I purchased the Quadra Fire Castile and I'm currently planning the install. Is the Top Vent Adapter kit required for an "up and out" installation or may a person substitute a double walled "T" (the bottom of the T capped and used for cleaning access) plus a vertical (approximately 60") run, with double walled pipe, then out. My dealer does not have the Top Vent Adapter Kit in stock. Thanks in advance for replies and advice!