How to specify a water heating option that works for your site.
Water heaters have evolved dramatically in terms of technology, energy efficiency and cost, so it can be overwhelming when it comes to choosing the right water heater for your glampsite or holiday park. So, what are the water heating options?
Storage water tanks
This system stores water in a tank, heated to a pre-determined temperature and held until it is used. The size of the tank decides how much water it can hold. The stored hot water is forced through a pipe at the top of the tank and delivered to where it is required.
While storage tanks powered by natural gas are three to four times cheaper to run than those that use electricity, constantly heating and storing water in a tank ‘just in case’ demand increases will result in much higher energy costs than if you use tankless/instantaneous gas water heaters.
Tankless water heaters
Also known as ‘instantaneous water heaters’, these only supply hot water on demand as and when needed. As they don’t require a tank to store hot water, they don’t produce the standby energy losses associated with storage water heaters, which will reduce energy costs significantly.
While an instantaneous water heating appliance itself can be more expensive to purchase they more than compensate for the upfront costs by maximising the efficiency of the system and reducing running costs.
There are two types of instantaneous gas water heaters – non-condensing and condensing. Condensing heaters are more efficient than non-condensing appliances but either option will be more efficient and cost-effective than an electric appliance. As a by-product of the gas, water heaters produce steam which cools and condenses on a surface. This condensation is acidic and will corrode many materials. A non-condensing appliance will vent the steam directly, whereas a condensing appliance will recycle the extra heat generated from exhaust gases to increase efficiencies. As stated above, while condensing water heaters are expensive upfront, these costs more than balance out with long-term savings on the energy used.
A heat pump can be used as a stand-alone water heating system, or as combination water heating and warm air system. This is an energy saver choice as it uses the heat of the air and the ground to heat the water, instead of electricity.
Heat pumps effectively work like a refrigerator in reverse, moving the heat from one place to another instead of generating heat directly. Heat pump water heating systems are more expensive to buy than conventional storage water heaters but, as with instantaneous water heaters, they have lower operating costs. Heat pump water heaters will not operate efficiently in a cold area as they will cool the area they are in, so their efficiency is dependent on them being installed in an area with excess heat, such as a boiler room.
Solar powered systems
These systems harness the energy from the sun to heat water for storage in a cylinder, and while they can be designed to supply some heating as well, most solar hot water systems are just designed to supply your hot water needs. While solar powered systems are ideal for energy conservation, they are dependent on the weather, so as the available solar energy varies throughout the year in the UK, they may also require the installation of a conventional water heater to top up the shortfall.
Recommended hot water solution
Taking all factors into account, the current recommended choice of water heater for glamping sites and caravan parks would be tankless/instantaneous gas water heaters as they offer the following benefits:
• Instant hot water on demand
• Hot water at a safe, pre-determined temperature
• Endless supply
• Reduced running costs
• High efficiencies
• Hydrogen-blend ready, supporting the UK’s de-carbonisation strategy.
Ventilation of gas appliances
While water heater technology has changed in recent years, combustion water heaters remain the most common and will burn fuel, whether it is natural gas or propane, which releases by-products such as carbon monoxide. Internally mounted instantaneous gas water heaters will need to be vented to the outside atmosphere to avoid exposure to noxious gases created by the combustion process.
Externally mounted water heaters are also available which are installed on an outside wall, so the combustion gases are released directly into the atmosphere. There is no requirement for flues to be fitted on externally mounted models.
As externally mounted water heaters will be exposed to outside temperatures, they are fitted with a frost protection feature that includes electric heating elements. So as long as the water heater is connected to the electric power supply, it will be protected down to temperatures as cold as -4°F (-20°C).
If the water heater is not to be used for some time, such as out of season, and the power has been either switched off purposely, or there has been a power failure, the water heater will need to be drained of all water to prevent damage at temperatures below freezing.
Sizing your system
It is vital that the initial system sizing is correct by calculating peak hour demand for hot water which will ensure the correct water heater is specified to meet even the busiest time at your site.
If you underestimate how much hot water you need to meet demand, you risk running out and upsetting guests. An undersized system is also likely to be overworked and may need repair or replacement earlier. Conversely, if you overestimate the capacity required to meet demand, your initial outlay will be higher as well as your ongoing energy costs.
It may be best to seek advice from a Gas Safe Registered engineer as to the specific output you require to meet the demands of your site, so that you can then decide which system will best suit your demand.
Where more than one appliance is required to meet the demands of your shower block or kitchen facilities, modular hot water solutions guarantee considerable cost savings over other forms of hot water generation. The relatively compact footprint of these systems means they can optimise plant room space and safeguard accessibility for maintenance and servicing.
The systems we supply at Factory Heaters incorporate two or three water heaters, with flues for internal models, to be mounted in a pre-fabricated cascade frame fitted with cable trays, pipe work and electrical connections – providing a complete turnkey solution. All that is needed are the final connections to the associated services, so downtime is reduced dramatically. Where plant room space is limited, externally mounted versions are available which can even be mounted on a suitable roof space.
These modular systems have been developed to guarantee the maximum amount of affordable, ecologically friendly, safe temperature controlled hot water required at any one time by even the most demanding site.
Natural gas or LPG?
With energy prices increasing at the moment, gas is still a significantly cheaper option than electricity. To buy one unit of natural gas (measured in kWh) will currently cost around 7p/kWh, whereas one unit of electricity from the mains (also measured in kWh) will cost around 31p/kWh.
If your site is connected to the natural gas network, this has many advantages over LPG (liquefied petroleum gas) including much higher efficiency, cleaner burning and greater affordability. If however your site is not connected, you can still utilise gas rather than a more expensive electric option as instantaneous water heaters can be available to support an LPG supply. This would then require either an LPG storage tank or LPG gas bottles to be available which can be piped to the appliances.
For off-grid sites, LPG has a number of advantages over other energy sources such as oil, coal or electric heating systems. For example, while LPG usually costs more than heating oil, it offers a much greater energy return due to its high efficiency, with reduced costs in the long term. LPG also produces a lot less carbon when burnt, helping towards a cleaner environment.
Gas Safe Registered installation
Having sized your appliance correctly and made your gas water heater purchase, you have a legal obligation to have your appliances installed by a Gas Safe Registered engineer, so that the installation is in accordance with manufacturer’s recommendations, as well as in compliance of current legislation. Failure to comply with these requirements is both illegal and potentially dangerous and will also invalidate any warranty.
Installations will also need an annual Gas Safety Certification to maintain the integrity of the manufacturer’s warranty
The UK government has set a target of net zero carbon emissions by 2050 and it’s likely that hydrogen will play a major part in this strategy. Green hydrogen is the ultimate aim as this will be produced from renewable energy sources and produce the least CO2 emissions. However, it will be necessary to transition towards green energy utilising current technologies and it is likely that hydrogen-blend appliances will form a major part of this transition.
Hydrogen-blend appliances will support a blend of 20% hydrogen with 80% natural gas. This will make use of the existing network to deliver greener gases, keeping customers warm and with a constant supply of hot water, while still being able to enjoy the flexibility of gas.
Which water heater?
For a small pod, a 17L instantaneous water heater has proven to be popular. The external model in particular will save space as it can be fitted on the external wall of the pod. Available in LPG, off-grid sites have taken advantage of this water heater to meet all the hot water demands of smaller pods.
For larger structures, or to feed shower blocks and kitchen facilities, a 26L or 32L instantaneous gas water heater will be more suitable. They can be installed within the block or external versions can be mounted on an external wall or suitable roof space.
Where more than one water heater is required, a modular solution will guarantee considerable cost savings over other forms of hot water generation. The relatively compact footprint of our systems can optimise plant room space and safeguard accessibility for maintenance and servicing.
About the Author
With more than 25 years’ experience installing hot water systems in the hospitality sector, Winrow Building Services’ developed Factory Heaters is an online store offering high-efficiency and cost-effective hydrogen-blend water heaters to ensure caravan parks and glamping sites are future-proofed to support the government’s transitional hydrogen strategy.
For further advice or to make use Factory Heaters’ installation service, get in touch with the team at www.factoryheaters.co.uk