energy recovery ventilation system

The first thing to consider is how big of a system do you need - this is generally based off of # of bedrooms & square footage. As for the layout - that is based on the layout of your house. While some systems are designed to run into each room, that is rarely needed. In many cases one or two returns with an equal number of supplies is more than adequate. For example a single story home, I would possibly put a return in the Living Room with a Supply by the bedrooms (or simply in the master) assuming they are not close by each other. For a two story - I would probably put either the supply or return in the lower level with the other upstairs by the stairwell As for recommendations - it comes down to size, budget, features, locations - for DIY you might want to look into Fantec as many are available to DIYers & easy to install As for condensation - an ERV is not going to solve it - it might help reduce the issues but you need to make sure that you keep the humidity levels down (i.e. use kitchen & bath exhausts) not set a humidifier to high (you are looking for 20-25% max) An ERV will help moderate the amount of humidity in the air by allowing some from the return to stay in the house instead of being all exhausted like an HRV would do For More: http://thehtrc.com/2015/faq-window-wall-condensation-iced & http://thehtrc.com/2013/bs4d-ventilation-strategies