The environment inside laying hen houses has an important effect on hen productivity, health, and well-being. Heat exchangers (HEs) can recover waste heat in ventilation exhaust to reduce supplemental heating needs while maintaining a greater fresh air exchange rate. For laying hen houses, there is limited information on the effect of heat recovery ventilation (HRV). Thus, the objective was to evaluate an air-to-air HE for manure belt drying ventilation in aviary laying hen housing. Temperature (T), relative humidity, ammonia, and manure dry matter (DM) content were characterized during a 4-wk period in October 2018. In weeks 2 and 4, the HRV was shut down and compared to weeks 1 and 3 when the HRV was operational. Average (±SD) ambient T was 10.6°C ± 4.0°C, similar for the 4-wk period. Heat exchanger efficiency was 75.07% ± 9.4% with the average supply temperature increased by 10.0°C ± 3.4°C and an average of 93.94 ± 31 kW heat recovered. Average indoor T (23.1°C ± 0.5°C) was warmer as a function ambient T and daily average T range was lower with HRV (1.8°C ± 0.7°C) compared to without HRV (22.2°C ± 1.2°C; 3.1°C ± 1.1°C). Seven days after manure removal, final average manure DM was 40.6% ± 3.1% (without HRV) and 60.0% ± 3.3% (with HRV). Implementation of HRV positively influenced indoor thermal environment by maintaining less dynamic diurnal fluctuations and greater temporal T uniformity.