Calorifier Sizing

What is a Calorifier?

A calorifier is a commercial grade indirect hot water cylinder which is designed to meet the performance requirements of a commercial property from offices to hotels and from leisure facilities to factory units. Calorifiers tend to be manufactured from copper to reduce the risk of legionella with suitalby sized back up immersions to ensure the hot water demands are met. We tend to recommend de-stratification pumps to allow the water to be continually circulated to avoid pockets of cold water forming and an inspection manhole to provide easy access should the need arise.

How to Size a Calorifier

When it comes to Calorifier Sizing, it is important to determine not only the correct size but also the correct relationship between storage and recovery to enable the most efficient usage from your hot water system. Oversizing the calorifier can lead to unnecessary costs both in your calorifier cost and in the ongoing running of your system. On the other hand inadequate storage can lead to the system not meeting the users requirements. For most commercial situations a storage capacity sufficient for 1 Hour output with a corresponding heater input is considered adequate. However, a pattern of hot water usage can be projected based on the function of building, the activity that takes place and its population. For example, environments such as Offices and Schools usually operate on a 12 hour period and other buildings such as Hospitals and Factories may operate on 24 hour periods. Where the shower demand takes up the majority of the hourly consumption, efforts should be made to obtain an accurate estimate of the total usage and the timespan involved. Where installation space permits, additional storage volume can provide a useful reserve of hot water. If space for 1 Hour storage volume is not available then increasing the power output of the heat source could allow for the storage capacity to be reduced accordingly. For recoveries below 30 minutes, McDonald Water Storage PLATEflow, a combined buffer and plate heat exchanger system should be considered. Additionally, dividing the total storage demand between multiple Calorifiers can also safeguard the supply and would also allow part of the system to be shut down during off peak periods or seasons, this can be particularly helpful for Hotels with seasonal demand or Sports Centres where high demand can be predicted a certain times of the day or week.

Calorifier Sizing Guide

The sizes below provide a general guide to the approximate sizes of calorifiers for key capacities, however we can design and manufacture a calorifier to your exact requirements. To find out more about our full range of calorifiers click here or contact our technical sales team on 01592 611123 to discuss your project.

Calorifier Sizing – Capacity vs Standard Shell Sizes

Capacity (litres) Shell Size (mm)
450 1800 x 600
500 2000 x 600
550 2200 x 600
600 1800 x 675
700 2150 x 675
700 1700 x 750
800 1950 x 750
900 2200 x 750
1000 2200 x 800
1000 1750 x 900
1200 2050 x 900
1500 2500 x 900
1500 2000 x 1050
1800 2400 x 1050
1800 1750 x 1200
2000 2500 x 1050
2000 1950 x 1200
2500 2450 x 1200
2500 1900 x 1350
3000 2900 x 1200
3000 2300 x 1350
3500 2700 x 1350
4000 3050 x 1350