Are you managing apartment blocks fitted with communal heating systems?

The measures Ofgem have introduced to protect consumers from rising energy prices show how important they think it is to protect us from this volatile energy market. But there is a flaw to this price cap in that it does not cover heat networks, so if you have an apartment block with a communal heat network or a building fed by a district heating network your residents are not protected and will be subject to commercial fluctuating pricing.

The implication of this is that the price of gas consumed to heat communal networks is likely to be well in excess of the OFGEM price cap, thus penalising residents. So with this in mind, what can you do to help protect your residents from a significant increase in the cost
of heating their homes and generating hot water, preventing fuel poverty and providing an unnecessary struggle to pay their bills?

The first thing to look at is the cost of gas and electricity being charged to run the communal system and to look for more competitive offers.

Equally important is the efficiency of the heat network. If the boiler, or other equipment in the plant room, is running inefficiently or the distribution heat losses in the primary pipe network are high, this will directly affect the tariff being charged to residents.

Gas Boiler Network table illustrates how the efficiency of the boiler and losses from the distribution network affect the cost of running it, with the resulting heat unit rate (tariff) which the resident ends up paying for their heat. All three networks above are delivering 1,000,000 kWh of heat to the residents, but Network 3 would use 2,507,402 kWh worth of gas to do this, whilst Network 1 only uses 1,384,000 kWh worth of gas.

Network 1 is an example of a relatively good communal heating system where the boiler is running at an 85% efficiency with 15% heat losses from the distribution pipework. The gas consumed equates to £55,363.32 which is the sum used to calculate the unit rate for the residents, so this cost is divided by 1,000,000 kWh giving us a unit rate of 6 pence per kWh.

Network 3 is an example of a poorly performing heat network, however not
an unusual example. For this network, the total cost of the gas is £103,896.10, giving us an equivalent unit rate of 10 pence per kWh, a 66% increase in the rate!

You can easily check the efficiency of your communal heating system by getting the gas bill (or electricity bill if the system is fed by a heat pump) for a set period, look at the kWh consumed by the boiler and compare this figure to the accumulative kWh delivered to all residents over the same time-period.

This enables you to see the total efficiency of the network, i.e. how much of the energy consumed by the boiler gets delivered to the consumers?

If you have a bulk meter attached to the primary pipework in the plant room, you can also see the amount of heated water which is sent into the system from the plant room. From this you will be able to break down these energy losses by boiler efficiency losses and distribution heat losses.

Once you have analysed the efficiency, and hopefully been able to break it down, there are a number of ways to improve performance and efficiency, some of which are relatively inexpensive.