Thermal Comfort

Average temperatures of the dining room, library, and living room were plotted on the psychrometric chart to see where those rooms performed with respect to the comfort zone. 

All of the rooms are slightly below the comfort zone, though it should be remembered that the "comfort zone" for this chart uses modern definitions of thermal comfort - for a seated individual, in a short sleeve shirt. The comfort zone for which historic homes were built for is both cooler, and likely has the expectation that people in the house will dress appropriately as the seasons change. 

The surface temperatures of the floors indicate that the crawlspaces aren’t having much if any impact on the thermal comfort of the occupants in the rooms. Those temperatures are relatively consistent with the ambient air, globe, and mean radiant temperatures in the dining room, library, and living room. It is when those temperatures are compared with the surface temperatures of the glazing that it can be seen that conductive heat losses through the glazing have the greatest affect on thermal comfort in the house.

Recommendations

It is clear from the data gathered that the double-glazed windows in the living room are much more effective at preventing heat loss than the single-glazed windows. For this reason the best strategy for preventing heat loss, and consequently energy loss, would be to continue the pattern of storm windows which have been installed in bedroom #1. 

While uninsulated, unsealed glazing isn’t nearly as effective in preventing both kinds of loss, it is an improvement over the existing conditions. In the rooms with curtains and blinds, those can be drawn at night to provide additional layers of insulation against heat loss. This strategy does leave out the dining room, which has the biggest problem with heat loss coupled with no solar gain during the winter. In this case the addition of storm windows will help prevent some loss of heat, but it will still likely be one of the colder rooms in the house because of its orientation and the amount of exterior wall which is glazed. 

Therefore it should simply be accepted as being a different thermal environment than the other rooms, which can add greatly to the overall thermal delight of the house.

Close the outdoor air damper. The introduction of outdoor air to the mixing chamber is lowering system performance and lowering the temperature of the warm air delivered to the living spaces. 

Open the return air damper. The pneumatic servo that operates the return air damper is either not functioning or functioning erratically. If the return air damper were set to remain in the full open position better advantage could be taken of the heated air already in the air handling system.

Repair and reconnect the pre-heating coil in the mixing chamber. Increasing the temperature of the air being delivered to the ductwork will go a long way towards increasing thermal comfort, and would be a cost effective method of overcoming deficiencies in the fin-tube insert radiators. 

Check the boiler settings. Although we do not know the original design parameters for boiler efficiency, it is our feeling that the boiler could be ìtweakedî to burn less gas. This adjustment should take place after the changes mentioned above so the technician making the modification can ascertain system requirements.

Locate the defective fin-tube radiators. Our readings of the steam delivery pipes indicated that steam was getting through some locations, and fin-tube radiators were acting erratically. We did not have the time in this study to fully analyze this problem, but our data points towards a clogging or valve operation problem in the steam system. 

Check the fresh water supply (makeup water) source that feeds the steam system. One possible reason for clogs in the steam lines is mineral deposits from makeup water. Insure that makeup water is appropriately processed prior to its introduction to the steam lines. The maintenance company that services the boiler should be able to determine proper chemical components of makeup water. 

These modifications have been listed in the order of impact and cost effectiveness. As each item is checked off, some improvement should be recognized in the thermal comfort of the home, and as the system works more efficiently, gas consumption should drop.

Our calculations and the energy scheming program also show that a significant amount of heat loss may be prevented if storm or double paned windows are installed. 

Even if infiltration were a larger factor in heat loss, storm windows would be less intrusive than any method of preventing heat loss through infiltration. Infiltration is very hard to fix in a house, it is much easier just to build a relatively tight building than to fix it later. This goes double when you consider that this house is a historical house, many of the parts of it cannot be found today. Other methods like blown in insulation would require damaging the irreplaceable walls in the Watzek House. Making the windows smaller in the dining room or the living room would greatly diminish the wonderful light qualities that those rooms currently have.