete the questionnaire under our quotation page for Biomass Boilers or phone Green Warmth on 01437 731393.

Heat Pumps

The earth, water and air have the ability to absorb and store heat from the sun

Heat Pumps

Biomass Boilers

Unlike fossil fuel, wood is a renewable form of energy. When burnt the carbon dioxide (CO²)

Biomass Boilers


Solar Heating is a rapidly growing market in the UK. As solar thermal technology does

Solar

Under Floor Heating

Under floor heating works by pumping controlled flows of warm water from a heat

Under Floor Heating

Heat Recovery

We now provide solutions for Heat Recovery and Comfort Conditioning.

Heat Recovery

Other Services

We can provide solutions for other renewable energy products, depending on the requirement.

Other Services

Green Warmth is the trading name of Green Warmth Limited
(Company Registration Number: 6330027)
Registered Office: The Walled Garden, Wiston, Haverfordwest, Pembrokeshire SA62 4PN