After implementing all of the great advice from everyone here on my home energy upgrades, I am now working on upgrading our church. I’d like some thoughts on the HVAC system updates we are planning to make. We had an energy audit conducted as part of our planning process. (See link below.) The church doesn’t have any reserves so anything we do we will have to raise the funds for. We’ve estimated we could raise around $320k for air sealing, insulation, HVAC upgrades. We’re also spending around $30k / year in HVAC maintenance contracts and repairs plus our utility bills are around $30k / year. I would like to get both of these ongoing expenses down as part of the process. We’ve already saved around $6k/year setting back some of the thermostats.

The church offices are occupied 5 days / week, the meeting rooms are used 3x per week, and the sanctuary is occupied 3x per week. I did a fuel based heat load calculation which came out to be 450k BTU/hr.

The boiler is 40+ years and some of the burners are missing. I was told it had a fire and they could no longer get parts for it. Some of the fan coils that feed the meeting rooms are located in areas which impede the air flow. My original thought is to put cold climate ducted heat pumps in to condition the meeting rooms and install a high efficiency boiler which would just condition the sanctuary. We’d still be burning gas, have the old fan coils to deal with, and would still have the high cost maintenance contracts for the boiler/chiller. One of the church members would also like to move the chiller to one of the flat roofs to open up the space. I also had the thought of forgoing the boiler and installing gas furnaces in place of the fan coils for the sanctuary.

We’re in climate zone 4a and we have natural gas.

https://devougood.sharepoint.com/:b:/s/SharedFiles/ER1EL396eeRKocVLHSg_LboBhOLt6seshilNCaIet524BA?e=aCfrRb

Thanks for your help!