Just installed a Webasto FCF 16000 btu on our 37' trawler. Vented one so it goes to the master stateroom, the other to the saloon. Works great, a/c and heat. Not too concerned about forward cabin. I can't imagine needing 2 for a 34 ft. trawler. Bought ours from a dealer in Ontario, great price and exchange rate is in our favor. Installed under the settee.