To some, energy efficiency and older buildings do not go together, but here at Rhodes Hall we are trying to prove you wrong. We have teamed up with Southface (or they with us rather) to create guidelines and a point system for LEED-like certification of the energy efficient rehab of historic buildings. The starting point of that being the inherent greenness of reusing an existing building to begin with.
Demolishing one building to build new and “more energy efficient” is like flaunting your choice of compostable paper plates and then throwing them away. YOU’VE MISSED 3/4 OF THE POINT!!
So, RH is serving as a pilot project to this green-rehab initiative. As we make necessary repairs to our building this year we are also making energy efficient upgrades, the biggest issue of course being climate control in the building.
While RH was formerly heated fairly efficiently by radiators (gas boiler in basement), the AC in the summer was another matter. Window units chugged noisily in all the downstairs and 2nd floor rooms while on the 3rd floor a central HVAC system kept us mostly cool but also cooled the uninsulated attic through leaks in the ducts. After much research and debate on the part of the Southface and The Georgia Trust and more debate before approval by the Board, we installed a central HVAC system (heat inverter?) downstairs zoned so that C’s office and the kitchen can be blocked off and controlled separately from the rest of the main floor which is often not “in use.” This was ideal for the museum/events space of our building, the least visible system we could install, but there is nowhere for ducts to run on the 2nd floor so up there, where most of our offices are, we installed top of the line split system electric units which are minimally invasive (least damage to the building itself and most removable), very efficient, and don’t block windows.
The basement ceiling and the attic were insulated with spray foam which has made the attic remarkably temperate year-round.
So how is it all working out?
Well, this is still a big building with high ceilings (for hot air to rise) and opulently expansive single-paned windows. On the first floor, the central heating does an excellent job of warming the entire area*, but on the 2nd and, subsequently the 3rd floors where we put in our 9-5, we are sorely missing the radiators. Here’s what seems to be the problem:
- the individual room units are operated on a room by room basis, meaning the entire floor (notably the center hall and large bedroom opening onto that) are rarely heated. These large spaces of cold air make it harder to heat up our offices and, even if we close the door, we must pass through these unconditioned spaces to get to the bathroom, the copier, or any other room.
- speaking of the bathroom, they did not receive any climate control at all and, since the 1st and 2nd floor bathrooms open onto unoccupied (and thus unconditioned) rooms, they are even colder, not an ideal place to pull your pants down. We got space heaters which take the edge off but the heat unfortunately is also rising into that 12 foot ceiling space!
- there is no heat from the 2nd floor to rise up and warm the 3rd floor as there once was, so that by midday it is colder upstairs than ever (if the central air up here was actually warming that might help but i can’t say that it is)
- we won’t even go into the aesthetics of the things.
We have miles to go before our work here is done. Work on the windows for instance—fixing drafts, adding storm windows—may help heat retention throughout the building but we still have to turn on the heat and I don’t expect to come to love these Mitsubishi split system units.
I say, if you’ve got radiators then by all means maintain them and if at all possible find a way to install central air on all levels for the summer months. save the split system hvac units for hotel rooms or other closed off and smaller spaces. Despite the selling points of the Mitsubishi units (they ARE quiet and good air conditioners and efficient) I’m not sure they were ideal for us here, then again, anything is efficient if you don’t turn it on.
I just ran across something on ZONE CONTROL on the US Dept of Energy website that better says I was trying to say about heating the whole house vs. just the rooms you are sitting in and something in between.
They write that “one way to save energy.. is to retrofit systems to provide separate control for different areas of large homes (RH). Zone control is most effective when large areas of the home are not used often or are used on a different schedule than other parts of the home.”—At RH this would definitely be the main floor/event space, and possibly the central areas of the 2nd floor, although… “Zone control works best in homes designed to operate in different heating zones, with each zone insulated from the others. In homes not designed for zone control (RH), leaving one section at a lower temperature could cause comfort problems in adjacent rooms because they will lose heat to the cooler parts of the home (unconditioned spaces).”
It goes on to say that you can of course enforce zone control/”insulation” by closing doors which we reluctantly do at RH right now though it shuts us off from each other. However, social/work interaction aside this is also not an entirely effective solution as everyone’s office opens onto the cooler central space and thus there is a lot of opening and closing doors. It would probably be advantageous to heat the central spaces daily in conjunction with our offices, thus providing a more reasonable level of comfort all around. let’s put these energy efficient units to work! sigh.
* update in January: The HVAC system downstairs is failing miserable due to several likely factors: the basement now has NO heat where it was once quite toasty thanks to the boiler, this makes it harder for the heat inverter system to warm up and provide properly warm air to the 1st floor, it also means there is a major updraft from the basement door (we use the basement which is partially finished but unconditioned), even though, yes, there is insulation in the floor joists below the 1st floor.