Many commercial buildings have offices or boardrooms that have been renovated over the years and often the mechanical heating or cooling systems have not been fully considered in the change. Walls get moved but the hot water radiators on the floor and air conditioning diffusers on the ceiling stay in the original location. This leads to common problems such as the newly added office on the south wall overheating in the summer because there is no ductwork in the room.
What they are and when to use them
Why condensing boilers?
The natural gas burned in your buildings contains a small amount of water vapor. This water vapor absorbs heat during combustion and carries that same heat up the chimney into the atmosphere. To re-absorb that heat, the flue gases must be cooled enough to condense back to water and release the heat inside the boiler before entering the chimney. All boilers are designed to burn fuel, then absorb the heat from combustion.
Where does it come from?
When an empty system is refilled, all the air in the pipes is compressed and pushed into the highest points in the piping system. With cast iron radiators, that often means the top of every single cast iron rad. The fresh water filling the system also contains up to 10% dissolved air. This explains why after the system is filled and bled, a few radiators have air in them again the next day.
“Hot air rises and warm air rises slower”
Function and fixes
The majority of 4-storey wood frame apartments have copper tube baseboard radiators for heating. This month I will explain how they work and simple things to watch to help reduce complaints and service calls.
Carbon monoxide is a by-product of incomplete combustion and all oil and gas burning equipment has the potential to create carbon monoxide. Carbon monoxide is an odourless, tasteless invisible gas that is only slightly lighter than air so it will rise in a calm atmosphere. It is however easily mixed with any moving air which makes it move easily throughout a building. Because of its nature, this lighter than air gas can be found at floor level depending on air-flow.
Most people are aware that stop-and-go driving in town consumes more fuel than smooth steady changes in speed on the highway. The best option on a long journey is cruise control.
The same principles of cruise control apply to the heating systems in buildings. Boilers starting and stopping with old mechanical limits burn more fuel than a system operated with temperature-sensitive digital controls.
Apartment owners face five significant issues when it comes to heating their properties…
1. Rising Fuel Costs – Heating fuel costs continue to rise, and remain one of the largest continuous expenses in a building. You can raise rent at the rate of inflation plus 2% per year, but that doesn’t cover it. Carefully controlling fuel use is an effective way to close the gap.
There is a trend in increased use of domestic hot water in apartments. As younger tenants move in, more showers and laundry are the rule. These increased loads directly increase the buildings fuel consumption and the result is increased expense.
Understanding how the domestic systems operate will help you address this rising use. In this newsletter, I will focus on the domestic water re-circulation line.