Upon arrival, we noticed a smell. It improved a little when we opened the windows, but the smell was still there. Some in our party had to sleep with windows open, and it was a cold night, so not very restful. When we awoke, I noticed the thermostat had the following readings: Air Quality Poor - Volatile organic compounds High / Carbon Dioxide High. We opened all the windows, and the air quality improved to Fair. We all had symptoms - scratchy throats and congestion. We left the property and booked a hotel for the night. The total cost of the trip increased for us because we could no longer cook our meals and had to pay for a hotel at the last minute. The owner provided a partial refund. He said the problem was a faulty thermostat, according to his HVAC person, but this doesn't explain the smell and experience we had from breathing the air. Vrbo customer service said it was up to the owners to determine the refund, even with evidence of poor air quality. Disappointed with the owner's and Vrbo's response.