CASE STUDY: Barn to Boiler Room

Barn to Boiler Room

A three bedroom cottage with two bathrooms has a remote boiler room connected to the house by a heat main. This supplies two radiator circuits and a mains pressure cylinder for domestic hot water.

The boiler is a Baxi solo Innova 30 which burns logs from the owner’s woodland. One charge per day heats a 1500 litre thermostore cylinder from which are drawn the heating needs of the cottage. This cylinder is also heated by solar panels installed later as a second phase. These are able to take the place of the boiler and also generate enough to meet the needs of the cottage. 

Where the heating flow is drawn from the top of the cylinder, a thermostatic valve governs the temperature of the water. This provision ensures the safety of the household and preserves the temperature within the thermostore.

In the cottage, programmable thermostats maintain separate temperatures for upstairs and downstairs by opening motorised valves which in turn start the pump to draw heat from the thermostore in the boiler room. Thus, in this installation, the solar panels provide heating for both domestic hot water and two radiator circuits.

PROS:

-          Solar panels preheat the thermostore and reduce batch burn time

-          During the summer the solar panels create more than enough hot water

CONS:

-          Labour intensive during the winter months

-          Needs a lot of space to store logs, house equipment

-          Needs a south facing roof

-          No automation

GOOD FOR:

Rural, detached medium sized house with outside storage.

For more information on this case study or others, please call us on 01579 345018 or email sales@stoveshop.co.uk 

CASE STUDY: Detached House with Detached Boiler Room

Detached House with a Detached Boiler Room

A Baxi multiheat 2.5 (25 kW output) wood pellet boiler, installed in an external boiler house, provides central heating and mains pressure domestic hot water to a four bedroom house with three bathrooms. There is also a thirty tube solar array which significantly contributes to both the domestic hot water and central heating.

At the heart of the system is a three hundred litre thermostore cylinder which is heated directly by the boiler and indirectly by the solar through a coil at the bottom of the cylinder. 

The domestic hot water is exchanged at the top of the cylinder and passes through a blend valve to control the temperature of delivery. 

Central heating is drawn from the middle of the cylinder and uses the system water directly to the radiator circuit and a in an auxiliary mains pressure cylinder for the bathrooms. The upstairs and downstairs radiator circuits are controlled by wireless programmable thermostats.

PROS:

-          Utilises garden shed

-          Semi automatic pellet burning boiler

-          Reduced fuel costs by 60% compared with oil

-          Solar input also reduced pellet costs

CONS:

-          No pellet store close to boiler, thus labour intensive

-          Need a large, dry area to store pellets

GOOD FOR:

-          Detached town house with large garden

FoFor more information on this case study or others, please call us on 01579 345018 or email sales@stoveshop.co.uk 

CASE STUDY: Farmhouse with Boiler Room

Case study; Farmhouse with Boiler Room

In a remote boiler room a Baxi Multi Heat 2.5 600f boiler produces hot water for the farmhouse. At present the fuel is wood pellets but the boiler can be adapted to burn wood chips or even grain. A 23 metre underground submain of insulated pipes connects the boiler room to the main house. Then the hot water is delivered to a 300 litre heat store cylinder containing a high efficiency heat exchange coil which delivers main pressure domestic hot water to the bathrooms and kitchen. 

The cylinder also supplies a distribution system for three separate radiator circuits; upstairs radiators, downstairs radiators, towel rails and airing cupboard. These three circuits are separately timed to allow complete control. The cylinder has a 3kW immersion heater fitted for optional use in summer. The cylinder also has a coil to accept input from the solar panels on the roof and the control box has a contactor to isolate the immersion heater if the cylinder temperature rises above the set point of 90 degrees. Similarly, if the cylinder is below the set point of 40 degrees, the radiator circuits are isolated to allow temperature recovery.

The system has been cleansed, flushed and protected with Fernox F1 and filled to a standard ½ bar pressure and sealed. The heat expansion is absorbed by an 80 litre expansion vessel in the boiler room. There is a temperature and pressure relief valve on the cylinder and a pressure relief valve in the boiler room.

PROS:

-          Pellet prices are low; the entire central heating system is run on the equivalent of 35p of all; essentially, making a saving of 60%

-          Automatically fed boiler, not labour intensive. During winter the 35 litre lopper is filled every two days, and the ashpan emptied every two weeks. This reduces to once a week/every three weeks respectively in the summer months.

-          Carbon neutral

CONS:

-          Physical size of boiler 1200mm x 1500mm x 600mm

-          Additional cost of chimney if not already in place

GOOD FOR:

-          Rural situations with lots of space for equipment and storage of pellets.

-          Large houses

-          Unsuitable for two bed city dwellings.

FoFor more information on this case study or others, please call us on 01579 345018 or email sales@stoveshop.co.uk 

CASE STUDY: Solar Collector and Underfloor Heating

Case Study – Boscastle Cottage

There is a 16kW Fireview woodstove in the living room with an integral boiler which heats a 300 litre thermostore directly. This thermostore has a high efficiency coil to provide mains pressure hot water at 35 litres per minute.

Also in this thermostore is a coil for the solar collector which heats the cylinder directly as does the woodstove. It follows that either of these heat sources will provide domestic hot water and the solar  will contribute to the central heating even at times meeting the demand. A control panel on the upstairs landing displays the current activity and records the solar gain and kW hours.

Additional features of the cylinder are: a stratification plate positioned below the DHW coil which ensures a higher temperature at the top of the cylinder for hot water priority , a blend valve to govern the temperature of the DHW and two independently switched immersion heaters for backup if required.

The two zones of underfloor heating are controlled by Honeywell programmable room thermostats.

The upstairs radiator circuit has a Honeywell wireless electronic thermostat coupled to a twin channel timer, the second channel of which controls the towel rails.

PROS:

-          Underfloor heating has a large surface area so little energy is needed to power it.

-          All future installations of this nature are eligible for Renewable Heat Incentive

CONS:

-          Thermostores are large and heavy ; a reasonably secure first- floor space is needed

-          Thermostore has to be open vented due to solid fuel

-          Reliant upon the weather

GOOD FOR:

-          Second homes, as the underfloor heating automatically airs the house when no-one is there

-          New builds or renovations ; this system would easily allow a building to reach Code 3.

FoFor more information on this case study or others, please call us on 01579 345018 or email sales@stoveshop.co.uk