7 Tips to Retrofit HVAC for Historic Buildings

7 Tips to Retrofit HVAC for Historic Buildings

The heating, ventilation and air conditioning system is one part of your building that when it works, you take it for granted. In the same vein, if it’s defective, you will really feel every minute that you are inside the structure. Installing this system in a new building is complicated enough, but retrofitting HVAC for historic buildings is a different story.

Retrofit HVAC for Historic BuildingsThe common misconception is that the AC will make the temperature inside cooler through the refrigerant. However, it’s more accurate to say the unit pushes out warm air and heat energy is transferred through the coil.

As for the central heating system, a furnace run by either gas or oil is installed usually in the garage or basement. Again, how it works is that combustion gasses produced by the furnace will go through the heat exchanger. The heat is then distributed throughout the house through a series of ducts. Below, we have compiled a list of guidelines to retrofit HVAC for historic buildings.

1. Considering the mini-duct option

A mini-duct system is a worthy option considering its small footprint. Just like its name suggests, the ducts are quite small. This means you can retrofit it without causing too much damage to the plaster or original materials. It operates much like the traditional ducts, although air is passed through the vestibules at a higher velocity. Bernoulli’s principle, which states that an uptick in speed will have a direct correlation to the drop in pressure or potential energy, will take effect here. This means that the temperature in the room will be much cooler.

2. Invest in modern HVAC for historic buildings

Old systems can be expensive to repair, and you have no guarantees that they would not fail in the future. For example, one innovation now is the variable refrigerant flow system, which doesn’t really utilize ducts to distribute air. It also requires a small footprint through a series of air handlers that can be retrofitted easily.

3. Apprise yourself of the building code in your area

If your district is declared as historic, you can’t introduce changes without securing permits, unfortunately. This includes the HVAC for historic buildings. For smaller structures, the individual contractor can assess the capacity and the type of system to be installed. In contrast, it becomes more complex for bigger buildings.

4. Your existing HVAC doesn’t have to be mothballed

Have a certified contractor check your existing system for any “reasonable” attendant costs. The lifespan of HVAC for historic buildings can actually be extended with proper maintenance and overhaul. So, try to ask your contractor for any salvageable parts in order to save on cost. Of course, old units may sometimes still be using R-22s. In fact, these are already banned from use because of the dangers they pose to the environment. In that case, it would have to be recovered and probably recycled.

5. Exterior modifications are not allowed

While the state may be more forgiving regarding the changes to the interior of the building, the exterior is virtually untouchable. That means no HVAC system jutting out of the building that may destroy the integrity of the structure’s appearance.

6. Budget for maintenance cost

Who said maintaining a historic building is going to be cheap? Aside from the upkeep, it’s what you don’t see that can cost you. This means the electrical, plumbing and HVAC systems. Find from your local state or park service if you can avail of tax incentives for historic properties. Some states do give some incentives for owners to make sure historic structures are not left in disrepair.

7. Moisture is not your friend

Moisture from condensation could be very damaging to any old structure. Therefore, you should deal with a contractor that specializes in HVAC for historic buildings to prevent that from happening. After all, moisture not only destroys ancient wood but also stains the plasters and walls.

If you have any other questions about retrofit HVAC for historic buildings, contact The Severn Group for more information. In addition, consider checking out our other blogs on HVAC tips.

The Severn Group delivers high-quality service to its clients from conceptual design through project punch list. Design review, estimating, and administrative resources are staffed from our headquarters in Maryland.