If your business is contemplating a warehouse or a large open-space building, then no doubt one of the challenges facing you is: how are you going to heat such a large space?
The old stand-bys are hanging Modine-type heaters and, to a lesser extent, large cast iron finned piping. The finned piping will help heat the perimeter wall area of the building, but is not really very practical for heating such a large space. The Modine-type heaters have been doing the job for a long time. They are generally trustworthy and easy to work on. They use a variety of methods to produce the heat including steam, hot water, and even oil-fired mini-furnaces right inside the heaters themselves. The problem with these types of heaters is that they have to be hung from the ceiling at a low enough level for the workers and merchandise to get any benefit from the heat. This can be a challenge if you’re looking for an unobstructed high bay.
What Are the Alternatives?
One alternative is radiant heat built into the floor, known as Radiant Floor Heating or (RFH). There are two types of systems available: electric (electric heat coils running through the floor), and hydronic (piping or tubing containing a heated fluid running through the floor). In a large installation like a warehouse, it would not be cost efficient to operate an electric system, so we’ll discuss hydronic systems today.
Your building will have a toasty warm floor, and as we all know, heat rises, so the rest of your building will stay warm as well. You’ll have the challenge of keeping it warm when the bay doors are open, but no more so than with any other type of heat in a building like this.
There is a crane maintenance facility at the military base where I work in New England that uses a hydronic RFH system, and the system works phenomenally. It consists of a boiler heating a forced hot water system. The hot water is circulated through a couple of heat exchangers. The other side of the heat exchangers is filled with glycol (glycol is an anti-freeze substance used in case the system was shut down for any length of time during cold weather periods), that is circulated through tubing running under the floor. The whole system is run electronically by computer, using both sensors in the building and an outside temperature sensor monitored by the computer to tell the system when to come on. If the system should fail, the computer will even tell the maintenance personnel what caused the failure, greatly aiding in the troubleshooting and repair time.
How Is the System Laid Into the Floor?
Usually the tubing is set into the concrete, so the concrete will heat up and hold the heat—much like a pizza stone in the oven, or the warm bricks of a fireplace. There are installations where the piping is run between the floor and a sub floor, but that would be more for residential use than a commercial building.
Are There Any Obstacles?
The biggest obstacles encountered usually stem around training the maintenance crews to use the computer and electronic controls. Most commercial HVAC contractors are versed in these systems, but make sure the one you hire is familiar with the specific control system that you have in place. If you’ve got an on-site maintenance crew for HVAC, you will need to train them on your specific system as well.
The other major obstacle would be a leak developing under the floor. Repairing this would require standard slab leak procedures. However, you would need to ensure that the repaired floor is capable of meeting the same weight requirements as the original floor. In a building like the crane maintenance facility mentioned earlier, the floor needs to be able to handle a great deal of weight.
Can I Use a System Like This at Home?
Radiant Floor Heating is available for home installations. In warmer climates it can be tied into your domestic water heating system for the occasional cool morning, and this may also be a good candidate for an electric system. Stay tuned and we will investigate residential use in a future article, for both new construction and retrofitting an existing home.