This tech blog was written by our engineer Bill Meyer, of the Cambridge Air Solutions Applications Engineering team.
“Spec” buildings… You gotta love ‘em.
We, at Cambridge are frequently involved with heating “spec” buildings. You know how it goes: a developer puts up the shell, pours the concrete slab, heats the building to a minimum temperature the closes it up with no plans for ventilation. At some point in the future, the developer signs up a tenant and proceeds with the tenant fit-out. That is where our story begins.
The 200,000 sq. ft., 32’ high, uninsulated tilt wall building in Kansas City was erected in 2017 but was not occupied until 2019. In February 2020 our Regional Sales Manager learned from the Property Manager that the tenant was experiencing problems: condensation on the walls and the heaters were not maintaining the desired 55°F space temperature (although the design temperature was 50°F). A Cambridge Applications Engineer was asked to follow up to see if there was anything we could do to help.
Cambridge had participated in a “Building Burp Test” for a similar building in Allentown, PA. The test consisted of running the heating system continuously for 48 hours. The heaters were turned off, the building was ventilated with 1.5 air changes for one hour, and the heaters were turned back on. The indoor moisture level was reduced by 18%, based on datalogger results.
The tenant immediately implemented a similar plan to that outlined in the “Burp Test.” The process helped to dry out the building, but the heaters were still not operating as they should. The next step was to have a Cambridge’s Service Technician visit the job. He was able to get the four Cambridge heaters operating properly by replacing faulty discharge temperature sensors and setting the discharge temperatures to 160°F. The tenant was then able to maintain the desired 55°F space temperature.
Our experience is that providing ventilation significantly reduces moisture problems when buildings are closed up and the concrete slab is curing.