A hotel, a hospital and a residential campus have the same problem. They need hot water all day, in large volumes, at moderate temperatures. Most of them still make it with electric geysers, diesel or a small boiler.

A commercial heat pump makes the same hot water from much less energy. We set out where it fits, what it replaces, and how to size it.

What hot water does a building like this need?

The loads are moderate in temperature. That is what makes them a good fit.

All four sit well inside what a commercial heat pump delivers. None of them needs steam.

What does it replace, and what does it save?

The saving depends on what makes the hot water today. Here is the cost of one useful kilowatt hour of heat at 2026 prices:

The comparison against electric geysers matters most for many buildings. A geyser turns one unit of electricity into slightly less than one unit of heat. A heat pump at COP 3.5 turns the same unit into three and a half. On the same tariff, the heat costs about a quarter as much.

A building that runs on coal or briquette is different. Delivered coal costs about ₹1.94 a useful kilowatt hour, which a heat pump on grid power does not beat. There, the case is air quality, compliance and labour.

Why the morning peak decides the size

Hot water demand in a hotel or hostel is not flat. It peaks in the morning, when guests or residents shower at the same hour. A second, smaller peak comes in the evening.

A heat pump works best running steadily. So the usual design pairs a smaller machine with an insulated storage tank. The machine runs through the night and the quiet hours, and the tank covers the peak.

Sizing a heat pump to the peak alone gives a large machine that sits idle most of the day. Sizing it to the daily total, with storage, gives a smaller machine that runs longer. The second is usually the cheaper project.

Does a hospital differ from a hotel?

The loads are similar: wards, kitchens and laundry. Two things change.

The first is continuity. A hospital cannot run out of hot water, so the design needs a backup, often the existing heater. The second is hygiene. Stored hot water must be held hot enough, and long enough, to keep it safe. Tell the supplier the hospital's own water safety rules before they size anything.

What about a campus or hostel block?

A campus is a set of smaller buildings with one pattern of use. Hostels peak in the morning, like a hotel. Kitchens and laundries run through the day.

One central plant with a ring main can serve several blocks. Separate machines per block avoid long pipe runs and their heat losses. The choice depends on the distances, so put a site plan in front of the supplier.

What to ask before you buy

• The output temperature at your duty, not the machine's maximum.

• The COP at that temperature, with the air or water temperature it was measured at.

• The storage volume it assumes, and the peak it is sized for.

• The backup plan when the machine is down for service.

• The electrical load it adds to the building.

• Who services it, and how fast they respond.

Hotels and hospitals that make hot water from diesel or electric geysers gain the most from commercial heat pumps. Makers such as Tetra Heat Pump, an Indian maker, build air source and water source machines for this range.